Thesis about discourse
-
Upload
blessedkkr -
Category
Technology
-
view
2.699 -
download
0
Transcript of Thesis about discourse
![Page 1: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/1.jpg)
DISCOURSESEMANTICSOFS-MODIFYING ADVERBIALS
KatherineM. Forbes
A DISSERTATION
in
Linguistics
Presentedto theFacultiesof theUniversityof Pennsylvaniain Partial
Fulfillment of theRequirementsfor theDegreeof Doctorof Philosophy
2003
BonnieWebber, Supervisorof Dissertation Ellen Prince,Supervisorof Dissertation
DonaldA. Ringe,GraduateGroupChair Aravind Joshi,CommitteeMember
RobinClark,CommitteeMember
![Page 2: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/2.jpg)
Acknowledgements
I wish to thankBonnieWebber. Without herpatienceandherseeminglyendlessdepthsof insight,
I might never have completedthis thesis.I amenormouslygratefulfor herguidance.
I alsoowe many thanksto Ellen Prince. Sheis an intellectualleaderat Pennwho hashelped
many, includingme,find away throughthejungleof discourseanalysis.
I amindebtedto every professorwho hastaughtme. Specialthanksto RobinClark for beinga
memberof my dissertationcommittee.
I amverylucky to haveworkedwith Aravind Joshi.Heis acontinualsourceof knowledgein the
DLTAG meetings.Thefield of computationallinguisticshasalreadybenefitedfrom his sentence-
level work; I fully expectheandBonniewill producesimilarly usefulresultswith DLTAG.
Also in DLTAG, Eleni Miltsakaki andRashmiPrasad,andlaterCassandreCreswellandJason
Teepleall providedstimulationandsolace.Theirgreatcompany andgreateffort onDLTAGprojects
taughtme to appreciatehow muchcanbe donewhenmindswork together. I look forward to the
chanceto work with themin thefuture.
I amalsothankfulto MarthaPalmer, PaulKingsbury, andScottCottonfor allowing meto work
with themon thePropbankprojectandsupplementbothmy incomeandmy work in discourse.
Onapersonalnote,theForbes,Finley, andRiley familiesdeserve thanksfor giving meloveand
diversionandbalanceandtalkingmethroughmy education.Mostof all, thanksto EnricoRiley, for
beingeverythingto me.
ii
![Page 3: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/3.jpg)
ABSTRACT
DISCOURSESEMANTICSOFS-MODIFYING ADVERBIALS
KatherineM. Forbes
Supervisors:BonnieWebberandEllen Prince
In this thesis,we addressthequestionof why certainS-modifyingadverbialsareonly interpretable
with respectto thediscourseor spatio-temporalcontext, andnot just their own matrix clause.It is
not possibleto list theseadverbialsbecausethesetof adverbialsis compositionalandthereforein-
finite. Instead,we investigatethemechanismsunderlyingtheir interpretation.Wepresentacorpus-
basedanalysisof the predicateargumentstructureandinterpretationof over 13,000S-modifying
adverbials. We useprior researchon discoursedeixis andclause-level predicatesto studythe se-
manticsof theargumentsof S-modifyingadverbialsandthesyntacticconstituentsfrom which they
canbederived. We show thatmany S-modifyingadverbialscontainsemanticargumentsthatmay
notbesyntacticallyovert,but whoseinterpretationneverthelessrequiresanabstractobjectfrom the
discourseor spatio-temporalcontext. Prior work hasinvestigatedonly a smallsubsetof thesedis-
courseconnectives; at theclause-level theirsemanticshasbeenlargely ignoredandat thediscourse
level they areusuallytreatedas“signals”of predefinedlists of abstractdiscourserelations.Our in-
vestigationshedslight on thespaceof relationsimpartedby amuchwidervarietyof adverbials.We
furthershow how theirpredicateargumentstructureandinterpretationcanbeformalizedandincor-
poratedinto a rich intermediatemodelof discoursethataloneamongothermodelsviews discourse
connectivesaspredicateswhosesyntaxandsemanticsmustbespecifiedandrecoverableto interpret
discourse.It is notonly dueto theirargumentstructureandinterpretationthatadverbialshavebeen
treatedasdiscourseconnectives,however. Our corpuscontainsadverbialswhosesemanticsalone
doesnot causethemto beinterpretedwith respectto abstractobjectinterpretationsin thediscourse
or spatio-temporalcontext. Weexploreotherexplanationsfor why theseadverbialsevokediscourse
context for their interpretation;in particular, weshow how theinteractionof prosodywith theinter-
pretationof S-modifyingadverbialscancontribute to discoursecoherence,andwe alsoshow how
S-modifyingadverbialscanbeusedto convey implicatures.
iii
![Page 4: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/4.jpg)
Contents
Acknowledgements ii
Abstract iii
Contents iv
List of Tables x
List of Figures xiv
1 Intr oduction 1
1.1 TheProblem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Contributionsof theThesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 ThesisOutline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Anaphora and DiscourseModels 6
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Descriptive Theoriesof DiscourseCoherence . . . . . . . . . . . . . . . . . . . . 8
2.2.1 An Early EncompassingDescription. . . . . . . . . . . . . . . . . . . . . 8
2.2.2 Alternative Descriptionsof PropositionalRelations . . . . . . . . . . . . . 10
2.2.3 DiscourseRelationsasConstraints. . . . . . . . . . . . . . . . . . . . . . 12
2.2.4 AbducingDiscourseRelationsby Applying theConstraints . . . . . . . . 14
2.2.5 Interactionof DiscourseInferenceandVP Ellipsis . . . . . . . . . . . . . 17
iv
![Page 5: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/5.jpg)
2.2.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3 A Three-TieredModelof Discourse . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3.1 TheThreeTiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3.2 Coherencewithin DiscourseSegments. . . . . . . . . . . . . . . . . . . . 22
2.3.3 ModelingLinguisticStructureandAttentionalStateasaTree . . . . . . . 23
2.3.4 Introductionto DiscourseDeictic Reference. . . . . . . . . . . . . . . . . 25
2.3.5 Retrieving Antecedentsof DiscourseDeixis from theTree . . . . . . . . . 27
2.3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.4 A TreeStructurewith aSyntax-SemanticInterface . . . . . . . . . . . . . . . . . 33
2.4.1 ConstituentsandTreeConstruction . . . . . . . . . . . . . . . . . . . . . 33
2.4.2 TheSyntaxSemanticInterface . . . . . . . . . . . . . . . . . . . . . . . . 34
2.4.3 Retrieving Antecedentsof Anaphorafrom theTree . . . . . . . . . . . . . 36
2.4.4 TheNeedFor UpwardPercolation. . . . . . . . . . . . . . . . . . . . . . 36
2.4.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.5 A Descriptive Theoryof DiscourseStructure. . . . . . . . . . . . . . . . . . . . . 38
2.5.1 AnalyzingText Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.5.2 TheNeedfor Multiple Levelsof DiscourseStructure . . . . . . . . . . . . 42
2.5.3 “Elaboration”asReference. . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.5.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.6 A SemanticTheoryof DiscourseCoherence. . . . . . . . . . . . . . . . . . . . . 48
2.6.1 AbstractObjects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
2.6.2 A FormalLanguagefor Discourse. . . . . . . . . . . . . . . . . . . . . . 53
2.6.3 Retrieving Antecedentsof Anaphorafrom theDiscourseStructure. . . . . 57
2.6.4 A Systemfor InferringDiscourseRelations . . . . . . . . . . . . . . . . . 57
2.6.5 ExtendingtheTheoryto Cognitive States . . . . . . . . . . . . . . . . . . 62
2.6.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
2.7 Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
2.7.1 Proliferationof DiscourseRelations . . . . . . . . . . . . . . . . . . . . . 64
v
![Page 6: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/6.jpg)
2.7.2 Useof LinguisticCuesasSignals . . . . . . . . . . . . . . . . . . . . . . 66
2.7.3 StructuralandAnaphoricCuePhrases. . . . . . . . . . . . . . . . . . . . 69
2.7.4 Comparisonof DLTAG andOtherModels . . . . . . . . . . . . . . . . . . 71
2.7.5 RemainingQuestions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
2.8 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
3 SemanticMechanismsin Adverbials 78
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
3.2 Linguistic BackgroundandDataCollection . . . . . . . . . . . . . . . . . . . . . 79
3.2.1 Functionof Adverbials . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
3.2.2 Structureof PPandADVP . . . . . . . . . . . . . . . . . . . . . . . . . . 81
3.2.3 DataCollection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
3.2.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
3.3 AdverbialModificationTypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
3.3.1 Clause-Level Analysesof ModificationType . . . . . . . . . . . . . . . . 87
3.3.2 Problemswith CategoricalApproaches . . . . . . . . . . . . . . . . . . . 91
3.3.3 ModificationTypesasSemanticFeatures . . . . . . . . . . . . . . . . . . 92
3.3.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
3.4 AdverbialSemanticArguments. . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
3.4.1 (Optional)Argumentsor Adjuncts? . . . . . . . . . . . . . . . . . . . . . 94
3.4.2 ExternalArgumentAttachmentAmbiguity . . . . . . . . . . . . . . . . . 98
3.4.3 SemanticRepresentationof ExternalArgument . . . . . . . . . . . . . . . 103
3.4.4 SemanticArgumentsasAbstractObjects . . . . . . . . . . . . . . . . . . 104
3.4.5 Numberof AbstractObjects . . . . . . . . . . . . . . . . . . . . . . . . . 107
3.4.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
3.5 S-Modifying PPAdverbials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
3.5.1 ProperNouns,Possessives,andPronouns . . . . . . . . . . . . . . . . . . 111
3.5.2 Demonstrative andDefiniteDeterminers. . . . . . . . . . . . . . . . . . . 114
3.5.3 IndefiniteArticles,GenericandPluralNouns,andOptionalArguments . . 117
vi
![Page 7: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/7.jpg)
3.5.4 PPandADJPModifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
3.5.5 OtherArguments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
3.5.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
3.6 S-Modifying ADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
3.6.1 SyntacticallyOptionalArguments . . . . . . . . . . . . . . . . . . . . . . 135
3.6.2 Context-DependentADVP Adverbials. . . . . . . . . . . . . . . . . . . . 139
3.6.3 Comparative ADVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
3.6.4 SetsandWorlds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
3.6.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
3.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
4 Incorporating Adverbial Semanticsinto DLTAG 157
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
4.2 Syntax-SemanticInterfacesat theSentenceLevel . . . . . . . . . . . . . . . . . . 158
4.2.1 TheRoleof theSyntax-SemanticInterface . . . . . . . . . . . . . . . . . 158
4.2.2 LTAG: LexicalizedTreeAdjoining Grammar . . . . . . . . . . . . . . . . 159
4.2.3 A Syntax-SemanticInterfacefor LTAG DerivationTrees . . . . . . . . . . 161
4.2.4 A Syntax-SemanticInterfacefor LTAG ElementaryTrees . . . . . . . . . 166
4.2.5 Comparisonof Approaches. . . . . . . . . . . . . . . . . . . . . . . . . . 169
4.2.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
4.3 Syntax-SemanticInterfacesat theDiscourseLevel . . . . . . . . . . . . . . . . . . 171
4.3.1 DLTAG: LexicalizedTreeAdjoining Grammarfor Discourse. . . . . . . . 171
4.3.2 Syntax-SemanticInterfacesfor DerivedTrees. . . . . . . . . . . . . . . . 179
4.3.3 A Syntax-SemanticInterfacefor DLTAG DerivationTrees . . . . . . . . . 190
4.3.4 Comparisonof Approaches. . . . . . . . . . . . . . . . . . . . . . . . . . 218
4.3.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
4.4 DLTAG AnnotationProject . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
4.4.1 Overview of Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
4.4.2 PreliminaryStudy1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
vii
![Page 8: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/8.jpg)
4.4.3 PreliminaryStudy2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
4.4.4 FutureWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
4.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
5 Other WaysAdverbials Contrib ute to DiscourseCoherence 229
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
5.2 Focus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
5.2.1 ThePhenomena. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
5.2.2 Information-StructureandTheoriesof StructuredMeanings . . . . . . . . 232
5.2.3 Alternative Semantics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
5.2.4 Backgroundsor Alternatives? . . . . . . . . . . . . . . . . . . . . . . . . 237
5.2.5 Contrastive Themes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
5.2.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
5.3 FocusSensitivity of Modifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
5.3.1 FocusParticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
5.3.2 OtherFocusSensitive Sub-ClausalModifiers . . . . . . . . . . . . . . . . 244
5.3.3 S-Modifying “FocusParticles” . . . . . . . . . . . . . . . . . . . . . . . . 249
5.3.4 FocusSensivity of S-Modifying Adverbials . . . . . . . . . . . . . . . . . 254
5.3.5 FocusingS-Modifying Adverbialsto Evoke Context . . . . . . . . . . . . 258
5.3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
5.4 Implicatures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
5.4.1 GriceanImplicature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
5.4.2 PragmaticandSemanticPresupposition. . . . . . . . . . . . . . . . . . . 267
5.4.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
5.5 UsingS-Modifying Adverbialsto Convey Implicatures . . . . . . . . . . . . . . . 270
5.5.1 Presupposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
5.5.2 ConversationalImplicatures . . . . . . . . . . . . . . . . . . . . . . . . . 271
5.5.3 Interactionof FocusandImplicature . . . . . . . . . . . . . . . . . . . . . 277
5.5.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
viii
![Page 9: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/9.jpg)
5.6 OtherContributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
5.6.1 DiscourseStructure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
5.6.2 Performatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
5.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
6 Conclusion 279
6.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
6.2 FutureDirections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Bibliography 285
ix
![Page 10: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/10.jpg)
List of Tables
2.1 Main Categoriesof [HH76]’s RelationsbetweenPropositions. . . . . . . . . . . . 10
2.2 Main Categoriesof [Lon83]’s RelationsbetweenPropositions . . . . . . . . . . . 10
2.3 Main Categoriesof [Mar92]’s RelationsbetweenPropositions . . . . . . . . . . . 11
2.4 Main Categoriesof [Hob90]’s RelationsbetweenPropositions . . . . . . . . . . . 12
2.5 [Keh95]’sCause-Effect Relations. . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.6 [Keh95]’sResemblanceRelations . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.7 [GS86] Changesin DiscourseStructureIndicatedby LinguisticExpressions. . . . 21
2.8 CenteringTheoryTransitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.9 [Web91]’s Classificationof DiscourseDeicticReference . . . . . . . . . . . . . . 26
2.10 Organizationsof RSTRelationDefinitions . . . . . . . . . . . . . . . . . . . . . 39
2.11 Evidence:RSTRelationDefinition . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.12 Volitional-Cause:RSTRelationDefinition . . . . . . . . . . . . . . . . . . . . . . 42
2.13 Elaboration:RSTRelationDefinition . . . . . . . . . . . . . . . . . . . . . . . . 44
2.14 [Ven67]’s ImperfectandPerfectNominalizations . . . . . . . . . . . . . . . . . . 49
2.15 [Ven67]’s LooseandNarrow Containers. . . . . . . . . . . . . . . . . . . . . . . 50
2.16 DICE: discourserelationdefinitions . . . . . . . . . . . . . . . . . . . . . . . . . 58
2.17 DICE: Indefeasibleaxioms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
2.18 DICE: Defeasiblelaws on world knowledge . . . . . . . . . . . . . . . . . . . . . 59
2.19 DICE: Defeasiblelaws on discourseprocesses. . . . . . . . . . . . . . . . . . . . 60
2.20 DICE: Deductionrules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2.21 [Kno96]’s Featuresof DiscourseConnectives . . . . . . . . . . . . . . . . . . . . 68
x
![Page 11: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/11.jpg)
3.1 Non-DerivedandDerivedAdverbs . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3.2 tgrep Resultsfor S-AdjoinedADVP andPPin WSJandBrown Corpora. . . . . . 85
3.3 TotalS-AdjoinedAdverbialsin WSJandBrown Corpora . . . . . . . . . . . . . . 86
3.4 [Ale97]’s ModificationTypes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
3.5 [Ern84]’s ModificationTypes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
3.6 [KP02]’sModificationTypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
3.7 [Gre69]’s SyntacticTestsfor DistinguishingVP andSModification . . . . . . . . 99
3.8 SemanticInterpretationsof [Ern84]’s ModificationTypes . . . . . . . . . . . . . . 103
3.9 AbstractObjectInterpretations. . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
3.10 ApproximateCountsof TokensandTypesof someInternalPParguments . . . . . 111
3.11 PPAdverbialswith ProperNounor YearInternalArgument . . . . . . . . . . . . 111
3.12 PPAdverbialwith Possessive ProperNounInternalArgument . . . . . . . . . . . 112
3.13 PPAdverbialswith PronominalInternalArgument . . . . . . . . . . . . . . . . . 113
3.14 PPAdverbialwith Possessive Pronoun. . . . . . . . . . . . . . . . . . . . . . . . 114
3.15 ApproximateCountsof TokensandTypesof someInternalPParguments . . . . . 114
3.16 PPAdverbialswith DefiniteConcreteObjectInternalArgument . . . . . . . . . . 115
3.17 PPAdverbialswith DefiniteAO InternalArgument . . . . . . . . . . . . . . . . . 115
3.18 PPAdverbialswith Demonstrative ConcreteObjectInternalArgument. . . . . . . 116
3.19 PPAdverbialswith Demonstrative AO InternalArguments . . . . . . . . . . . . . 117
3.20 ApproximateCountsof TokensandTypesof someInternalPParguments . . . . . 118
3.21 PPAdverbialwith IndefiniteConcreteObjectInternalArgument . . . . . . . . . . 118
3.22 PPAdverbialwith IndefiniteAO InternalArgument . . . . . . . . . . . . . . . . . 118
3.23 PPAdverbialwith RelationalIndefiniteAO InternalArgument . . . . . . . . . . . 119
3.24 PPAdverbialswith Genericor PluralConcreteObjectInternalArguments. . . . . 122
3.25 PPAdverbialswith Genericor PluralAO InternalArguments. . . . . . . . . . . . 122
3.26 PPAdverbialswith RelationalGenericAO InternalArguments. . . . . . . . . . . 123
3.27 ApproximateCountsof TokensandTypesof someInternalArgumentModifiers . . 124
3.28 Binary DefiniteInternalArgumentwith OvertArgument . . . . . . . . . . . . . . 125
xi
![Page 12: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/12.jpg)
3.29 Binary IndefiniteInternalArgumentwith Overt Argument . . . . . . . . . . . . . 125
3.30 Binary Genericor PluralInternalArgumentwith OvertArgument . . . . . . . . . 126
3.31 InternalArgumentwith aSpatio-TemporalADJ . . . . . . . . . . . . . . . . . . . 126
3.32 InternalArgumentwith ReferentialAdjective . . . . . . . . . . . . . . . . . . . . 127
3.33 InternalArgumentwith Non-ReferentialAdjective . . . . . . . . . . . . . . . . . 128
3.34 InternalArgumentwith DeterminerandNon-ReferentialAdjective . . . . . . . . . 128
3.35 InternalArgumentwith OrdinalAdjective . . . . . . . . . . . . . . . . . . . . . . 129
3.36 InternalArgumentwith Alternative Phrase. . . . . . . . . . . . . . . . . . . . . . 129
3.37 InternalArgumentwith DeterminerandAlternative Phrase . . . . . . . . . . . . . 129
3.38 InternalArgumentwith Comparative/Superlative Adjective . . . . . . . . . . . . . 130
3.39 InternalArgumentwith OtherSet-Evoking Adjectives. . . . . . . . . . . . . . . . 131
3.40 ApproximateCountsof TokensandTypesof someInternalPParguments . . . . . 131
3.41 PPAdverbialwith ReducedClauseInternalArgument . . . . . . . . . . . . . . . 132
3.42 PPAdverbialSummary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
3.43 ApproximateCountsof TokensandTypesof someADVP Adverbials . . . . . . . 135
3.44 Mis-TaggedPPAdverbials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
3.45 PP-like ADVP Adverbialswith Overt Arguments . . . . . . . . . . . . . . . . . . 136
3.46 PP-like ADVP Adverbialswith HiddenArgument . . . . . . . . . . . . . . . . . . 136
3.47 RelationalADJPwith Overt Argument. . . . . . . . . . . . . . . . . . . . . . . . 137
3.48 RelationalADVP Adverbialswith HiddenArgument . . . . . . . . . . . . . . . . 138
3.49 ApproximateCountsof TokensandTypesof someADVP Adverbials . . . . . . . 139
3.50 ADVP AdverbialConjunctions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
3.51 Mis-TaggedPPAdverbialConstructions. . . . . . . . . . . . . . . . . . . . . . . 142
3.52 Spatio-TemporalADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . . . . 143
3.53 AnotherSpatio-TemporalADVP Adverbial . . . . . . . . . . . . . . . . . . . . . 143
3.54 OtherSpatio-TemporalADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . 143
3.55 Spatio-TemporalMannerADVP Adverbials . . . . . . . . . . . . . . . . . . . . . 144
3.56 Deictic ADVP Adverbials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
xii
![Page 13: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/13.jpg)
3.57 Deictic-DerivedADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . . . . . 145
3.58 ApproximateCountsof TokensandTypesof someADVP Adverbials . . . . . . . 146
3.59 Comparative AdverbModifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
3.60 Comparative ADVP Adverbials. . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
3.61 SpecifiedComparative ADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . 147
3.62 Comparative-DerivedADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . . 148
3.63 Comparative Constructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
3.64 ApproximateCountsof TokensandTypesof someADVP Adverbials . . . . . . . 150
3.65 OrdinalADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
3.66 Ordinal-ly ADVP Adverbials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
3.67 Frequency ADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
3.68 EpistemicADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
3.69 DomainADVP Adverbials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
3.70 Non-SpecificSet-Evoking ADVP Adverbials . . . . . . . . . . . . . . . . . . . . 153
3.71 Multiply-FeaturedADVP Adverbials. . . . . . . . . . . . . . . . . . . . . . . . . 153
3.72 More Multiply-FeaturedADVP Adverbials . . . . . . . . . . . . . . . . . . . . . 153
3.73 Evaluative or Agent-OrientedADVP Adverbials. . . . . . . . . . . . . . . . . . . 154
3.74 ADVP AdverbialSummary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
4.1 Nine ConnectivesStudiedin [CFM�
02] . . . . . . . . . . . . . . . . . . . . . . . 223
4.2 AnnotationTagsfor theNineConnectivesStudiedin [CFM�
02] . . . . . . . . . . 224
4.3 LOC TagValues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
4.4 Inter-AnnotatorAgreement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
5.1 ADVP/PPAdverbialswith FocusParticleModifier . . . . . . . . . . . . . . . . . 260
5.2 Higher-OrderedEpistemicAdverbialsYielding Implicatures . . . . . . . . . . . . 271
5.3 Lower-OrderedEpistemicAdverbialsYielding Implicatures . . . . . . . . . . . . 273
5.4 Lower-OrderedQuantificationalAdverbialsYielding Implicatures . . . . . . . . . 274
5.5 Higher-OrderedQuantificationalAdverbialsYielding Implicatures . . . . . . . . . 274
xiii
![Page 14: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/14.jpg)
List of Figures
2.1 [HH76]’s Typesof Cohesion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Illustrationof [GS86]’s DiscourseModel . . . . . . . . . . . . . . . . . . . . . . . 20
2.3 Illustrationof [Web91]’s AttachmentOperation . . . . . . . . . . . . . . . . . . . 24
2.4 Illustrationof [Web91]’s AdjunctionOperation . . . . . . . . . . . . . . . . . . . 24
2.5 LDM Right-AttachmentOperation . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.6 LDM TreeStructurefor Example(2.58) . . . . . . . . . . . . . . . . . . . . . . . 36
2.7 LDM TreeStructurefor Example(2.59) . . . . . . . . . . . . . . . . . . . . . . . 37
2.8 RSTSchemas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.9 EvidenceRelation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.10 RSTConditionandMotivationRelations . . . . . . . . . . . . . . . . . . . . . . 43
2.11 [KOOM01]’sDiscourseModel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.12 [Ash93]’s Classificationof AbstractObjects . . . . . . . . . . . . . . . . . . . . . 52
2.13 SampleDRSs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
2.14 SampleSDRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2.15 ElementaryDLTAG Trees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
3.1 S-AdjoiningPPandADVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
3.2 S-AdjoinedDiscourseandClausalAdverbials . . . . . . . . . . . . . . . . . . . . 84
3.3 S-AdjoinedADVP andPPAdverbialsin PennTreebankI . . . . . . . . . . . . . . 84
3.4 [Ash93]’s Classificationof AbstractObjects . . . . . . . . . . . . . . . . . . . . . 105
3.5 SyntacticStructureof S-ModifyingPPAdverbials. . . . . . . . . . . . . . . . . . 110
xiv
![Page 15: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/15.jpg)
3.6 SyntacticStructureof S-ModifyingADVP Adverbials. . . . . . . . . . . . . . . . 134
4.1 ElementaryLTAG Trees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
4.2 LTAG DerivedTreeafterSubstitions. . . . . . . . . . . . . . . . . . . . . . . . . 160
4.3 LTAG DerivedTreeAfter Adjunction . . . . . . . . . . . . . . . . . . . . . . . . 161
4.4 LTAG DerivationTree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
4.5 SemanticRepresentationsof ��������� and � ������� . . . . . . . . . . . . . . . . . . . 163
4.6 SemanticRepresentationsof Johnwalks . . . . . . . . . . . . . . . . . . . . . . . 163
4.7 SemanticRepresentationsof ��������� , ��������� , ��������� , and� ���� "!#� . . . . . . . . . . . 164
4.8 SemanticRepresentationsof JohnoftenwalksFido . . . . . . . . . . . . . . . . . 164
4.9 SimplifiedSemanticRepresentationof ���$�%�&�� and� ���� "!'� . . . . . . . . . . . . . . 165
4.10 TheElementaryTreefor slide . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
4.11 TheSyntax-SemanticInterfacefor (*),+'-/. . . . . . . . . . . . . . . . . . . . . . . . 168
4.12 DLTAG Initial Treesfor SubordinatingConjunctions . . . . . . . . . . . . . . . . 172
4.13 DLTAG Auxiliary Treefor andand 0 . . . . . . . . . . . . . . . . . . . . . . . . . 173
4.14 DLTAG Auxiliary Treesfor DiscourseAdverbials . . . . . . . . . . . . . . . . . . 174
4.15 DLTAG Initial Treefor AdverbialConstructions. . . . . . . . . . . . . . . . . . . 177
4.16 DLTAG DerivedTreefor Example(4.18) . . . . . . . . . . . . . . . . . . . . . . 178
4.17 DLTAG DerivationTreefor Example(4.18) . . . . . . . . . . . . . . . . . . . . . 178
4.18 Illustrationof [Web91]’s AttachmentandAdjunctionOperations. . . . . . . . . . 179
4.19 Webber’s Adjunctionata Leaf . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
4.20 DerivedTreefor Example(2.41) . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
4.21 Substitutionin FTAG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
4.22 Adjunctionin FTAG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
4.23 LDM ElementaryDCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
4.24 DTAG ElementaryDCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
4.25 LDM List Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
4.26 DTAG R Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
4.27 [Gar97b]’s - -Substitution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
xv
![Page 16: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/16.jpg)
4.28 [Gar97b]’s - -Adjunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
4.29 First DTAG Derivationof Example(4.21) . . . . . . . . . . . . . . . . . . . . . . 186
4.30 SecondDTAG Derivationof Example(4.21) . . . . . . . . . . . . . . . . . . . . 186
4.31 StepOnein theSecondDTAG Derivationof Example(4.21) . . . . . . . . . . . . 187
4.32 StepTwo in theSecondDTAG Derivationof Example(4.21) . . . . . . . . . . . . 187
4.33 StepThreein theSecondDTAG Derivationof Example(4.21) . . . . . . . . . . . 188
4.34 StepFour in theSecondDTAG Derivationof Example(4.21) . . . . . . . . . . . 188
4.35 StepFive in theSecondDTAG Derivationof Example(4.21) . . . . . . . . . . . . 189
4.36 StepSix in theSecondDTAG Derivationof Example(4.21) . . . . . . . . . . . . 189
4.37 StepSevenin theSecondDTAG Derivationof Example(4.21) . . . . . . . . . . . 190
4.38 DLTAG ElementaryTreesfor Example(4.22) . . . . . . . . . . . . . . . . . . . . 191
4.39 SemanticRepresentationof ��12!�34��5�'! , ���&�6��!� and �������&�� . . . . . . . . . . . . . . . 192
4.40 DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.22) . . . 192
4.41 DLTAG ElementaryTreesfor Example(4.24) . . . . . . . . . . . . . . . . . . . . 193
4.42 SemanticRepresentationof� ���7� , � '!�! and ���8�"# . . . . . . . . . . . . . . . . . . 193
4.43 DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.24) . . . 194
4.44 DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.26) . . . 194
4.45 DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.28) . . . 195
4.46 LTAG DerivedandDerivationTreesfor Example(4.30) . . . . . . . . . . . . . . . 196
4.47 Quantifiersin French . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
4.48 [Kal02]’s . -Edgesfor Quantifiersin French . . . . . . . . . . . . . . . . . . . . . 197
4.49 [Kal02]’s . -DerivationGraph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
4.50 DLTAG DerivedTreeand . -DerivationGraphfor Example(4.28) . . . . . . . . . 199
4.51 Additional SemanticRepresentationfor (4.28)dueto . -DerivationGraph . . . . . 199
4.52 DLTAG DerivedTreeand . -DerivationGraphfor Example(4.32) . . . . . . . . . 200
4.53 Flexible Compositionin LTAG . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
4.54 DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.28) . . . 203
4.55 DLTAG ElementaryTreesfor Example(4.33) . . . . . . . . . . . . . . . . . . . . 204
xvi
![Page 17: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/17.jpg)
4.56 SemanticRepresentationof� �6� , � "���� , � �$��9 , �;: , � �6�� "!'<�=���!#� and ��34���>4����!#< . . . . . 204
4.57 DLTAG DerivedandDerivationTrees,. -DerivationGraphandSemanticsfor (4.33) 205
4.58 DLTAG ElementaryTreesfor Example(4.35) . . . . . . . . . . . . . . . . . . . . 206
4.59 SemanticRepresentationof� 34���7#!�?#5*!'�� "�@9 , �A: , �����6��� and �B�&��'! . . . . . . . . . . . . 207
4.60 DLTAG DerivedandDerivationTrees,. -DerivationGraph,andSemanticsfor (4.35) 207
4.61 DLTAG ElementaryTreesfor Example(4.37) . . . . . . . . . . . . . . . . . . . . 208
4.62 SemanticRepresentationof� �% , � � , ��<�!�45C�& ED;��� , �� "���� , �;: , �����6��� and �����#! . . . . . 208
4.63 DLTAG DerivedandDerivationTrees,. -DerivationGraphandSemanticsfor (4.37) 209
4.64 DLTAG ElementaryTreeandSemanticRepresentationfor ��<�!�'5C�@ in (4.39) . . . . 210
4.65 DLTAG DerivedandDerivationTrees,. -DerivationGraphandSemanticsfor (4.39) 210
4.66 DLTAG DerivationTreeand . -DerivationGraphfor Example(4.41) . . . . . . . . 212
4.67 ElementaryLTAG TreesandSemanticRepresentationsof� !#=�!'<�9 , � !#=�!'<�9 , ������F , � 12��<��� 214
4.68 ElementaryDLTAG Treesfor Examplefor example . . . . . . . . . . . . . . . . . 215
4.69 DerivationTreesfor PPDiscourseAdverbialswith QuantifiedInternalArguments. 216
4.70 DLTAG DerivedandDerivationTreesfor (4.32) . . . . . . . . . . . . . . . . . . . 218
4.71 AnotherRepresentationof theR Treein Figure4.26 . . . . . . . . . . . . . . . . 219
5.1 GriceanFramework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
xvii
![Page 18: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/18.jpg)
Chapter 1
Intr oduction
1.1 The Problem
Traditionally in linguistic theory, syntaxandsemanticsprovide mechanismsto build the interpre-
tationof a sentencefrom its parts;althoughit is non-controversiala sequenceof sentencessuchas
foundin (1.1) - (1.3)alsohasaninterpretation,themechanismswhichproduceit arenotdefined.
(1.1) Thereis a high degreeof stresslevel from the needto competeandsucceedin this ‘me
generation’.As a result,peoplehave becomemoreself-centeredover time.
(1.2)Johnhasfinally beenrewardedfor his greattalent.Specifically, hejust won a gold medal
for mogul-skiingin theOlympics.
(1.3)Thecompany interviewedeveryonewhoappliedfor theposition.In thisway, they consid-
eredall theiroptions.
Most discoursetheoriesgo beyond sentencelevel linguistic theory to explain how suchse-
quencesare put togetherto createa discourseinterpretation. Thesetheoriesevoke the notion
of abstractdiscourserelationsbetweendiscourseunits, provide lists of theserelationsof vary-
ing lengthand organization,andproposediscoursemodelsconstructedfrom theserelationsand
units. Someof thesemodelsproducecompositionalaccountsof discoursestructureand/orinter-
pretation([Pol96, Ash93, MT88, GS86];othersproduceaccountsfor how relationsbetweenunits
areinferred([Keh95, HSAM93, LA93]. Themajority make useof thepresenceof cuephrases, or
1
![Page 19: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/19.jpg)
discourseconnectives, treatingthemas“signals” of thepresenceof particulardiscourserelations.
In (1.1),for example,therelevantcuephraseis theadverbialasa result, andthediscourserelationit
signalsis frequentlyclassifiedasa resultrelation. Along with certainadverbials,thesubordinating
andcoordinatingconjunctionsarealsoclassifiedasdiscourseconnectivesin thesetheories.
DLTAG [FMP�
01, CFM�
02, WJSK03, WKJ99,WJSK99,WJ98] is a theorythatbridgesthe
gapbetweenclause-level anddiscourse-level theories,providing amodelof arich intermediatelevel
betweenclausestructureandhigh-level discoursestructure,namely, thesyntaxandsemanticsasso-
ciatedwith discourseconnectives. In DLTAG, discourseconnectivesarepredicates, akin to verbs
at theclauselevel, exceptthatthey takediscourseunitsasarguments.DLTAG proposesto build the
interpretationof thesepredicatesdirectly on topof theclause,usingthesamesyntacticandseman-
tic mechanismsthatarealreadyusedto build theclause.Basedon considerationsof computational
economyandbehavioral evidence,DLTAG arguesthatbothargumentsof subordinatingandcoor-
dinatingconjunctionscanberepresentedstructurally, but only oneargumentof adverbialdiscourse
connectivescomesstructurally;theotherargumentmustberesolvedanaphorically. However, while
DLTAG hasshown thatcertainadverbialsfunctionasdiscourseconnectives,it hasnot isolatedthe
subsetof adverbialswhich functionasdiscourseconnectivesfrom thesetof all adverbials.
Thesetof all adverbialsis a largeset;in fact,it is compositionalandthereforeinfinite[Kno96].
Becauseit is thusnot possibleto list all of the adverbialsthat function asdiscourseconnectives,
in this thesiswe investigatehow semanticsand pragmaticscausean adverbial to function as a
discourseconnective.
1.2 Contrib utions of the Thesis
This thesisextendstheDLTAG model,investigatingthesemanticsandpragmaticsunderlyingthe
behavioral anaphoricityof adverbialdiscourseconnectives. We presenta corpus-basedanalysisof
over13,000S-modifyingadverb(ADVP)andpreposition(PP)adverbialsin thePennTreebankCor-
pus[PT]. Weshow thatcertainadverbials,whichwecall discourseadverbials, canbedistinguished
semanticallyfrom otheradverbials,whichwecall clausaladverbials. Someclausaladverbialsfrom
ourcorpusareshown in (1.4),andsomediscourseadverbialsfrom ourcorpusareshown in (1.5).
2
![Page 20: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/20.jpg)
(1.4)Probably/Inmycity/In truth, womentake careof thehouseholdfinances.
(1.5)Asa result/Specifically/Inthisway, womentake careof thehouseholdfinances.
Themostfrequentlyoccurringclausalanddiscourseadverbialshave bothbeenclassifiedin the
literatureasdiscourseconnectives,dueto the fact that they seemto be interpretableonly with re-
spectto context. In this thesiswe will show that while syntaxcannotdistinguishthesetwo types
of adverbials,theirpredicateargumentstructureandinterpretationshows thatonly discourseadver-
bialsfunctionsemanticallyasdiscourseconnectives.
The syntaxandsemanticsof mostdiscourseadverbialshasnot beenwell studied. Generally,
only asmallsubset(thosethatoccurfrequently)havebeenaddressedatall. At theclauselevel these
areusuallydesignatedasthedomainof discourselevel research,andat thediscourselevel thefocus
is frequentlyon thediscourserelationthey “signal”. Our investigationshedslight on thespaceof
relationsimpartedby amuchwider varietyof adverbials.
In our analysiswe draw on clause-level researchinto the semanticsof adverbialsand other
sub-clausalconstituents. We useprior researchon discoursedeixis to study both the semantic
natureof theargumentsof adverbialsandthesyntacticconstituentsfrom whichthey canbederived.
We presenta wide varietyof discourseandclausaladverbials. We show thatdiscourseadverbials
functionsemanticallyasdiscourseconnectivesbecausethey containsemanticargumentsthatmayor
maynotbesyntacticallyovert,but whoseinterpretationrequiresanabstractobjectinterpretationof
acontextual constituent.Weshow thatclausaladverbialsdo not functionsemanticallyasdiscourse
connectivesbecausetheinterpretationsof theirsemanticargumentsdonotrequiretheabstractobject
interpretationof a contextual constituent,althoughthey may make anaphoricreferenceto other
contextual interpretations.Wefurthershow how thepredicateargumentstructureandinterpretation
of discourseadverbialscanbeformalizedandincorporatedinto thesyntaxof theDLTAG model.
It is not only dueto their predicateargumentstructureandinterpretationthat adverbialshave
beenclassifiedasdiscourseconnectives,however. We encounterin our corpusa numberof adver-
bials thathave beentreatedasdiscourseconnectivesdespitethe fact that their semanticsdoesnot
requireabstractobjectinterpretationsin thediscourseor spatio-temporalcontext. Weexploreother
explanationsfor how theseadverbialsevoke discoursecontext duringtheir interpretation;in partic-
3
![Page 21: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/21.jpg)
ular, we investigatethe interactionof their semanticswith othersemanticandpragmaticdevices.
We show how focuseffects in S-modifyingadverbialscontribute to discoursecoherence,andwe
alsoshow how S-modifyingadverbialscanbeusedto convey Griceanimplicatures.
While thesemanticsandpragmaticsdiscussedherewill not provide a completeaccountof the
discoursefunctionsof all adverbials, it will show that the analysisof adverbialscan be viewed
modularly: certain functionscan be attributed to the semanticdomain,othersto the pragmatic
domain,andstill othersto largerissuesof discoursestructure.
Therearenumerousbenefitsof thisanalysis.First, it is economical,makinguseof pre-existing
clause-level mechanismsto build adverbial semanticsat the discourselevel, therebyreducingthe
loadon inferenceto accountfor discourseinterpretation(c.f. [Keh95]). Secondly, it providesa the-
oreticalgroundingfor [Kno96]’s empiricalapproachto studyingthelexical semanticsof discourse
connectives, in the processshowing that additionaladverbialsshouldbe includedin the classhe
isolatesbasedon intuition alone,andthatsomeof thoseincludedtheredon’t reallybelong.Thirdly,
it expandsanexistingmodelof discoursewhicharguesthatdiscoursestructurecanbebuilt directly
on top of clausestructureand therebybridgesthe gap betweenhigh-level discoursetheory and
clause-level theory.
1.3 ThesisOutline
In this chapter, we have givena brief overview of theanalysesthatwe presentin theremainderof
this thesis.Therestof this thesisis organizedasfollows:
In Chapter2 we survey a variety of existing discoursetheoriesandexaminethe similarities
anddifferencesbetweeneachtheory. We discusshow, takentogether, eachtheoryservesto distin-
guishdifferentmodulesrequiredto build a completeinterpretationof discourse.We thenoverview
DLTAG asanotherimportantmodulethataloneout of all theothersis capableof bridgingthegap
betweendiscourselevel theoriesandclauselevel theories,by treatingdiscourseconnectivesaspred-
icatesandusingthesamesyntaxandsemanticsthatbuilds theclauseto build anintermediatelevel
of discourse.
In Chapter3 we investigatethe semanticmechanismsthat causesomeadverbialsto function
4
![Page 22: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/22.jpg)
asdiscourseconnectives. We discussprior researchinto the semanticsof adverbialsandpresent
an analysisof the S-modifying adverbials in the PennTreebankcorpusthat distinguishesthose
adverbialsthat function asdiscourseconnectives accordingto their predicate-argumentstructure
andinterpretation.
In Chapter4 we show how thesemanticsof adverbialsdiscussedin Chapter3 canbeincorpo-
ratedinto a syntaxsemanticinterfacefor DLTAG. We discusssyntax-semanticinterfacesthathave
beenproposedfor clause-level grammarsandrelateddiscoursegrammarsandshow how thesein-
terfacescanbeextendedto DLTAG. We furtherdiscusstheDLTAG annotationprojectwhosegoal
is to annotatetheargumentsof all discourseconnectives,bothstructuralandanaphoric.
In Chapter5 we continueour analysisof how adverbialsfunction as discourseconnectives.
investigatingotherwaysapartfrom their predicateargumentstructureandargumentresolutionin
whichanadverbialcanbeusedto contribute to discoursecoherence.
Weconcludein Chapter6 anddiscussdirectionsfor futurework.
5
![Page 23: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/23.jpg)
Chapter 2
Anaphora and DiscourseModels
2.1 Intr oduction
Discoursemodelsexplain how sequencesof utterancesareput togetherto createa text. Building
a coherent discourseinvolves more than just concatenatingrandomutterances;in addition, the
contributionsof eachutteranceto the surroundingcontext mustbe established.Two major areas
of investigationhave beendistinguished.The first concernshow sub-clausalconstituentsobtain
their meaningthroughrelationshipsto entitiespreviously evoked in a discourse.Suchconstituents
includeNPs, suchasin (2.1) wherethe personalpronounhe refersto an entity mentionedin the
prior sentence,(2.2)wherethebeerrefersto oneof theelementsof thepicnic in theprior sentence,
and(2.3)wherethedemonstrative pronounthat refersto theinterpretationof theprior sentence.
(2.1)Bill talkedto Phillip. He got reallyupset.
(2.2)Bill andMary tookapicnic to thepark.Thebeerwaswarm.
(2.3)Bill talkedto Phillip. Thatmadememad.
OtherexamplesincludeVPs, suchasin (2.4)wheretheelidedVP ( G ) mustbedeterminedfrom
themeaningof theprior sentence,andin (2.5)wheretheuseof simplepasttensein bothsentences
createsanimpressionof forwardprogressionin time.
(2.4)Bill talkedto Phillip. I did G too.
(2.5)Bill entered theroom.He began to talk.
6
![Page 24: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/24.jpg)
The secondmajor areaof investigationconcernshow clausal(andsuper-clausal)constituents
obtain their meaningthroughrelationshipsto clausalconstituentsin the surroundingcontext. To
illustratethenatureof theseinvestigations,considerthediscoursein (2.6).
(2.6a)Lastsummer, theKeatingstraveledin Zimbabwe.
(2.6b) Patstudiedflora in theChimanimanimountains.
In the absenceof any additionalcontext, onereadermight interpret(2.6), and/orthe writer’s
intention in producing(2.6), as a descriptionof what the Keatingson the onehand,andPat on
the other, did the prior summer. Another readermight interpret it as contrastingwhat the two
participantsdid theprior summer, e.g.theKeatings(just) traveled,whereasPatstudied.
Interactionsbetweenthesetwo areasof investigationhave also beenstudied. For example,
suppose(2.6) is precededandfollowedby othersentences,asin (2.7).
(2.7a)PatKeatingmarriedMaria Lopezlastspring.
(2.7b) Lastsummer, theKeatingstraveledin Zimbabwe.
(2.7c) Patstudiedflora in theChimanimanimountains.
(2.7d) Thatwasaspectacularcelebration.
Due to additionof (a), the readerwill likely determinethat Pat is a memberof the Keating
family. S/hemight thus interpretPat’s studyingasan elaborationof, or even asa causeof, the
Keatings’traveling, or s/hemight simply interpretPat’s studyingasoccurringafter the Keatings’
traveling. World knowledgeor inferencemayyield thebelief that theChimanimanimountainsare
locatedin Zimbabwe.Notethatthedemonstrative referencein (d) is hardto resolve to themarriage
describedin (a)unlesswe move it to apositionimmediatelyfollowing (a) in thediscourse.
A completemodelof discoursemustaccountfor all of theserelationships,andtheir interactions.
In particular, adiscoursemodelmustcharacterize:H thepropertiesof theconstituentsthatarebeingrelatedH thetypeof relationshipsthatcanexist betweentheseconstituentsH themechanismsunderlyingtheserelationships
7
![Page 25: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/25.jpg)
H theconstraintson theapplicationof thesemechanisms
In the following sectionswe will survey a variety of existing discoursemodelsin termsof
their coverageof the above characterizations.By taking a roughly chronologicalapproach,and
examiningthe benefitsandlimitations of eachsubsequentmodel in termsof how it incorporates
thoseprior to it, thesecharacterizationswill befleshedout,andit will beshown that,takentogether,
eachtheoryservesto distinguishdifferentmodulesrequiredto build a completeinterpretationof
discourse.We thenintroduceDLTAG asanimportantmodulecapableof bridgingthegapbetween
discourselevel theoriesandclauselevel theories.
2.2 DescriptiveTheoriesof DiscourseCoherence
2.2.1 An Early EncompassingDescription
[HH76] earlyproposedthata singleunderlyingfactor, which they call cohesion, unifiessequences
of sentencestocreateadiscourse.Cohesionis definedasthe“semanticrelationsbetweensuccessive
linguistic devicesin a text, wherebythe interpretationof onepresupposesthe interpretationof the
otherin thesensethatit cannotbeeffectively decodedexceptby recourseto it”([HH76] p.4)1. They
distinguishfiveclassesof cohesion,shown in Figure2.1.
Figure2.1: [HH76]’s Typesof Cohesion
Referenceis asemanticrelationachievedby theuseof acataphoricor anaphoricreferenceitem
to signalthat theappropriateinstantialmeaningbesupplied.Personalreference(signaledby per-
1This useof the term“presupposition”is not equivalentto semanticpresupposition;the latterdependson truth val-uation and the former doesnot. Both [HH76] and [Sil76] define“discourse”,or “pragmatic”, presuppositionas therelationshipof a linguistic form to its prior context; Silversteinaddsthata pragmaticpresuppositionis whata languageusermustknow aboutthecontext of useof a linguistic signalin orderto interpretit [Sil76, 1]. SeeChapter5 for furtherdiscussionof presupposition.
8
![Page 26: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/26.jpg)
sonalpronounsanddeterminers,e.g. I, my), demonstrative reference(signaledby demonstratives,
e.g. this, that), andcomparative reference(signaledby certainnominalmodifiers,e.g. same, and
verbaladjuncts,e.g. identically) aredistinguished,andexemplifiedin italics in (2.8).
(2.8)Johnsaw ablackcat,but that doesn’t meanit wasthesameblackcathesaw before.
Lexical cohesionis a semanticrelation achieved by the successive useof vocabulary items
referringto thesameentity or event, includingdefinitedescriptions,repetitions,synonyms,super-
ordinates,generalnouns,andcollocation.Everylexical itemcanbelexically cohesive; this function
is establishedby referenceto the text. In [HH76]’s example,shown in (2.9), thereare definite
descriptions:a pie...thepie, repetitions:pie...pie, generalnounsandsynonyms: a pie...adaintydish
andsuper-ordinates:blackbirds...birds.
(2.9)
Singasongof sixpence,apocket full of rye,
Four-and-twentyblackbirdsbakedin apie,
Whenthepie wasopened,thebird beganto sing,
Wasn’t thatadaintydishto setbeforeaking?
Substitution andEllipsis aregrammaticalrelations,which canbenominal,verbal,or clausal.
Thesubstitutemustbeof thesamegrammaticalclassastheitemfor whichit substitutes,andellipsis
is substitutionby zero([HH76, 89]). In (2.10),nominaloneis a substitute,andthereis ellipsisof
theembeddedpredicatein thefinal clause.
(2.10)Mary covetstwo things. Her money will be thefirst oneto leave her. Her husbandwill
bethenext 0.
Conjunction is asemanticrelationusuallyachievedby theuseof conjunctive elements,whose
meaningpresupposesthepresenceof otherpropositionsin thediscourseandspecifiestheway they
connectto the propositionthat follows. Italicized examplesareshown in (2.11). [HH76] distin-
guishfour main typesof relationsbetweenpropositions,shown in Table2.1. Theserelationsare
furthersubdivided,andanorthogonaldistinctionis madebetweenexternal and internal relations;
the formerhold betweenelementsin theworld (referredto in thetext), andthe latterbetweentext
elementsthemselves,suchasspeechacts.
9
![Page 27: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/27.jpg)
(2.11)Becauseit snowedheavily, thebattlewasnot fought,so thesoldierswenthome.
Table2.1: Main Categoriesof [HH76]’sRelationsbetweenPropositions
ADDITIVE ADVERSATIVE CAUSAL TEMPORALcomplex contrastive specific sequentialapposition correction conditional simultaneouscomparison dismissal respective conclusive
correlative
2.2.2 Alter nativeDescriptionsof PropositionalRelations
In comparisonto [HH76], [Lon83]’s studyof discoursecoherencedistinguishesbetweenpredica-
tions expressedby clauses,which he modelswith predicatecalculus,and relationson the pred-
icationsexpressedby clauses,which he characterizesinto two main types,shown in Table 2.2:
the “basic” operationsof propositionalcalculus,supplementedby temporalrelations,anda setof
elaborative relations.Theserelationsarefurthersubdivided,andanorthogonaldistinctionis made
betweennon-frustratedandfrustratedrelations,thelatterbeingthecasewhenanexpectedrelation
is not satisfiedby theassertionsin thetext. Unlike [HH76], [Lon83] doesnot emphasizea correla-
tion betweentheserelationsandsurfacesignalsin thetext; rather, they aremeantto categorizethe
“deep” relationsunderlyingthesurfacestructureof discourse.
Table2.2: Main Categoriesof [Lon83]’s RelationsbetweenPropositions
BASIC ELABORATIVEconjoining( I ) paraphrasealternation( J ) illustrationimplication( K ) deixistemporal attribution
Morerecently, [Mar92] hasproposedanalternativesetof relationsbetweenpropositions,shown
in Table2.3,in whichfour maintypesaredistinguished.Theserelationsarefurthersubdivided,and
orthogonaldistinctionsaremadebetweeninternalandexternalrelations,andparatactic,hypotactic,
andneutral relations.Thefirst dimensionis taken from [HH76], andthe latterdimensionroughly
10
![Page 28: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/28.jpg)
correspondsto coordinating,subordinating,andvariablycoordinatingandsubordinatingrelations,
respectively. Like [HH76], Martin usesexplicit signalsto derive his set of discourserelations,
but like [Lon83], he defendstheclaim that they represent“deep” relationsunderlyingthesurface
structure.He combinesthe two approachesby usingan insertiontest: a “deep” relationexists at
a placein thetext if anexplicit signalcanbe insertedthere.Nevertheless,his setis differentfrom
both[HH76] and[Lon83].
Table2.3: Main Categoriesof [Mar92]’sRelationsbetweenPropositions
ADDITIVE COMPARATIVE TEMPORAL CONSEQUENTIALaddition similarity simultaneous purpose concessionalternation contrast successive condition manner
consequence
[SSN93] take a psychologicalapproach,identifying the basiccognitive resourcesunderlying
theproductionof discourserelations.Four cognitive primitivesareidentified,accordingto which
discourserelationscanbeclassified,which they exemplify usingexplicit cuephrases.[SSN93]cite
anumberof psychologicalexperimentsto supportthesefeatures.H basicoperation: Eachrelationcreateseitheranadditive (and) or acausal(because) connec-
tion betweentherelatedconstituents.H source of coherence: Eachrelationcreateseithersemanticor pragmaticcoherence;in the
first casethepropositionalcontentof theconstituentsis related,in thesecondcasetheillocu-
tionaryforceof theconstituentsis related.H order of segments: Causalrelationsmayhave thecausingsegmentto theleft or theright of
theresult.H polarity : A relationis negative if it links thecontentof onesegmentto thenegationof the
contentof theothersegment(although), andpositive otherwise.
[Hob90] takesa computationalapproach,identifying relationsbetweenpropositionsaccording
to thekind of inferencethatis requiredto identify them.Themaincategoriesareshown in Table2.4.
11
![Page 29: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/29.jpg)
Respectively, thesecategoriesdistinguishinferenceaboutcausalitybetweeneventsin the world,
inferenceaboutthespeaker’s goals,inferenceaboutwhat theheareralreadyknows, andinference
thata heareris expectedto be ableto make aboutrelationshipsbetweenobjectsandpredicatesin
theworld. [Hob90] suggeststhat inferenceshouldbeviewedasa recursive mechanism;whentwo
propositionsare linked by a relation, they form a unit which itself canbe relatedto otherunits,
therebybuilding aninterpretationof thediscourseasawhole.
Table2.4: Main Categoriesof [Hob90]’s RelationsbetweenPropositions
Occasion Evaluation Ground-Figure Explanationcause background parallel generalizationenablement explanation exemplification contrast
2.2.3 DiscourseRelationsasConstraints
[Keh95] reformulates[Hob90]’s relationsbetweenpropositionsinto threemaintypesof moregen-
eral “discourserelations”: Contiguity, Cause-Effect, andResemblance,which hedefinesin terms
of constraintsonbothclausalandsub-clausalpropertiesof discourseunitsSL andSM . Hethenspec-
ifies how an inferencemechanismcanbeusedto derive Cause-Effect andResemblancerelations,
andshows how they interactwith sub-clausalcoherence.Like [HH76] and[Mar92], hecorrelates
theserelationswith the presenceof cuephrases,suggestingthat they could be treatedasbearing
semanticfeaturesthatinteractwith thediscourseinferenceprocess.
Narration is theonly ContiguityrelationKehlerdefines.Exemplifiedin (2.12),theconstraint
on its derivation is that a changeof statefor a systemof entitiesfrom SM be inferred,wherethe
initial statefor this systemis inferredfrom SL .(2.12)Bill pickedup thespeech.Hebeganto read.
Kehlernotesthat the full setof constraintsgoverning the recognitionof a Narrationrelation
arenotwell understood,but herefutes([HH76, Lon83])’s treatments,whichequateit with temporal
progression,citing [Hob90]’sexample(2.13),whoseinterpretationrequirestheadditionalinference
thatBushis on thetrain,or thatthetrainarrival is somehow relevantto him.
12
![Page 30: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/30.jpg)
(2.13)At 5:00a trainarrivedin Chicago.At 6:00GeorgeBushheldapressconference.
Kehlerdistinguishesfour typesof Cause-Effectrelations,all of which mustsatisfy the con-
straintthat a presupposedpathof implicationbe inferredbetweena propositionP from SL , anda
propositionQ from SM . Eachtypeandtheimplicationit requiresis shown in Table2.5,alongwith
correlatedcuephrases.
Table2.5: [Keh95]’s Cause-Effect Relations
Relation Presupposition ConjunctionsResult P K Q asa result,therefore,and
Explanation Q K P becauseViolatedExpectation P KON Q butDenialof Preventer Q KON P despite,eventhough
To take two examples,aResult relationis inferredwhenQ is recognizedasnormallyfollowing
from P. In (2.14),beinga politician normallyimpliesbeingdishonest.
(2.14)Bill is apolitician,andthereforehe’s dishonest.
Denial of Preventer relationsareinferredwhen N P is recognizedasnormally following from
Q (example(2.15)).
(2.15)Bill is honesteventhoughhe’s apolitician.
Kehlerdistinguishessix typesof Resemblancerelations,all having theconstraintthata com-
monor contrastingrelationP beinferredbetweenSL andSM , suchthat P subsumespL andp M , where
pL appliesover a setof entitiesaM ,...a� from SL , andp M appliesover a setof entitiesb M ,...b� from
SM . CertainResemblancerelationsalsohave theconstraintthatapropertyvector Q beinferred,such
that Q consistsof commonor contrastingpropertiesq� , which hold for a� andb� , for all + 2. Table
2.6providestheconstraintsfor eachResemblancerelationandits correlatedcuephrase.
For example,Exemplification holdsbetweena generalstatementfollowed by an exampleof
the generalization.In (2.16),aM andb M correspondto themeaningsof youngaspiring politicians
2KehlernotesthatElaborationrelationsarea limiting caseof Parallel relations,wherethesimilar entitiesaR andbRareidentical.
13
![Page 31: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/31.jpg)
and SUT7VXW ; while pL andp M correspondto themeaningsof supportandcampaignfor respectively3.
Generalization is identicalto Exemplification,exceptthattheorderof theclausesis reversed.
(2.16)Youngaspiringpoliticiansoftensupporttheirparty’spresidentialcandidate.For instance,
Johncampaignedhardfor Clinton in 1992.
Table2.6: [Keh95]’sResemblanceRelations
Relation Constraints ConjunctionsElaboration pL = p M , a� = b� in otherwords
Exemplification pL = p M , b�UY a� or b�UZ a� for exampleGeneralization pL = p M , a� Y b� or a� Z b� in general
Parallel pL = p M , q� (a� ) andq� (b� ) andContrast(i) pL = N p M , q� (a� ) andq� (b� ) butContrast(ii) pL = p M , q� (a� ) and N q� (b� ) but
Parallel relationsrequiretherelationsexpressedby thesentenceandthecorrespondingentities
to be recognizedassharinga commonproperty. In (2.17),pL andp M correspondto the meanings
of organizedrallies for anddistributedpamphletsfor respectively; P correspondsto the meaning
of do somethingto support. aM andbM correspondto the meaningsof John andBill , which share
the commonpropertyq M that they arepeoplerelevant to the conversation.Contrast relationsre-
quireeithertherelationsexpressedby thesentences(example(2.18))or thecorrespondingentities
(example(2.19))to berecognizedascontrasting.
(2.17)Johnorganizedralliesfor Clinton,andFreddistributedpamphletsfor him.
(2.18)JohnsupportedClinton,but Mary opposedhim.
(2.19)JohnsupportedClinton,but Mary supportedBush.
2.2.4 Abducing DiscourseRelationsby Applying the Constraints
Kehler’s constraintsareformulatedin termsof two operationsfrom artificial intelligence:(1) iden-
tifying commonancestorsof setsof objectswith respectto a semantichierarchy(Resemblance
3Although not discussedby Kehler, the subsumingproperty[ is equatablewith p\ , andp ] canbe recognizedasamemberof p\ .
14
![Page 32: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/32.jpg)
relations),and(2) computingimplication relationshipswith respectto a knowledgebase(Cause-
Effectsrelations).Kehlerdistinguishestwo stepsin thediscourseinferenceprocess:
(a) Identify andretrieve theargumentsto thediscourserelation
This stepis achieved via the sentenceinterpretation;Kehlerusesa formalism relatedto the
versionof Categorial Semanticsdescribedin [Per90], in which sentenceinterpretationresultsin a
syntacticstructureannotatedwith thesemanticrepresentationof eachconstituent.Thesesemantic
representationsareargumentsto thediscourserelation,andareidentifiedandretrievedvia theircor-
respondingsyntacticnodes.Cause-Effect relationsrequireonly theidentificationof thesentential-
level semanticsfor the clausesasa whole (i.e. P andQ). Resemblancerelationsrequirethat the
semanticsof sub-clausalconstituentsbeaccessed,in orderto identify pL andp M , anda� andb� .(b) Apply theconstraintsof therelationto thosearguments
Thesecondstep,Kehlersuggests,couldbeachievedfor Resemblancerelationsusingcompari-
sonandgeneralizationoperationssuchasproposedin [Hob90] andelsewhere,while [HSAM93]’s
logical abductioninterpretationmethodcouldbeusedto abducethepresuppositionfor theCause-
Effect relations.[HSAM93]’s methodcouldfurtherdeterminewith whatdegreeof plausibility the
constraintsaresatisfiedsuchthataparticularrelationholds.
In [HSAM93]’s framework, discourserelationsbetweendiscourseunits areproved (abduced)
usingworld anddomainknowledge,via aprocedureof axiomapplication.Eachdiscourseunit is a(�.�^`_a.�Wcb , asdefinedby axiom(2.20),whereif ( is a sentencecontaininga stringof words, d , and. is its assertionor topic, thenit is adiscoursesegment.
(2.20)( e w, e)s(w, e) f Segment(w, e)
Whenadiscourserelationholdsbetweentwo segments,theresultingstructureis alsoasegment,
yielding a hierarchicaldiscoursestructure,ascapturedby axiom (2.21),whereif w M andw g are
segmentswhoseassertionor topic arerespectively eM andeg , anda discourse(coherence)relation
holdsbetweenthecontentof w M andw g , thenthestringw M w g is alsoasegment.Theargument. of
CoherenceRelis theassertionor topicof thecomposedsegment,asdeterminedby thedefinitionof
thediscourserelation.
15
![Page 33: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/33.jpg)
(2.21) (e w M , w g , eM , eg , e) Segment(wM , eM ) J Segment(wg , eg ) J CoherenceRel(eM , eg , e) fSegment(wM w g , e)
To interpretadiscourseW, therefore,onemustprove theexpression:
(2.22)( h e)Segment(W, e)
Weuseasanexampleavariantof thatfoundin [Keh95]:
(2.23)Johnis dishonest.He’sapolitician.
To interpretthis discourse,it mustbe proven a segment,by establishingthe threepremisesin
axiom (2.21). The first two premisesareestablishedby (2.20), it thereforeremainsto establish
a discourserelation. BecauseExplanationis a defineddiscourserelation,we have the following
axiom:
(2.24)( e eM , eg )Explanation(eM , eg ) f CoherenceRel(eM , eg , eM )In explanations,Hobbsnotes,it is thefirst segmentthatis explained;thereforeit is thedominant
segmentandits assertion,eM , will betheassertionof thecomposedsegment,i.e. thethird argument
of CoherenceRelin (2.24).
Recall that the constraintsdefinedby Kehler on Explanationrelationswere that Q K P be
presupposed;in Hobbs’ terms,thepresuppositioni8j/k$(�. (eM , eg ) mustbeabduced,asexpressedby
thefollowing axiom:
(e eM , eg )cause(eM , eg ) f Explanation(eM , eg )In otherwords,to abduceanExplanationrelation,whatis assertedby eg mustprovento bethe
causeof eM . In [HSAM93], utterances,like discourserelations,areinterpretedby abducingtheir
logical form, usingaxiomsthat arealreadyin the knowledgebase,arederivable from axiomsin
the knowledgebase,or canbe assumedat a costcorrespondingto somemeasureof plausibility.
Assumewehave abducedthefollowing axiom:
(2.25)( e x, eM )Politician(eM , x) f ( h eg )Dishonest(eg , x) J cause(eM , eg )Thatis, if eM isastateof x beingapolitician,thenthatwill causethestateeg of x beingdishonest.
Theplausibility measurethat is assignedto this formulawill beinverselyproportionateto thecost
16
![Page 34: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/34.jpg)
assignedto anExplanationrelation.Assuming(2.25)hasahighplausibility in ourknowledgebase,
then in the logical forms of the two sentencesin (2.23), John (andhe) canbe identifiedwith x,
cause(eM , eg ) proventhereby, andExplanationwill beviewedasthelikely relationbetweenthetwo
sentences4.
2.2.5 Interaction of DiscourseInferenceand VP Ellipsis
[Keh95] shows how thediscourseinferenceprocessfor Resemblancerelationsinteractsdifferently
thanthediscourseinferenceprocessfor Cause-Effect relationswith VP ellipsis,basedon thedif-
ferentconstraintsthey requireto besatisfiedby theclausesthey areinferredbetween.In particular,
the argumentsto Resemblancerelationsaresetsof parallelentitiesandrelations. Therefore,the
discourseinferenceprocessmustaccesssub-clausalconstituentsin identifyingandretrieving those
arguments,including the missingconstituentin VP ellipsis. In contrast,the argumentsto Cause-
Effect relationsarepropositions.Thereforetheinferenceprocessneednot accesssub-clausalcon-
stituents.Thisdifferenceaccountsfor differentfelicity judgmentsconcerningVP ellipsisdisplayed
acrossthetwo typesof relations.
To exemplify his analysis,considerexample(2.26),in which a Parallelrelationcanbeinferred
betweenthetwo clauses:
(2.26)Bill becameupset,andHillary did too.
ToestablishaParallelrelation(seetheResemblanceRelationdefinitionsin Table2.6),p(aM ,ag ...)mustbeinferredfrom Sl , andp(bM ,bg ...) mustbeinferredfrom Sm , wherefor somepropertyvectorQ , q� (a� ) andq� (b� ), for all + . Theidentificationof theseargumentsrequirestheelidedmaterialto be
recovered j`WU- reconstructedin theelidedVP (see[Keh95] for detailsof theprocessof reconstruc-
tion). Compare(2.26),however, with (2.27).
(2.27)*The problemwaslookedinto by Billy, andHillary did too.
Again,to establishaParallelrelationbetweenthetwo clauses,theargumentsmustbeidentified,
requiringtheelidedmaterialto berecoveredandreconstructedin theelidedVP. But in thiscasethe
4This explanationis from [Keh95, 18] and[Lag98]. See[HSAM93] for furtherdetails
17
![Page 35: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/35.jpg)
recovery of waslooked into createsa mismatchof syntacticform whenit is reconstructedin the
elidedVP, resultingin aninfelicitousdiscourse.
Suchinfelicity doesnot occur, however, when thereis a Cause-Effect relation betweentwo
similar clauses,asin example(2.28):
(2.28)Theproblemwasto have beenlookedinto, but obviously nobodydid.
KehlerarguesthatbecauseestablishingaViolationof Expectationrelation(seetheCause-Effect
Relationdefinitionsin Table2.5)requiresonly thatapropositionPbeinferredfrom Sl , andapropo-
sition Q be inferredfrom Sm (wherenormallyP KnN Q), theelidedVP neednot bereconstructed
in thesyntax,but canberecoveredthroughanaphoraresolution.Theresultis that thediscourseis
felicitous5.
2.2.6 Summary
In this section,we have seentheearlydelineationof differenttypesof coherenceproposedby Hal-
liday andHasanreflectedin subsequenttheoriesof discoursecoherence,which we will seefurther
below. Thecomparisonof thesetof propositionalrelationsproposedby Halliday andHasanwith
thoseproposedin otherdescriptive theorieshighlightsthelack of agreementin theliteratureabout
how animportantaspectof discoursecoherenceshouldbedescribed.As we will continueto seein
the following sections,thoughmostmodelsmake useof explicit signalsto characterizediscourse
relations,therestill existsconsiderablevariationin thenumberandtypeof discourserelationseach
modeldefines.Whatdistinguisheseachmodelis thedegreeandmannerwith which they associate
theirpostulatedsetof discourserelationsto mechanismsthatproducethemandhow they constraint
theapplicationof thesemechanisms.Kehler’s attemptto definerelationsbetweendiscourseunits
in termsof constraintswhich thoseunitsmustsatisfy, to demonstratehow their satisfactioncanbe
determinedusingthe logical abductionmethodof Hobbset al., andto show how this satisfaction
interactswith sub-clausalcoherence,is a first exemplificationof suchanassociation.We will see
othersbelow, andin thefinal sectionwe will seea way in which thesevariousapproachescanbe
5Kehlerdoesnotaddressthefactthat(2.26)is infelicitouswith a Cause-Effect relation,e.g.Theproblemwaslookedinto byBilly, but Hillary didn’t.
18
![Page 36: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/36.jpg)
simplified.
2.3 A Thr ee-Tiered Model of Discourse
2.3.1 The ThreeTiers
[GS86]presenta theoryof discoursethatdistinguishesthreeinteractingcomponents:thelinguistic
structure,theintentionalstructure,andtheattentionalstate.
The linguistic structure representsthestructureof sequencesof utterances,i.e. thestructure
of segmentsinto which utterancesaggregate. This structureis not strictly compositional,because
a segmentmay consistof embeddedsubsegmentsaswell asutterancesnot in thosesubsegments.
This structureis viewedasakin to thesyntacticstructureof individual sentences([GS86],footnote
1), althoughtheboundariesof discoursesegmentsareharderto distinguish6.
The intentional structure representsthe structureof purposes,(DSPs),i.e. the functionsof
eachdiscoursesegment,whosefulfillment leadsto the fulfillment of anoverall discoursepurpose
(DP).DPsandDSPsaredistinguishedfrom otherintentionsby thefactthatthey areintendedto be
recognized.Non-DP/DSPintentions,suchasa speaker’s intentionto usecertainwords,or impress
or teachthehearer, areprivate, i.e. not intendedto contributeto discourseinterpretation.Examples
of DPsandDSPsinclude intendingthe hearer to performsomeaction, intendingthe hearer to
believe somefact, intendingthe hearer identify someobject or property of an object. As these
examplesimply, thesetof intentionsthatcanserveasDSPsandDPsis infinite, althoughit remains
anopenquestionof whetherthereis afinite descriptionof thisset.However, [GS86] arguethatthere
areonly two structuralrelationswhich canhold betweenDSPsandtheir correspondingdiscourse
segments.If thefulfillment of a DSPA providespartial fulfillment of a DSPB, thenB dominates
A. If a DSPA mustbefulfilled beforea DSPB, thenA satisfaction-precedesB. Becausea hearer
cannotknow the whole setof intentionsthat might serve asDSPs,what they recognize,[GS86]
argue,is therelevantstructuralrelationsbetweenthem.
Theattentional state is viewedasa componentof thecognitive state, which alsoincludesthe
6See[GS86,FM02] for referencesto studiesinvestigatingtheseboundaries.
19
![Page 37: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/37.jpg)
knowledge,beliefs,desiresandprivateintentionsof thespeaker andhearers.Theattentionalstate
is inherentlydynamic,andis modeledby a stackof focusspaces, eachconsistingof the objects,
propertiesand relationsthat are salientin eachDSP, as well as the DSP itself. Changesin the
attentionalstatearisethroughtherecognitionof thestructuralrelationsbetweenDSPs.In general,
whentheDSPfor a new discoursesegmentcontributesto theDSPfor the immediatelypreceding
segment,it will bepushedontothestack;whenthenew DSPcontributesto someintentionhigher
in the dominancehierarchy, several focusspacesarepoppedfrom the stackbeforethe new one
is pushed. Onerole of the stackis to constrainthe possibleDSPsconsideredas candidatesfor
structuralrelationswith theincomingDSP;only DSPsin thestackandin oneof thetwo structural
relationsareavailable. Another role of the stackis to constrainthe hearer’s searchfor possible
referentsof referringexpressionsin anincomingutterance;thefocusspacecontainingtheutterance
will provide themostsalientreferents.Figure2.2 illustratesthemajoraspectsof themodel.
Figure2.2: Illustrationof [GS86]’sDiscourseModel
In the left of thefigure,a sequenceof five utterancesis divided into DSs,whereDS1includes
bothDS2andDS3,aswell asUtterance1andUtterance5,which arenot includedin eitherDS2or
DS3.As shown in (a),thefocusspaceFS1containingDSP1andtheobjects,propertiesandrelations
so far identifiedin DS1 is pushedon the stack. BecauseDSP1is identifiedasdominatingDSP2,
FS2 is alsopushedonto the stack. In (b), DSP2is identifiedasbeing in a satisfaction-precedes
relationshipwith DSP3;FS2is thuspoppedfrom thestackbeforeFS3is pushedontothestack.
[GS86] argue that the hearermakesuseof threepiecesof informationwhendeterminingthe
20
![Page 38: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/38.jpg)
segments,their DSPs,andthestructuralrelationshipsbetweenthem. First, linguistic expressions,
including cue phrasesand referring expressionsas well as intonationand changesin tenseand
aspect,areviewed as primary indicatorsof discoursestructure,even as the attentionalstructure
constrainstheir interpretations.[GS86]arguethatwhile linguisticexpressionscannotindicatewhat
intentionis enteringinto focus,they canprovide partial informationaboutchangesin attentional
states,whetherthischangereturnsto apreviousfocusspaceor createsanew one,how theintention
in thecontainingdiscoursesegmentis relatedto otherintentions,andstructuralrelationsbetween
segments.They exemplify suchusesof linguisticexpressionasshown in Table2.7.
Table2.7: [GS86]Changesin DiscourseStructureIndicatedby LinguisticExpressions
AttentionalChange (push) now, next, thatremindsme,and,but(popto) anyway, but anyway, in any case,now backto(complete) theend,ok, fine,paragraphbreak
TrueInterruption I mustinterrupt,excusemeFlashbacks Oops,I forgotDigressions By theway, incidentally, speakingof
Did youhearabout...,thatremindsmeSatisfaction-precedes in thefirst place,first, second,finally
moreover, furthermoreNew Dominance for example,to wit, first, second,and
moreover, furthermore,therefore,finally
Second,thehearermakesuseof theutterance-level intentionsof eachutterance[Gri89] to de-
terminethe DSPof eachdiscoursesegment. The DSPmay be identical to someutterance-level
intentionin a segment,asin a rhetoricalquestion,whoseintentionis to causethehearerto believe
thepropositionconveyed in thequestion.Alternatively, theDSPmaybesomecombinationof the
utterance-level intentions,asin asetof instructions,wheretheintentionof thespeaker is thatall of
thembecompleted.
Third, sharedknowledgebetweenthe speaker andheareraboutthe objectsandactionsin the
stackcan help determinethe structuralrelationsbetweenutterancesand the intentionsunderly-
ing them. [GS86] proposetwo relationshipsconcerningobjectsandactionsthata heareruses.A
supports relationholding betweenpropositionsmay indicatedominancein onedirection,while
21
![Page 39: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/39.jpg)
a generatesrelationholding betweenpropositionsmay indicatedominancein anotherdirection.
They leaveasanopenquestionhow theserelationsbetweenobjectsarecomputed,but view themas
morebasicversionsof thepossiblerelationsbetweenpropositionsproposedby [HH76] andothers.
Together, this informationenableahearerto reasonout theDSPsandDP in adiscourse.
2.3.2 Coherencewithin DiscourseSegments
Within eachdiscoursesegment,CenteringTheory(CT) [WJP81] is amodelof sub-clausaldiscourse
coherencewhichtracksto themovementof entitiesthrougheachfocusstateby oneof four possible
focusshifts. In CT, eachdiscoursesegmentconsistsof utterancesdesignatedasU � . Eachutterance
U � evokesa (�.�b of discourseentities,the forward-looking centers,Cb(U � ). The highest-ranked
entity in Cf(U �,D M ) that is op.�jq)r+#s`.�- in U � is thebackward-looking center, Cb. Thehighest-ranked
entity in Cf(U � ) is thepreferred center, Cp. Therealizerelationis definedin [WJP81] asfollows:
As utteranceU realizesa center i if i is an elementof the situationdescribedby U, or i is the
semanticinterpretationof somesubpartof U.
Rankingof themembersof theCf list is language-specific;in Englishtherankingis asfollows:
Subjectt IndirectObject t DirectObject t Other
Four typesof transitionsaredefinedto reflectvariationsin the degreeof topic continuity and
arecomputedaccordingto Table2.8:
Table2.8: CenteringTheoryTransitions
Cb(U� ) = Cb(U�,D M ) Cb(U� ) uv Cb(U�,D M )Cb(U� ) = Cp(U� ) Continue Smooth-ShiftCb(U� ) uv Cp(U� ) Retain Rough-Shift
Discoursecoherenceis thencomputedaccordingto thefollowing transitionorderingrule: Con-
tinueis preferredto Retain,which is preferredto Smooth-Shift,which is preferredto RoughShift.
CT modelsdiscourseprocessingfactorsthatexplain thedifferencein theperceived coherence
of discoursessuchas(2.29)and(2.30).
22
![Page 40: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/40.jpg)
(2.29a)Jeff helpedDick washthecar.
(2.29b)He washedthewindows asDick waxedthecar.
(2.29c)He soapedapane.
(2.30a)Jeff helpedDick washthecar.
(2.30b)He washedthewindows asDick waxedthecar.
(2.30c)He buffed thehood.
CT predictsthat (2.30) is harderto processthan(2.29), becausethoughinitially in both dis-
coursestheentity realizedby Jeff is establishedastheCb,utterance(2.30c)causesa Smooth-Shift
in whichtheCbbecomestheentityrealizedby Dick, becausetheverbbuffing is asubsetof thewax-
ing event.Thepredictedpreferencefor aContinue(whichactuallyoccursin (2.29c))meansthatthe
hearerfirst interpretsthepronounshein (2.30c)astheCp(U�,D M ) andthenrevisesthis interpretation.
2.3.3 Modeling Linguistic Structure and Attentional Stateasa Tree
[Web91] arguesthata treestructureandinsertionalgorithmcanserve asa formal analogueof both
on-linerecognitionof discoursestructureandchangesin attentionstate,therebyremoving theneed
to postulateaseparatestackfor focusspaces,while retainingthedistinctionbetweentext structure,
intentionalstructure,andattentionalstate.
Webber’s modelassumesa one-to-onemappingbetweendiscoursesegmentsand treenodes,
with a clauseconstitutingtheminimal unit. In this way thelinguistic structureis representedcom-
positionally. Eachnodein thetreeis associatedwith theentities,propertiesandrelationsconveyed
by thediscoursesegmentit represents.Whentheinformationin anew clauseC is to beincorporated
into an existing discoursesegmentDS, C is incorporatedinto the treeby the operationof attach-
ment, which addstheC nodeasa child of theDS node,andaddstheinformationconveyedby C to
theDSnode.Thisoperationis illustratedin Figure2.3. (a)shows thetreebeforenode3 is attached,
while (b) shows thetreeafternode3 is attached.Notethat theinformationassociatedwith node3
is representedin node3 and incorporatedinto thediscoursesegment(1,2,3)it hasattachedto.
Whenthe informationin a new clauseC is combinedwith the informationin an existing dis-
coursesegmentto composea new discoursesegmentDS, C is incorporatedinto the treeby the
23
![Page 41: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/41.jpg)
Figure2.3: Illustrationof [Web91]’s AttachmentOperation
operationof adjunction, which makesC andDS thechildrenof a new node,andaddstheinforma-
tion conveyedby C andDS to thenew node.This operationis illustratedin Figure2.4. (a) shows
thetreebeforenode3 is adjoined,while (b) shows thetreeafternode3 is adjoined.Note that the
informationassociatedwith node3 is incorporatedalongwith theinformationassociatedwith node
(1,2) (whichwasalsocreatedby adjunction)into thenew node(1,2),3).
Figure2.4: Illustrationof [Web91]’s AdjunctionOperation
Bothof theseoperationsarerestrictedto applyingto nodesontheright frontierof thediscourse
tree.Formally, theright frontier is thesmallestsetof nodescontainingtheroot suchthatwhenever
anodeis in theright frontier, sois its rightmostchild. In thisway, thetreenodesappearin thesame
linearorderasthecorrespondingsegmentsin thetext.
In Webber’s model, the treereplaces[GS86]’s linguistic structure,andthe right fr ontier re-
places[GS86]’s attentionalstate,i.e. the informationin eachnodeon theright frontier represents
the informationin eachfocusspacein thestack. Becausethemodelis strictly compositional,not
24
![Page 42: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/42.jpg)
all nodes(discoursesegments)in thetreewill containdiscoursesegmentpurposes(DSPs)(e.g.Ut-
terance1andUtterance5in Figure2.2);however, all nodeson theright frontier exceptpossiblythe
leafwill containDSPsthatcontributeto theDPof theoverall discourse(whichwill becontainedin
therootof thetree.)
2.3.4 Intr oduction to DiscourseDeictic Reference
[Lak74] first usedtheterm“discoursedeixis” to referto usesof thedemonstrative likethosein (2.31)
- (2.33),wheretheantecedentof thedemonstrative canbethe interpretationof a verbalpredicates
(2.31),theinterpretationof aclause(2.32),or theinterpretationsof morethanoneclause(2.33).
(2.31)John[smiled]. He doesthat often.
(2.32)[Johntook Biology 101.] Thatmeanshecantake Biology 102.
(2.33)[I wokeupandbrushedmy teeth.I wentdownstairsandatebreakfast,andthenI wentto
work.] That’s all I did today.
Earlystudiesof thisphenomenarelateit to anotheruseof demonstrativesshown in (2.34),where
theantecedentis not in thediscourseat all, but ratherin thespatio-temporalsituation.This useis
called“deictic”, aGreektermmeaning‘pointing’ or ‘indicating’.
(2.34)“Aw, that’s nice,Billy!”, youexclaim,whenyour two-yearold kissesyou.
In [Lyo77]’s view, discoursedeixisachieveshigher-orderreference,wherefirst-orderreference
is definedas referenceto NPs, and higher-order referenceis definedas referenceto larger con-
stituentsinterpretedas events,propositionsand concepts. [Web91] distinguishesfive discourse
deixis interpretations,shown in Table2.9, andexemplifiedin thesecondcolumn,wherefor illus-
trative purposesthediscoursedeicticshouldbeassumedto refer to an interpretationof theclause
“Johntalksloudly”.
Demonstrativesaremostcommonlyemployedin Englishfor discoursedeixispurposes.Corpus
studies,however, have shown thezero-pronounusedin Italian [DiE89] andGerman[Eck98], and
occasionallyin Englishspeech.
[Sch85] studiesroughly 2000 tokensof it and that, andfinds that it is much lessfrequently
25
![Page 43: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/43.jpg)
Table2.9: [Web91]’s Classificationof DiscourseDeictic Reference
Inter pretation Examplehlinespeechact that’s a lieproposition that’s trueevent that happenedyesterdaypuretextual repeatthatdescription that’s a gooddescription
usedthanthat asa discoursedeictic,andthatwhenusesof discoursedeictic it do occur, they are
frequentlyusedaftera discoursedeicticuseof that, in whatSchiffmancallsa “PronounChain”. A
similarobservationis madeby [Web88]. [GHZ93] notemoregenerallythetendency for it to prefer
referenceto focuseditems,while demonstrative pronounspreferreferenceto activateditems. For
example,in (2.35),Both usesof it refer to “becominga streetperson”;by the secondreference,
thispropertyis focused.thatprefersreferringto “becomingastreetpersonwouldhurthismother”,
which is not yet focused,andis highly dispreferredasthereferentfor thesecondit.
(2.35)Johnthoughtaboutbecomingastreetperson.It would hurt his motherandit/that would
make his fatherfurious.
Theoft-citedexamplein (2.36)shows what [GC00] and[Byr00] relatedlyclaim, thatpersonal
pronounstendto refer to entitiesdenotedby nounphrases,while demonstrativestendto referdis-
coursedeictically. In (2.36),thereferentof it is clearly“x”, while thereferentof that is clearlythe
resultof “add x to y”.
(2.36)Add x to y andthenaddit/that to z.
Thepreferenceof it to referto entitiesdenotedby nounphrasesandto referto abstractobjects
only afterthey arereferredto by ademonstrativesuggeststhatnounsaremoresalientthanverbsand
clausesasentities.[Byr00] however, notesthat thesalienceeffectson personalpronounresolution
canbe affectedby what shecalls “SemanticEnhancement”:with enoughpredicateinformation
gearedtowardahigherorderreferent,personalpronounscanmadeto preferhigherorderreferents,
26
![Page 44: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/44.jpg)
asshown in (2.38c).
(2.37)Therewasasnake on my desk.
(2.38a)It scaredme.
(2.38b)Thatscaredme.
(2.38c)I never thoughtit wouldhappento me.(Sem.Enh)
[Eck98] notesa furtherdifferencebetweenthe resolutionof demonstrativesandpersonalpro-
nounsasdiscoursedeixis,which may indicatethat topicsaremoresalientthanverbsandclauses
asentities. In (2.39), that prefersreferenceto thespecificstory describedby Speaker A, while it
prefersreferenceto thetopic of child-carein general7. In fact,[ES99]doesnot considerthisuseof
it adiscoursedeicticuseatall; they treatit asa “vaguepronoun”.
(2.39)
Speaker A: Shehasa privatebaby-sitter. And, uh, thebabyjust screams.I
mean,thebabyis like seventeenmonthsandshejust screams.
Evenif sheknows thatthey’re gettingreadyto go out. They
haven’t evenleft yet...
Speaker B: Yeah,it/that’s hard.
[Lad66] andothersnotesubtlesaliencedifferencesbetweenthe discoursedeictic usesof this
andthat, relatedto theirspatio-temporaldifferences:this is usedwhenthereferentis close, andthat
is usedwhenthereferentis far.
2.3.5 Retrieving Antecedentsof DiscourseDeixis fr om the Tree
Many researchersfind thatdiscoursedeicticreferenceis dependenton discoursestructure.[Pas91]
uses(2.40)to show thattheclausalreferentof adiscoursedeicticis only availableif it immediately
precedesthedeictic. In (d), that cannotreferto sentence(a) unless(b) and(c) areremoved.
(2.40a)Carolinsistsonsewing herdressesform all naturalmaterials
(2.40b)andshewon’t evenconsidersyntheticlining.
(2.40c)Sheshouldtry thenew rayonchallis.
(2.40d)*That’s becauseshe’s allergic to synthetics.
7[GC00] alsoclaim thatprosodyplaysa role in resolvingdiscoursedeicticthat morethanit.
27
![Page 45: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/45.jpg)
[Web91] arguesmore formally that though deictic referenceis often ambiguous(or under-
specified[Pas91]), thereferentis restrictedto theright frontier of thegrowing discoursetree. She
exemplifiesthisusing(2.41)-(2.42):
(2.41a)It’s alwaysbeenpresumedthat
(2.41b)whentheglaciersreceded
(2.41c)theareagot very hot.
(2.41d)TheFolsummencouldn’t adapt,and
(2.41e)they diedout.
(2.42)That’s what’s supposedto have happened.It’s thetextbookdogma.But it’s wrong.
Thediscoursedeictic referencein (2.42) is ambiguous;it canrefer to any of thenodeson the
right frontier of thediscourse:(thenodesassociatedwith) clause(2.41e),clauses(2.41d)-(2.41e),
clauses(2.41c)-(2.41e),clauses(2.41a)-(2.41e).
Discoursedeicticambiguityextendsto within theclauseaswell [Sch85], [Sto94]. For example,
in (2.43),thereferentof that couldbeany of thebracketedelements:
(2.43a) [ It talksabout[ how to [ go about[ interviewing ]]]
(2.43b)andthat’s goingto beimportant.
As notedby [DH95], the standardview on anaphoricprocessingis that we “pick up” the in-
terpretationof theantecedent,andthat in thenormalcase,thereis a coreferencerelationbetween
the antecedentandthe anaphor. The coreferencerelationis oneof identity, andthe antecedentis
“there”, waiting to be“pickedup”. Thus,in (2.44),mygrandfatheris saidto becoreferentto he:
(2.44)My grandfatherwasnota religiousperson.Heevenclaimedtherewasno god.
However, thefact that theinterpretationsof discoursedeixisarenot grammaticalizedasnouns
prior to discoursedeictic reference,andthefact that therearestructuralrestrictionson their refer-
ence,leadssomeresearchersto arguethat they arenot presentasentitiesin the discoursemodel
prior to discoursedeictic reference.Accordingto theseresearchers,their entity readingis coerced
andaddedto thediscoursemodelvia discoursedeicticreference.
28
![Page 46: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/46.jpg)
Typecoercionis atermtakenfrom computerscience,whereit definesanoperationby whichan
expressionwhichis normallyof onelogical typeis re-interpretedasanother(e.g.whenanintegeris
understoodasa Booleanvalue).Typecoercionis usedto explain a rangeof linguistic phenomena,
suchaswhenanexpressionwhich is indeterminateasto logical typeis ’coerced’into oneparticular
interpretationandthusacquiresa fixedtype.Modelsof how coercionis achievedvary.
[Web91] arguesthat deictic useis an ostensive act, that distinguisheswhat is pointedto and
whatis referredto, whichmaybethesame,but neednotbe.Thisostensiveact,functionsto reify, or
bringinto thesetof entities,somepartof theinterpretationsof clauseswhichwerenotpresentin the
setof entitiesprior to theostensive act.Sheusesreferringfunctions8 to modelhow thereificationis
achieved,becausethey allow thedomainof what is pointedto (demonstratum)to bedistinguished
from therangeof whatis referredto (referent):
f : D K R , whereD is comprisedof focusedregionsof thediscourse,andR is asetof possible
interpretations.
In (2.41), the domainof the referring functionsare the elementsat the right frontier of the
discourse,and function applicationyields a rangeof event tokens(things that can happen). By
virtue of thereferringactionof thefunction,thesenew ‘entities’ (eventtokens)areaddedto E.
[Sto94] takesWebber’s modelonestepfurther, arguing that a discoursedeictic pronounwill
take its referentfrom therightmostsibling of theclausein which it is contained, onceits clauseis
attachedor adjoinedto the tree. That referentcannotbe found in a nodethatdominatesthenode
containingthediscoursedeicticis easyto see,becausethatwould make thedeicticself-referential,
asin (2.45),wheretheindice + indicatesthediscoursesegmentwhoseinterpretationis thereferent
of thediscoursedeictic. As theexamplemakesclear, a discoursedeicticcannotalmostnever refer
to a segmentin which it is contained.Theonly exceptionis textual deixis,asin (2.46),wherethe
demonstrative canreferto the text in which it is contained.
(2.45)*[ wxVy+#( � is aneatidea.]�(2.46)[ wxVy+#( � is a truesentence.]�
8Referringfunctionshave beenusedby [Nun79] to modelhow nounsin generalachieve their reference.
29
![Page 47: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/47.jpg)
To arguethat thereferentwill not befoundin a nodethat is dominatedby thenodecontaining
thediscoursedeictic,[Sto94] first evokestheuseof discourserelations,arguing that if a discourse
deicticrefersto a segment,it will alsobein a discourserelationwith thatsegment.He thenargues
thatwhile discoursedeicticreferenceto embeddedclausesmight beviewedasanexceptionto this
generality, this exceptioncanbe avoidedby replacingWebber’s useof referringfunctionswith a
possibleworld semanticsin which thesemanticinterpretationof theelementsat the right frontier
of the discoursemake a variety of ’entity’ interpretations,or “information states”(see[Kra89]),
availableto thediscoursedeictic. For example,he arguesthatmodality in (2.47)makesavailable
assertionsaboutat leasttwo informationstates:(1) Mary left, and(2) Johnthoughtthe context
assertedof (1). The discoursedeictic in (2.48a)referencesthe first informationstate,andthat in
(2.48b)referencesthesecondinformationstate.
(2.47)JohnthoughtMary left.
(2.48a)He thoughtthishappenedyesterday.
(2.48b)Thiswaswrong.
[DH95] take a view similar to [Web91], exceptthey arguethat typecoercionis just oneof the
possiblereferent-creatingoperationsevokedby theuseof adiscoursedeictic.They arguethateach
timeananaphoris used,thedegreeto whichits antecedentis “there” will vary, andtheeffort needed
to “pick it up” will vary. In theirview traditional“coreference”asthemosttrivial case:theresultof
applyingtheidentity relationto theantecedent’s extension.They proposethatat leastthefollowing
operationsareneededto explainhow thereferentof a discoursedeicticis created:H Summationandcomplex creation:
Theseoperationsassemblesets.A setcanbeassembledby logicalconjunction,asin (2.49),or
by otherdiscourserelations,asin (2.50)(bracketsindicatethediscoursewheretheoperation
createstheantecedent):
(2.49)[Interestratesrose.Therecessionmayreduceinflation. Capitaltaxationis lower.] This
meansbrightertimesfor thosewhohave money to save.
(2.50)[If a white persondrivesthis carit’s a “classic”. If I, a Mexican-American,drivesit, it
30
![Page 48: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/48.jpg)
is a “low-rider”. ] Thathurtsmy pride.H Typecoercion:
This operationis asabove, when the semanticsof an elementin the clausecontainingthe
deicticcausesanexpressionto becoercedinto oneparticularinterpretation.For example,the
verbcancoerceaninterpretation,asin (2.51)where“happen”coercesaneventinterpretation,
or thepredicatenominalcancoerceaninterpretation,asin (2.52).
(2.51)Mary wasfired. Thathappenedlastweek.
(2.52)I turnedleft. Thiswasawisedecision.H AbstractionandSubstitution:
The abstractionoperationabstractaway from specificevents,as in (2.53), wherethe an-
tecedentis “beatingone’s wife” not “Smith’s beatinghis wife”, while thesubstitutionopera-
tion substitutesoneelementof theantecedentfor another, asin (2.54),wheretheantecedent
is “X beatshis wife”:
(2.53)Smithbeatshis wife althoughthiswasforbidden50yearsago.
(2.54)Smithbeatshis wife andJohndoesit too.
Regardlessof whetherwe assumethatclausesalreadymake availablea setof semanticvalues,
or whetherwe usea referringfunctionor oneof any numberof operationsto representhow these
valuesaremadeavailable,discoursedeixisusedoesn’t determinewhich entity interpretation(s)is
(are)chosenasthe referent. Within the domainof the right frontier, the semanticsof the clause
containingthediscoursedeicticwill determinewhichof theavailableobjectsareselected.
In particular, as[Ash93] notes,thesub-categorizationframeof theverbshouldrestrictthepos-
sible referents.Sowhile theembeddedclausein (2.55)canbe interpretedasa variety of abstract
objects,thinkssub-categorizesfor a propositioninterpretationof “Mary is a genius”,asdoesthe
complex form becertainof. Similarly, happensub-categorizesfor aneventinterpretation,surprise
sub-categorizesfor a factinterpretation.
(2.55)Johnthinksthat[Mary is agenius].Johnis certainof it.
31
![Page 49: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/49.jpg)
2.3.6 Summary
In this section,we overviewed the three-tieredmodelof discourseof GroszandSidner, in which
threeinteractingcomponentsaccountfor the structuringof the text into segments,eachof which
servesa purposeandcreatesa salientspacecontainingthe informationrelevant to that segment.
Their focuson intentionsasthe“relations” linking discoursesegmentsreflectsamoregeneralprag-
maticapproachto discourse.In sometreatmentsdiscourseis viewedasa plan,structuredinto sub-
goalswhosefulfillment achievesanoverall goal(see[LA90] for references).Othertreatmentscon-
cerntherole of discoursesegmentsin argumentunderstanding[Coh84]. RelevanceTheory[SW86]
is anotherpragmaticapproachproposedasa modelof a hearer’s interpretationprocess,in which
therelevanceof every segmentto thecontext is determinedbasedon a numberof interactingcon-
straints.Currentwork in dialogue(c.f. [SIG02]) investigatesintentionsin termsof “dialogueacts”.
BecauseGroszandSidnerview thepossibleintentionsthatcanunderliea discourseasinfinite,
structuralrelationsbetweensegmentsplay an importantrole in discoursecoherence.By distin-
guishinga focusspacefor eachsegmentthey modelsub-clausalcoherenceacrosssegments,and
enableCenteringTheoryto modelsub-clausalcoherencewithin segments9. Webber’s tree-based
modelsimplifiesthe GroszandSidnermodelby combiningthe componentsof text structureand
attentionalstateinto asinglestructure,while keepingthemconceptuallydistinctvia thenotionof a
right frontier, which is shown capableof modelingconstraintson discoursedeicticreferenceto the
interpretationof discoursesegments.
Groszand Sidner’s model (and Webber’s revision) provides a detailedaccountof the high-
level structuringof text in termsof attentionandintention; relationsbetweenpropositionsplay a
subsidiaryrole, servingalong with cuephrasesand utterancelevel intentionsto help the reader
recognizethe writer’s intentionsfor eachsegment. The detailsof how propositionalrelationsare
computedrecursively to build discoursesegmentsandhow theresultsarerepresentedarenot pro-
vided. In thenext section,wewill discussa tree-basedmodelthatadoptsasimilarly simpleview of
propositionalrelations,but definestheir role in theconstructionof thetreeprecisely, andclaimsto
modelsub-clausalanaphoraresolution.
9Someresearchershave alsousedCenteringasa modelof anaphoraresolution(see[BWFP87])
32
![Page 50: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/50.jpg)
2.4 A TreeStructure with a Syntax-SemanticInterface
[Pol96] presentsa context free grammar(LDM) for incrementaldiscourseparsing[SP88]similar
to [Web91], but combinedwith grammarrulesincorporatingpropositionalrelationsanda dynamic
logic framework (DQL) for describingthe structuredsemanticcomponentthat resultsfrom the
parsingprocess[PSvdB94]. The resultingmodelprovidesanaccountof how anaphoraresolution
[vdB96, PvdB99, Lag98] andtemporalinterpretation[PvdB96] work acrossstretchesof discourse.
2.4.1 Constituentsand TreeConstruction
In LDM, thesurfacestructureof discourseis composedof discourseconstituentunits(DCUs)and
discourse operators (DOs). DCUs aresemanticallymotivatedstructuresthat carry propositional
information;an elementaryDCU, typically a clauseor sentence,is any minimal utteranceencod-
ing a singleeventor stateof affairs indexed for context, includingphysicalandsocialsituationof
utterance(real or modeled),genreunit, modality, polarity, andpoint of view. DOs expressnon-
propositionalinformation,suchassemanticandstructuralrelationshipsamongDCUs, andprag-
maticinformationabouttheattitudeof thespeaker andthesituationof utterance.Examplesof DOs
includelogical operators,vocatives,(dis)affirmations,certainparticles,exclamations,connectives,
andtemporalmodifiers.
Complex DCUs aredefinedrecursively, via theattachmentof elementaryDCUs to DCUs the
growing parsetreeto createoneof threetypesof structures:H coordinations, includinglistssuchastopicchainsandnarrativesH subordinations, includingelaborationsandinterruptionsH binary-attachments, includingadjacency pairs,logical relationsandrhetoricalstructures
LDM canbe viewed asa limited lookaheadparserwhich acceptselementaryDCUs asinput
andbuildssimultaneouslyastructuralandsemanticdiscourserepresentation[SP88].A discourseis
representedasanopenright discourseparsetree,composedof C (coordination)S (subordination)
33
![Page 51: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/51.jpg)
andB (binary-attachment)non-terminalnodesandelementaryDCUsasterminalnodes.Eachele-
mentaryinput DCU is attachedasthe right child of anavailable, existing or newly created,node.
As in [Web91], only DCUson theright edgeof thegrowing parsetreeareavailablefor theattach-
mentof anincomingDCU; theoperationsfor attachinganincomingDCU correspondto [Web91]’s
attachmentandadjunctionoperations[Gar97b]; right attachmentis exemplifiedin Figure2.5.
Figure2.5: LDM Right-AttachmentOperation
2.4.2 The SyntaxSemanticInterface
Simultaneouswith theincrementalconstructionof discoursestructure,thesemanticrepresentation
of thediscourseis updatedwith theinterpretationof theincomingDCU. LDM is in essencea typed
unificationbasedsentencegrammaraugmentedwith a setof discoursegrammarrules. EachDCU
containssemanticinformationin theform of typedfeaturestructures,wheretypesareorderedalong
a typehierarchywhich allows for informationinheritanceandtypeunification10. For example,the
featurestructurefor thebasicDCU Johnsmiledis shown in (2.56),wherebasicrepresentsthetype
of elementaryDCUs and (/z�{q| representsthe semanticsof John smiled. The SCHEMA featureis
identicalto theSEM featurein basicDCUs.
(2.56) }~~�#� j�(�+#iSEM (qz�{/|SCHEMA (qz�{/|
�&���10Additional informationis alsocontainedin eachDCU, asmentionedabove; see[Pol96] for details.
34
![Page 52: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/52.jpg)
Discoursegrammarrulesthenspecifyhow to combineDCUs into biggerDCUs,andhow the
featurestructuresof thechild constituentscombineto yield thesemanticsof theparentconstituent.
DOs signal the applicationof thesegrammarrules. For example,constructionof a coordination
structurecanbeillustratedby thegrammarrule for a list, statedasin (2.57).In [PSvdB94], coordi-
natingconjunctions� and,or,...� signalthata list is to beconstructedor extended.
(2.57)}~~� )r+�(�bSEM )r+�(�b�z4� .�_�M��%� .�_ g |SCHEMA ^q.�W�z4� .�_ M �%� .�_�gC|
�&��� K}~~� -`b#op.*.SEM � .�_�MSCHEMA ��i�VA.�_�j M
�&��� ,
}~~� -pb�op.C.SEM � .�_ gSCHEMA ��i�V;.�_�j/g
�&���Syntactically, this rule statesthat any two discoursetreescancombineto form a new treeof
type list. Semantically, this rule producesa list relationbetweenthe two trees(indicatedby the
featureSEM), andconstrainsthis relation to be betweentwo treeswhosegeneralizationis non-
trivial, wherethegeneralizationof two terms � .�_ M and � .�_�g yieldsthemostspecifictermwhich
subsumesboth ��.�_ M and ��.�_�g . TheSCHEMAfeatureindicatesthis term.For example,giventhe
list JohnsmiledandPhil cried, thevalueof theSCHEMA featurewill bethegeneralizationof the
twoclauses,roughlymanexpressedemotion, wheremanandexpressedemotionaresetof objects
sharinga commonproperty11. Notethatthis rule extendsa list relationwhenthegeneralizationof� .�_�g is ��i�V;.�_�j M .In [Lag98]’s versionof LDM, therule for constructingopV;.�b�T�o7+'i�jq) coordinations(e.g.abinary-
attachment)is very similar to the rule for lists, exceptthata (non-trivial) generalizationis not re-
quired.Rhetoricalcoordinationsaresignaledby DOssuchastherefore, so,thus,accordingly.
Theconstructionof subordinations, whichmaybesignaledby DOssuchasbecause, sincediffer
from coordinationsin thatno generalizationis calculated.TheSCHEMA andSEM featuresof the
parentDCU in subordinationstructuresaregiventhevaluesof themainclause.
11see[PSvdB94,vdB96] for theformal computationof SEMandSCHEMAin DQL.
35
![Page 53: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/53.jpg)
2.4.3 Retrieving Antecedentsof Anaphora fr om the Tree
LDM claimsto modelconstraintson theantecedentsof anaphoraof incomingDCUs,asillustrated
in example(2.58),takenfrom [PvdB99].
(2.58a)Susancamehomelateyesterday.
(2.58b)Doris hadheldherupat work.
(2.58c)Shedidn’t evenhave time for dinner.
In (2.58),therelationshipbetweenDCU (a) andDCU (b) is a subordinationbecauseDCU (b)
suppliesmoredetailedinformationaboutwhy Susancamehomelate.DCU (c) continuesdescribing
thestateof affairsof Susan’s evening,andis thereforein a coordination relationwith (a). Dueto
the specificationof the semanticsat eachnodethat is provided in the LDM grammarrules for
subordinationandcoordination,only Susanis availableasa potentialreferentfor theanaphor, she,
in (c). The treefor this discourseis shown in Figure2.6, wherethe featurestructureshave been
simplifiedto show only thetypeof DCU andtheavailableantecedents.� i8T7T�o>-p+4WUj/b�+'T�WSusan �� � � � � �������� (Ck � T�o>-p+4WUj/b�+'T�WSusan �� � � ������ � jq(C+'i (a)
Susan � � � jq(C+'i (b)
Susan, Doris�� � jq(C+'i (c)
Susan �Figure2.6: LDM TreeStructurefor Example(2.58)
2.4.4 The NeedFor Upward Percolation
[Gar97b] observesthatwhile theLDM discoursegrammarrulesspecifyhow thesemanticsof child
DCUs combineto yield the semanticsof the parentDCUs, the semanticsof the restof the tree
remainsunchanged.Shearguesthattherearetwo mainproblemswith this lack of “upwardperco-
lation”. First,thesemanticsof thediscoursecannotbereadoff eithertherootor theright frontierof
36
![Page 54: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/54.jpg)
thetree.That it cannotbereadoff theroot is relatively obvious; that it cannotbereadoff theright
frontier is illustratedusing(2.59). TheLDM treeassociatedwith this exampleis shown in Figure
2.7;whereonly thesemanticsof eachDCU is shown at eachnodefor simplicity.
(2.59a)Weweregoingto seeoursontonight
(2.59b)but we arenot
(2.59c)becausetheyoungeroneis cominghomefor dinner
(2.59d)becauseheis working in theneighbourhood
(2.59e)soheis cominghomefor dinner
(2.59f)sowe arenot
a but b� � � � ������j ((b becausec) sof )� � � � ������(b becausec)� � � ������ ((c becaused) soe)� � ����
(c becaused)� ���i - .f
Figure2.7: LDM TreeStructurefor Example(2.59)
If thesemanticsof thediscoursearereadoff theright frontier andconjoined,we getonly: ((a
but b) and((b becausec) sof) andf).
Thesecondmajorproblem[Gar97b] noteswith LDM’ slackof upwardpercolationisaninability
to retrieve the antecedentsof discoursedeictic reference.As [Web91] argues,the right frontier
shouldrepresenttheavailableantecedentsof discoursedeixis; obviously if the right frontier does
not containtherequiredinformation,it will notbeavailableto thediscoursedeictic.
Gardentproposesanalternative methodof treeconstructionanda specificationof thesyntax-
semanticinterfacein which upwardpercolationis incorporated,alongwith thediscoursegrammar
rules of LDM. We will discussher approachin detail in Chapter4. [Sch97]’s extensionof her
approachincorporatesasemantic-pragmaticinterface.
37
![Page 55: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/55.jpg)
2.4.5 Summary
In summary, LDM providesa preciserepresentationof discoursestructure,a formal representation
of discoursesemantics,andaspecificcalculationof theinformationavailableat intermediarynodes.
Theauthorsarguethat for this reasontheLDM modelhasanadvantageover [GS86], which relies
ontheinferenceof attentionalandintentionalstates.However, theLDM modelmakesnoreference
to intentionsat all, andthe inferenceprocessis not described,althoughthey do notethat appeals
to inferenceandworld knowledgearerestrictedto specificmomentsin the interpretation,i.e. the
momentof DCU attachmentto thediscoursetree. Moreover, while LDM, like [GS86], claimsto
provideanaccountof anaphoraresolution,Gardentshowsthatthelackof upwardpercolationmakes
it unableto accountfor theresolutionof discoursedeixisanaphora.
In thenext section,we will discussa different tree-basedmodelwhich, thoughit returnsto a
descriptive approachof discoursecoherence,is widely used,becausein addition to providing an
extensive descriptionof propositionalrelations,it alsodefinesthediscoursestructuresthat canbe
producedwith them. We will then look at an alternative theory which replacessyntacticstruc-
ture with a structuredsemantics,andmodelsworld knowledgeandthe inferenceof propositional
relations.LDM arguesthis modelis lesstractable,becauseit doesnot separatethesyntaxandse-
manticsof discourse,andreferenceto world knowledgeandinferenceis lessrestricted.Thetheory
goesfurtherthanLDM however, by presentinganaccountof aseparatecomponentof intentions.
2.5 A DescriptiveTheory of DiscourseStructure
2.5.1 Analyzing Text Structure
RhetoricalStructureTheory(RST)[MT88] is oneof thesimplestmodelsof discourse,in thatit is a
purelydescriptivetheoryof text organization.RSTdescribestext structurefrom thepoint of view
of a text analyst,who hasaccessto thetext, knowledgeof context andthecultural conventionsof
thewriter, but doesnot have accessto thewriter. Therefore,theanalyst’s job is to judgethemost
plausiblerelationsthat thewriter intendedto convey. This judgmentdoesnot rely on morpholog-
ical or syntacticsignals;theauthorsclaim to have foundno reliableunambiguoussignalsfor any
38
![Page 56: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/56.jpg)
relations.Recognizingintendedrelationsis to reston functionalandsemanticjudgmentsalone.
The analystchoosesfrom the list of RST relationsin Table2.10. In this table, relationsare
groupedaccordingto their similarity in definition; theauthorsacknowledgethatalternative group-
ingsarepossible,oneof whichis thedistinctionbetween“subjectmatter”relations,whoseintended
effect is that the readerrecognizesthe relation,and“presentational”relations,whoseintendedef-
fect is to increasesomeinclination in thereader, suchasthedesireto actor believe someassertion.
“presentational”relationsareitalicized.
Table2.10:Organizationsof RSTRelationDefinitions
EvidenceandJustify AntithesisandConcession RestatementandSummaryEvidence Antithesis RestatementJustify Concession Summary
Relationsof Cause ConditionandOtherwise BackgroundVolitional Cause Condition EnablementandMotivationNon-Volitional Cause Otherwise EnablementVolitional Result InterpretationandEvaluation MotivationNon-Volitional Result Interpretation OtherRelationsPurpose Evaluation Sequence
Circumstance Elaboration ContrastSolutionhood
Nuclearityis assumedto bea centralorganizingprincipleof text; for themajority of relations,
thepiecesof text beingrelatedcanbedistinguishedinto a WckAi�)2.�k�( andsatellite, with thenucleus
representingthewriter’s maincommunication,andthesatellitesproviding subsidiaryinformation.
Thepredictionis thatif thenucleusis removed,thesignificanceof theinformationin thesatellite(s)
will not be apparentand thereforethe text will be incoherent,but if the satelliteis removed, the
resultingtext will still be coherentand resemblethe original in the form of a “synopsis”. RST
relationsarethusdefinedin termsof nuclearityandthewriter’s intent.As anexample,thedefinition
of the Evidencerelation is given in Table2.11, whereR representsthe reader, W representsthe
writer, N representsthenucleus,andSrepresentsthesatellite.
Thetext analystusesRSTrelationsto relatetext spans. Atomic text spansaregenerallyclauses,
exceptthatclausalsubjects,complementsandrestrictedrelative clausesarenot treatedin [MT88]
39
![Page 57: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/57.jpg)
asindependenttext spans.
Table2.11:Evidence:RSTRelationDefinition
relationname EVIDENCEconstraintson N R might notbelieve N to adegreesatisfactoryto Wconstraintson S R believesS or will find it credibleconstraintson N+S R’scomprehendingS increasesR’sbelief of Ntheeffect R’sbelief of N is increased
Complex text spansarestructurescalledschemaapplications. A schemaapplicationis a setof
adjacenttext spans(atomicor complex) linkedby anRSTrelationaccordingto oneof fivestructural
arrangements,calledschemas. Eachrelationhasacorrespondingschema,exemplifiedin Figure2.8;
therelationsnot shown all usetheschemalabeledwith the“circumstance”relation.Arcs represent
the relationholding betweentext spans,which are representedby horizontallines. The nucleus
is distinguishedfrom the satelliteby the direction of the arrow, and eachvertical line descends
from the text spanbeingdecomposedby a schemaapplicationdown to thenucleusof theschema
application.
Figure2.8: RSTSchemas
Schemasdonotconstraintheorderingof nucleusor satellite,they allow arelationthatis partof
a schemato beappliedany numberof times,andin multi-relationschemas,they requireonly one
of therelationsto hold. However, anumberof constraintsmustbesatisfiedto producea valid RST
structure.An RSTstructuremustbecomplete, consistingof asetof schemaapplicationscontaining
40
![Page 58: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/58.jpg)
aschemaapplicationthatconstitutestheentiretext. Every text span,exceptfor theentiretext itself,
mustbe connectedaseitheran atomicspanor a constituentof anotherschemaapplication.Each
schemaapplicationmustbeunique, consistingof adifferentsetof text spans,andin amulti-relation
schema,eachrelationmustapplyto adifferentsetof text spans.Finally, adjacencymustbesatisfied,
in thattheresultof eachschemaapplicationconstitutesonetext span.
An exampleof an RST structureconsistingof two evidencerelationsis shown in Figure2.9.
Eachtext spanis numbered;atomicnumberscorrespondto the text units in (2.60),andcomplex
numbersrepresentundecomposedunitsof thestructure.
(2.60)
(unitM ) This computertax programreally works.
(unitg ) In only a few minutesI finishedmy tax return.
(unit� ) I printedit for you to see.
Figure2.9: EvidenceRelation
[MT88] allow thatmultiplicity mayarisefrom text ambiguityandresultingdifferencesin ana-
lysts’ judgmentsabouttherelationsholdingbetweentext spans.It is assumedhoweverthatthemore
coherentthewriter hasmadethetext, theclearereachchoiceof relationis for thetext analyzer.
41
![Page 59: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/59.jpg)
2.5.2 The Needfor Multiple Levelsof DiscourseStructure
[MP92] provide an influential argumentagainst[MT88]’s claim that thoughsubject-matterand
presentationalrelationscanbe distinguished,in general,therewill be a singlepreferredrelation
holding betweenconsecutive text spans.They arguethat this distinctionis in fact a conflationof
the two levels of discourseinterpretationidentified by [GS86]: the informational level, and the
intentional level, respectively, andthata completemodelof discoursecannotdependon analyses
in which theselevels are in competition. They supportthis argumentfirst by showing both that
informationcanflow betweentheselevelsto producetherelationsbetweentext spansin adiscourse,
asillustratedwith (2.61)-(2.62):
(2.61)GeorgeBushsupportsbig business.
(2.62)He’s sureto vetoHouseBill 1711.
[MP92] arguethat thepresentationalrelationEVIDENCE is a plausibleRSTrelationbetween
thenucleus(2.62)andthesatellite(2.61)(Table2.11). Equallyplausible,however, is thesubject-
matterVOLITIONAL-CAUSErelation,where(2.62)is thenucleusand(2.61)thesatellite.[MT88]’s
definitionof aVolitional-Causerelationis givenin Table2.12.
Table2.12:Volitional-Cause:RSTRelationDefinition
relationname VOLITIONAL-CAUSEconstraintsonN N presentsa volitional actionor a
situationthatcouldhave arisenfrom avolitional action.
constraintsonS noneconstraintson theN+Scombination S presentsasituationthatcould
have causedtheagentof thevolitional actionin N to performthataction;without thepresentationof S,R might not regardtheactionasmotivatedor know theparticularmotivation;N is morecentralto W’spurposesin puttingforth theN-ScombinationthanS is.
theeffect R’s recognizesthesituationpresentedin Sasacausefor actionof N
42
![Page 60: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/60.jpg)
[MP92] argue that if the readerknows (andknows that the writer knows) that the bill places
stringentcontrolson manufacturing,thens/hecanconcludethat(2.61)is evidencefor (2.62),thus
reasoningfrom informationto intention. Alternatively, if the readerdoesn’t know anything about
thebill, but expectsthewriter to supporttheclaimthatBushwill vetoit, thens/hecanconcludethat
(2.61)is acauseof (2.62),thusreasoningfrom intentionto information.
[MP92] also show that spanscan be relatedsimultaneouslyon both levels, as in (2.63). At
the informationallevel, a plausibleRST analysisis that (2.63c) is the nucleus,the writer’s main
informationalcommunication,(2.63 a) is a CONDITION on (2.63 b), and (2.63 a) and(2.63 b)
togetherarea CONDITION on (2.63c). This RSTstructureis shown first in Figure2.10.Suppose
howeverthatthewriter is planningasurprisepartyfor thereader. Thenattheintentionallevel, (2.63
a) is thenucleus,theactionthatthewriter wishesthehearerto perform,(2.63c) MOTIVATES(2.63
b), andtogetherthey MOTIVATE (2.63a). ThisRSTstructureis shown secondin Figure2.10.
(2.63a) Comehomeby 5:00.
(2.63b) Thenwe cango to thehardwarestorebeforeit closes.
(2.63c) Thatwaywe canfinish thebookshelvestonight.
Figure2.10:RSTConditionandMotivationRelations
Becausetheintentionalandinformationalstructuresfor this discoursearenot isomorphic,they
cannotbeproducedsimultaneously.
43
![Page 61: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/61.jpg)
2.5.3 “Elaboration” asReference
[KOOM01] show that the object-attribute elaboration relationover- andunder- generatesRST
structures.[MT88] definetheelaboration relation(of which theobject-attribute typeis subset5)
asshown in Table2.13.
Table2.13:Elaboration:RSTRelationDefinition
relationname ELABORATIONconstraintson N noneconstraintson S noneconstraintson theN+Scombination Spresentsadditionaldetail
aboutthesituationor someelementof thesubjectmatterwhich is presentedin N orinferentiallyaccessiblein N inoneor moreof thewayslistedbelow. In thelist, if N presentsthefirst memberof any pair,thenS includesthesecond.1. set: member2. abstract: instance3. whole: part4. process: step5. object: attribute6. generalization: specific
theeffect R’s recognizesthesituationpresentedin Sasprovidingadditionaldetailfor N.R identifiestheelementofsubjectmatterfor whichdetail is provided.
In words,[MT88] definetheobject-attribute elaboration relationto hold betweenN andS if
N ‘presents’an object (e.g. containsa mentionof it), andS subsequentlypresentan attribute of
this object. [KOOM01] have found this relationto be widely usedin museumguidebooks.They
illustratethefactthatit under-generateswith (2.64a)-(2.64d):
(2.64a) In thewomen’s quartersthebusinessof runningthehouseholdtookplace.
(2.64b) Muchof thefurniturewasmadeupof chestsarrangedvertically in matchingpairs.(...)
44
![Page 62: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/62.jpg)
(2.64 c) Femaleguestswere entertainedin theserooms,which often hadbeautifully crafted
woodentoilet boxeswith fold-away mirrors andsewing boxes,andfolding screens,paintedwith
birdsandflowers.
(2.64d) Chestswereusedfor thestorageof clothes.. .
In (2.64b), theobjectchestsarementioned.Discussionof this objectis takenup againin (2.64
d). Thetext is clearlycoherent,but thedesiredRSTanalysiswhere(2.64d) is asatelliteof (2.64b)
usingobject-attribute elaboration is not possible,because(2.64b) and(2.64c) arebothalready
satellitesof (2.64a) underanelaboration relation.
[KOOM01] illustratethefactthattheobject-attribute elaboration relationunder-generatesby
comparing(2.65a)-(2.65b) with (2.66a)-(2.66c) :
(2.65a) Arts-and-Craftsjewelstendto beelaborate.
(2.65b) However, this jewel hasasimpleform.
Thediscoursein (2.65a)-(2.65b) displaysa concessionrelationbetweenthesatellite,(2.65b),
andthenucleus,(2.65a). However, whenanobject-attribute elaboration relationintervenes,asin
(2.66a)-(2.66c) thediscourseis incoherent,althoughRSTallows thestructure,with (2.66c) now
beingthesatellitefor thecomplex unit (2.66a)-(2.66b), with (2.66a)asthenucleus.
(2.66a) Arts-and-Craftsjewelstendto beelaborate.
(2.66b) They areoftenmass-produced.
(2.66c) However, this jewel hasasimpleform.
If compositionality, continuousconstituency, and a tree structurearemaintainedas RST as-
sumptions,thenRSTundergenerates.[Sib92] hasarguedfor relaxingthecontinuousconstituency
constraint(i.e. that S be adjacentto N, or adjacentto a satelliteof N). [KKR91] hasarguedfor
relaxingthe treestructureconstraint(i.e. that eachtext span,exceptfor the spanconstitutingthe
entiretext, beinvolvedin exactlyoneschemaapplication,with noover-lappingspans,andnospans
not linkedto otherspans).
[KOOM01] take anothertack, arguing that the over- andunder-generationproblemsarisebe-
causeobject-attribute elaboration is notadirectrelationbetweenpropositions,but rather, adirect
45
![Page 63: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/63.jpg)
(e.g. identity) relation betweenobjects,and a spuriousassociationbetweenpropositions. They
arguethat local andglobal focusmechanisms[WJP81, GS86]make theuseof this relationredun-
dant. They proposea revision of RSTin which theobject-attribute elaboration is removed,and
high-level text spansarerelatednot by RSTrelations,but by mechanismsof global focussuchas
informationallyredundantutterances(IRUs)[Wal93], nominalization,anddiscoursedeixis.
In [KOOM01]’s model,a coherenttext is a sequenceof focusspaces,calledentity-chains, that
succeedeachotherin a legalmanner, asexemplifiedin Figure2.11.
Figure2.11: [KOOM01]’sDiscourseModel
In thefigure,eachentity-chain,labeledEC1,etc,hasasits globalfocusanentityE,andconsists
of asequenceof RSTtrees,eitheratomictext spans,shown assmallboxes,or complex structuresof
RSTrelations(minustheobject-attribute elaboration relation),shown astriangles,in which the
root nucleusof eachtreeis aboutE. In a legal sequenceof entity-chainsthefocusedentity in each
chainhasbeenmentionedsomewherein the W previous propositions,wherethevalueof W is still
anopenquestion.They call this a resumptionrelation, indicatedby directedarcsin thefigure,and
its felicitoususeis claimedto bea functionof its lineardistancefrom any previousmentionof it,
ratherthanbeinga functionof its relationshipto theright frontier of a discoursestructuretree.
2.5.4 Summary
RST claims to be able to describethe majority of naturally occurringtext, and hasfound wide
applicationin the literature. For example,[Fox87] hasdemonstratedhow humanexplanationsof
thechoicebetweenpronounsandfull NPsin expositorytext canbederived from RSTstructures,
[SdS90] defineasetof heuristicsfor recognizingRSTrelations,[Mar97] hasbuilt anRSTannotation
46
![Page 64: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/64.jpg)
tool and manualin which usersare instructedto selectfrom a hierarchicalversionof the RST
relations(e.g. they chooseelaboration only if no other relationfits) and[Mar00] shows that an
automatedmethodof labelingRST-typerelationscanpartially replicatehumanannotation,if “cue
phrases”andpunctuationareusedassignalsof thepresenceof particularRSTrelations.RST-type
relationshave alsobeenusedin combinationwith otherintentionalrelationsasplanningoperators
in naturallanguagegenerationsystems(see[Hov93, MP93]).
However, anumberof importantlimitationsinherentin theRSTapproachhavealsobeenraised.
First, MooreandPollackshow that RSTconflatesintentionswith treestructure.This hasserious
consequences.For example,anRST-basedsystemsuchas[Mar99] enablesoneto automaticallyde-
riveandenumerateall possibleRSTinterpretationsof a text, but doesnotprovide amechanismfor
choosingbetweenthem. Similarly, [Hov93]’s RST-basedsystemallows for multi-relationdefini-
tionsthatassigntwo labelsto consecutive discourseelements.Neithersystem,however, accommo-
datesconcurrent,non-isomorphicinterpretations.This is a problemfor all tree-basedapproaches;
if both levels are treatedstructurallythenmultiple structureswill alwayshave to be considered.
Second,[KOOM01] showed that the object-attribute elaboration relationboth over- andunder-
generatesthe spaceof discoursestructuresin an RST theory. Ratherthanrevise the assumptions
inherentin atreestructure,they proposethattreestructuresshouldholdonly within “entity chains”,
whichcorrespondroughlyto discoursesegmentsassociatedwith focusspacesin GroszandSidner’s
theory. Thedifferenceis thatKnott et. al donotconstrainfocusspacesashighly asastackor a tree
structuredoes,ratherthey proposea linearconstrainton thenumberof intervening“entity chains”
betweenreferenceto entitieswithin prior entity chains.
More generally, RST is simply not a completemodelof discoursestructure,in that it relies
wholly on reader’s intuitions,saysnothingaboutsub-clausalcoherence,definesno formal mecha-
nismfor computingtherelationsbetweentext spans,andprovidesnoobjectivemethodof justifying
their choiceof relationsover any other. Becausethey make useof so many morerelationsthan
any of theotherrelationswe have seen,suchjustificationis important;we needto proposesome
mechanismby which theserelationsareproduced,especiallyif they intuitively seemcapableof
describingthemajority of texts.
47
![Page 65: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/65.jpg)
In thefinal sectionof this chapter, suchamechanismis proposed.In thenext section,however,
we presentanalternative theoryof discoursecoherence,onewhichmodelsevery majorcharacteri-
zationof discoursecoherencethatwehavesofarseenin thischapterwithoutreferenceto asyntactic
treestructure.
2.6 A SemanticTheory of DiscourseCoherence
SDRT [Ash93, LA93] is a dynamicsemanticsapproachto discoursecoherence.It hastwo main
modules:a formal languagefor representingdiscoursecontext [Ash93], anda theoryof discourse
inference(DICE) [LA93] which is usedto computediscourserelations.[LA99] furtherproposea
separatemodulefor limited reasoningaboutintentionsandcognitive states.SDRT is alsoshown
to provide anaccountof anaphoraresolution;in particular, thesemanticsit proposesincorporates
thesemanticobjectsreferredto by discoursedeixis. We now returnto our discussionof discourse
deixis,in termsof thesesemanticobjects;thisdiscussionwhichwill provide thebackgroundfor our
studiesin Chapter3.
2.6.1 Abstract Objects
Sincetheearliestwork in logic andlinguistics,propositionshavebeenviewedasthesemanticinter-
pretationof sentences(c.f. [Mon74, CQ52]);studiesof adverbialmodificationandtensein formal
linguisticshave alsomadereferenceto eventualityinterpretations(c.f. [Dav67, MS88]). Proposi-
tions,aswell asstates-of-affairs, properties,facts,causes,andeffects, have no spatio-temporallo-
cation.For someeventualitiestoo, it maybedifficult to pinpointprecisespatio-temporalor sensory
coordinates:thefall of theRomanempire, for example[Ven67]. Theseinterpretationsareabstract.
Early work in naturallanguagephilosophy(c.f. [Ven67, Aus61, Str59]) providesdiscussionof the
propertiesof theseinterpretations.
The precisenatureof theseabstractionshasneverthelessproven difficult to pin down, partly
becausethey canbedifficult to distinguish.For example,thesentenceJohnwentto thestorecanbe
interpretedasanevent,it canbeattributeda truth value,it canbeviewedasa surprisingfact,or it
canbeinterpretedasaresultof John’sneedingclothes.Wecanview theseinterpretationsasobjects,
48
![Page 66: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/66.jpg)
asevidencedby thefactthatwereferto themusingnounphrases,e.g.thefall of theRomanEmpire.
Thattheseobjectscanbedistinguishedis evidencedby thefactthatwecanexplicitly indicatewhich
interpretationis beingreferredto, e.g. thefact that theRomanempire fell, theeventof theRoman
empire falling, etc.
Vendlerarguesthat we implicitly distinguishtheseinterpretationby the way we nominalize
them. Nominalizationtransformsa sentenceinto a noun phrase. The “essentialingredient” of
a nominalizationis a verb derivative. Vendlerarguesthat nominalizationsfall into perfectand
imperfectclasses,asin Table2.14.
Table2.14: [Ven67]’s ImperfectandPerfectNominalizations
imperfectnominals (2.67)It is fortunatethat Johnhasarrived unexpectedly.(2.68)John’s havingarrivedunexpectedlysurprisedme.
perfectnominals (2.69)Thebeautifulsingingof theMarseillestookall afternoon.(2.70)Theunexpectedarrival wentunobserved.
As shown in (2.67),nounclausenominalizationsallow theverb to take tense,auxiliary verbs
andadverbs,but they cannotbe modifiedby articlesor adjectives (e.g. *the beautiful that John
arrived). As shown in (2.68),-ing formsof verbsin nominalizationscantakeeither tense,auxiliary
verbsandadverbs,or articlesandadjectives,asshown in (2.69),but not both at once(e.g. *the
beautifulsinging*unexpectedly). As shown in (2.70),nounsderivedfrom verbsin nominalizations
cannottake tense,auxiliaryverbsor adverbs(e.g.the*unexpectedly*havingarrival); they canonly
take articlesor adjectives.
Sincetenses,auxiliariesandadverbscharacterizeverbs,andaregenerallyincompatiblewith
articlesandadjectives in nominalizations,andarenot permittedat all in perfectnominalizations,
Venderconcludesthat in perfectnominalizations,the verb is deadasa verb, while in imperfect
nominalizations,theverbis still aliveasaverb.
Vendlerfurtherdistinguishesloosecontainers andnarrow containers (i.e. the restof thesen-
tence),as in Table 2.15. Narrow containersdescribespatio-temporalqualitiesof events. They
permitonly perfectnominalizations,in which, if thereis a verb, it is dead.Narrow containersalso
49
![Page 67: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/67.jpg)
take nounswhichcanbehave like perfectnominals,e.g.firesandblizzards, unlike tablesandcows,
canoccur, begin, end,canbesuddenor prolonged;they canbereadasevents.
Table2.15: [Ven67]’s LooseandNarrow Containers
loosesubjectcontainers is probable/certain/unlikely/surprising/a factlooseobjectcontainers hedenied/mentioned/rememberednarrow subjectcontainers is slow/gradual/anevent/aprocess/anaction,occurs/beginsnarrow objectcontainers I watched,I heard,I felt, I observednarrow PPcontainers until/before/after/since
Loosecontainersascribepropertiesto facts.They permitboth imperfectandperfectnominal-
izations. Whenthey take an imperfectnominalization,theverb is alive; whenthey take a perfect
nominalization,however, analiveverbis attributedto it, asin (2.71).Whenthey takesimplenouns,
they arereadassuppressedimperfectnominals,asin ((2.72). Moreover, if a sentenceis not nomi-
nalized,it will berelativizedby a relative clausein theform of a loosecontainer(2.73).
(2.71)John’s singingof theMarseillessurprisedme.(read:thathesangtheMarseillaise)
(2.72)Theabominablesnowmanis a fact. (read:theexistenceof thesnowman)
(2.73)Johndied,whichsurprisedme.vs. *Johndied,whichwasslow.
Vendlerusesthesedistinctionsto investigatethenatureof otherabstract objects, suchaseffects
and results. Examplessuchas(2.74) - (2.75) indicatethat effectsdescribeperfectnominals,e.g.
events,changes,or processes.An effect canreacha large area,canbe felt, measured,registered,
canbeviolentanddangerous.Theseexamplesalsoshow thateffectsattributeeventsto otherevents,
alsodenotedby a perfectnominal.Similarly, othermembersof theeffect family of terms,product,
work,creation,upshot,issue, outcomearepredicatedof events.
(2.74)Themoon’s positionhasaneffect on themovementof theoceans.
(2.75)*That themoonhasits positionhasaneffecton theocean’s having movement.
Results, on theotherhand,like causes,consequences,reasons,motives,andexplanations, can
bestated,told, believed,probableor improbable,andsometimesfortunateor unfortunate,expected
or unexpected,sad,disastrous,or horrible,i.e.,describefactinterpretations(2.76).
50
![Page 68: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/68.jpg)
(2.76)Thattheoceanshave movementis a resultof themoonhaving its position.
Theseinterpretationsaredifficult to distinguish;whatemergesmostclearlyfrom thisdiscussion
is thatmany differentabstractinterpretationscanbeconveyedastheinterpretationsof sentences.Of
course,nominalizationsarenot thewayto convey thesesentences,noraresinglesentencestheonly
carriersof theseinterpretations.Discoursedeixis, aswe have seen,providesanothermechanism
for conveying them. And discoursedeixis canrefer to not only to the interpretationsof sentences
but to awidevarietyof syntacticconstituents,includingverbalpredicates,asin (2.31,sequencesof
sentences,asin (2.33),anduntensedclauses,asin (2.43),all of whicharerepeatedbelow.
(2.31)John[smiled]. He doesthat often.
(2.33)[I wokeupandbrushedmy teeth.I wentdownstairsandatebreakfast,andthenI wentto
work.] That’s all I did today.
(2.43)[ It talksabout[ how to [ go about[ interviewing ]]] andthat’s goingto beimportant.
What’s more, discoursedeixis referenceindicatesthat the rangeof abstractobjectsis even
wider thanVendleraddressed.For example,discoursedeixiscanalsorefernot only to speechact
interpretationsof sentences,as [Web91] noted(Table2.9, shown below as2.77), but as [DH95]
have shown, to the discourserelation betweensentences,suchas the contrastrelation in (2.50),
repeatedbelow, andevento apresupposeddefeasiblerulearisingfrom adiscourserelationbetween
sentences(See[Kno96] andbelow for a discussionof theserules),suchasin (2.78),where“if it’s
rainingthesunisn’t shining” is presupposedanddenied.
(2.77)Speaker A: Johnspeaksloudly. Speaker B: Repeatthat.
(2.50)[If awhite persondrivesthis carit’s a “classic”. If I, aMexican-American,drive it, it’s a
“low-rider”.] Thathurtsmy pride.
(2.78)[The sunis shiningalthoughit’spouringrain.] That’s a ruleBermudaalwaysbreaks.
Essentially, thereare as many abstractobjectsas thereare abstractnouns,and they can be
referredto implicitly via discoursedeixis,or explicitly with a demonstrative inferableNP [Pri81],
e.g. that fact. Therefore,in this thesiswe will extendthe term“abstractobjects”12 to cover all of
12It appearsthis termwascoinedby [Ash93].
51
![Page 69: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/69.jpg)
thesepossibilities.
[Ash93] classifiestherangeof “saturated”abstractobjectsasshown in Figure2.12. Also con-
tainedwithin theseclassificationnodes,but subjectto a slightly morecomplex linguistic analysis,
are “unsaturatedabstractobjects”. This differenceis akin to [DH95]’s “abstractionoperation”:
somememberof theantecedentclausemustbeabstracted,replacedor otherwisealteredto achieve
the referenceto an unsaturatedabstractobject. In (2.79), for example,we mustalter the referent
to theform “Mary shouldgo out with anentity coindexed by thespeaker”, andin (2.80)we must
changethevoiceof theantecedentto “take thegarbageout”:
(2.79[JohnsaidthatMary shouldgo outwith him], andBill saidthat too.
(2.80)[The garbagehadto betakenout], so that’s whatBill did.
Figure2.12: [Ash93]’s Classificationof AbstractObjects
Asher’s classificationorganizesabstractobjectsalonga scaleof “concreteness”;eventualities
are the mostconcreteandproposition-like objectsare the leastconcreteabstractobjects. Remi-
niscentof Vendler, Asherarguesthateventualitiesbehave mostlike concreteNP entities;they are
locatedin spaceandtimeandcanalsobecausal(2.81);in contrast,fact-like objectsarenot located
in spaceandtime but canbe causal(2.82); finally, proposition-like objectsareneitherlocatedin
spaceor time,nor canthey becausal(2.83). In theseexamples,we usethedemonstrative inferable
NP form to make cleartheAO interpretationof thefirst clause.
(2.81)TheJetsscored.ThateventcausedthePatriots’ coachto throw down his headphone.
(2.82)TheJetsscored.ThatfactcausedthePatriots’ coachto throw down his headphone.
52
![Page 70: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/70.jpg)
(2.83)TheJetsscored.*That propositioncausedthePatriots’ coachto throw down his head-
phone.
The differencebetweenreferenceto propositionsand facts is slight but interpretable:refer-
enceto propositionspredicateson a truth value,which appearsto betheonly propertythatcanbe
attributedto aproposition.In contrast,referenceto a facttakesits truth valuefor granted[Eck98].
2.6.2 A Formal Languagefor Discourse
In Section2.3.5we reviewed [Web91]’s useof referring functions,[Sto94]’s useof information
states,and[DH95]’ssetof operations,all of whichweremodelsof how abstractobjectsarecreated.
[Ash93]’s model usesa formal languageof discoursethat is an extensionof DRT [KR93].
DRT is a dynamicsemantics,analyzingmeaningin two steps.First, the DRS constructionalgo-
rithm providesa setof rulesfor theincremental(sentence-by-sentence) constructionof a semantic
representationof a discourse,calleda discourserepresentationstructure(DRS).Second,theDRT
correctnessdefinitionprovidesinstructionsfor homomorphicallyembeddinga DRSin a modelto
producethetruthconditionsfor adiscourse.Notethatwhile bottom-upDRSconstructionis largely
compositional,thereis noMontaguenotionof compositionalsemanticsatthediscourselevel,where
rulesfor semanticinterpretationcorrespondto syntacticrulesof construction.
Essentially, DRSconstructiontranslatesterminalnodesof thesyntactictreefor eachsentence
in a discourseinto a DRS,whoseunionthenforms theDRSof thediscourse,accordingto the in-
structionsfor correctness.A DRShastwo parts:auniverse,containingtherelevantdiscourseentity
references,anda conditionset,containingn-placeDRSpredicateswith discourseentity references
asarguments.In DRS(a)shown in Figure(2.13),x andy arediscourseentity references;thecondi-
tion setsaysthatx is aboy, y is Fred,andskicksy. To gettheDRS(b) for all of thediscourse,DRS
(a) servesascontext; thediscoursereferentsintroducedby thesecondsentenceareenteredinto the
conditionsetanduniversecreatedin (a). As shown DRS(b) containsoneincompletecondition(z =
?);anaphoraresolutionis required,to replace? by adiscoursereferentotherthanz. Accessibilityof
adiscoursereferentx to adiscoursereferenty is aconstraintwhichsaysroughlythatx is accessible
to y if it is in the universeof a DRS to the left, super-ordinateto, or the sameasthe universein
53
![Page 71: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/71.jpg)
which y is declared.After identifying ? with y, thecorrectnessdefinitionsaysthat (b) is a proper
embeddingin a modelM iff M containsFredandMax suchthatMax kicked FredandFredcried.
As shown in (c), sententialoperatorssuchas if...thencreatesubDRSs,as do many determiners,
negation,attitudes,belief operators,nominalizations,gerunds,complementclauses,etc.
Figure2.13:SampleDRSs
Like [Sto94], Asherdoesnotusecoercionto createabstractobjectinterpretations;like [Sto94],
heassumestheseinterpretationsarealreadypresent,in this case,asadditionalvariablesin DRSs.
To achieve referenceto eventualities,Ashersimply addsto aneventvariable . (or a statevariable( ) to theDRStranslationof verbs,whichcanbeidentifiedby anaphoraresolutionwith thevariable
introducedby thediscoursedeicticanaphor. Eventsummationis thendefinedto permit reference
to complex eventuality interpretations(e.g. 2.33). To achieve referenceto propositionand fact
interpretations,Ashersimply allows the variableintroducedby a discoursedeictic anaphorto be
identifieddirectly with an accessibleDRS (roughly, if the variablesin the universeof a DRS are
accessibleto adiscoursereferentx, sois theDRSitself).
As defined,however, DRT constructionprovidesno accountof discourserelationsor discourse
segmentation(or theability of a discoursedeictic to referto a discoursesegment).To build a DRS
for adiscourseasawhole,onesimplyaddstheDRSconstructedfor eachincomingsentenceto the
DRS onealreadyhad. Asherpostulatesan additional level of discourseinterpretationto provide
a semantictheory of discoursestructure;the the resultingstructureis called a segmentedDRS
54
![Page 72: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/72.jpg)
(SDRS).Essentially, anSDRSis a recursive structureof labeled(S)DRSs,with discourserelations
betweenthe labels,anda partial orderingon both the (S)DRSsandthe discourserelations. The
relationshave a truth-conditionalcontentconcerningthe relationof constituent(S)DRSsto each
other, but not all relationshave a truth-conditionalimpacton the contentof what is said,andthe
discoursedominancehierarchyrepresentedin SDRSalsohasno truth-conditionalimpacton the
contentof whatis said.
Note that while DRSsareamongthe basicconstituentsof an SDRS,andDRSsaretypically
viewedascorrespondingto sentences,Asherleavesopenthequestionof whetherconstituentDRSs
cancorrespondto a clauseor severalsentences,etc,notingthatpurposeplaysanimportantrole in
determiningindividualsegments[GS86]. EachSDRSalsocontainsadistinguishedDRS,adiscourse
topic, which summarizesthecontentof a constituentin anSDRSandbearsa particularstructural
relationto thatconstituent.
In an SDRS,every new constituent(S)DRSmustbe attachedto an antecedentlyconstructed
constituent.Only openor d-freeconstituents,however, areavailablecandidatesfor attachment.The
theorydistinguishestopic-updatingandSDRSupdatingwith an incomingDRS,via distinguished
discourserelations. Continuationand Elaborationrelationsare distinguishedas topic-based;to
attachto a constituentthey requireonly that it beopen. Thecurrent constituentis theconstituent
DRS containingthe information from the previous sentence,and is always open. Also openis
the SDRSin which the currentconstituentoccurs,andto any SDRSthat enclosesthat, etc. This
correspondsroughlyto theright frontier of thediscoursesyntactictree,but it is moregeneral,akin
to [KOOM01]’s notion of “resumptive links”, becausesubordinateconstituentsarenot treatedas
partof theattachment.
Non-topicbasedrelationsrequiretheconstituent� to which theincomingconstituentattached
to be both openandd-free, whered-freemeansroughly that � is not containedwithin an SDRS
whosetopic subsumes� .
An exampleof a simpleSDRSK is shown in Figure2.14,consistingof a (sub)SDRSK1 and
a DRS k L specifyingthe discoursetopic (indicatedby the arrow) which summarizestheseDRSs
andis in anElaborationrelationwith K1. K1 consistof DRSsk1-3 andthehierarchicaldiscourse
55
![Page 73: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/73.jpg)
relationsthatholdbetweenthem.
Figure2.14:SampleSDRS
Morecomplex SDRSsresultfrom relationsbetweennon-adjacentconstituents.For example,in
(2.84),k4 is relatedby thetopicbasedContinuationrelationto k1.
(2.84)
(k1) I atea lovely dinner.
(k2) I hadsalmon.
(k3) I hadtiramisu.
(k4) ThenI wentfor awalk.
In this case,the SDRSK containsa discoursetopic k0, a subSDRSK1, andan Elaboration
relationbetweenthem. K1 containsa subSDRSK2, its a discoursetopic k1, andan Elaboration
relationbetweenthem.k1 is alsoin a Continuationrelationwith k4. K2 containsk2 andk3 anda
Continuationrelationbetweenthem. As this exampleshows, multiple discourserelationsbetween
theconstituentsof anSDRSarepossible,so long asthey areaccessible.Theprocessof inferring
discourserelationsis describedbelow.
56
![Page 74: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/74.jpg)
2.6.3 Retrieving Antecedentsof Anaphora fr om the DiscourseStructure
In general,theeffect of updatinganSDRSis thatwhethera discoursereferent� maybeanaphor-
ically linked to anotherdiscoursereferentor discoursestructure� dependson whether � occurs
in a constituentthat bearsa discourserelation to � or the constituentin which � occurs. Other
constituentswill not yield potentialantecedents.
For example,in Figure2.14, this availability constraintpredictsthat � canbe resolved to j ,becausek2 is in a Continuationrelationwith k1, and i canbe resolved to � , becausek3 is in a
Continuationrelationwith k2, and k canresolve to j , becausek0 is in anElaborationrelationwith
K1. But if the text correspondingto k1 were“Kathleenis taller thanthepeoplesheworkswith”,
and the text correspondingto k3 were “She teacheswith them”, this constraintwould correctly
predictthat themcouldnot beresolvedto thepeoplesheworkswith. However, basedon examples
like (2.85),Asherrelaxesthisconstraintfor ParallelandContrastrelations.
(2.85)Johndoesnotbelieve that[Mary is treatinghim fairly]. But Fredis certainof it.
In suchcases,anaphoricreferenceis successfullymadeto anembeddedDRS,(thecomplement
of believe); thusAsherallows discoursereferentsor structuresembeddedin a constituent� that is
relatedby theserelationsto anotherconstituent� to betheantecedentsof discoursereferentsin � .
2.6.4 A Systemfor Inferring DiscourseRelations
In [HSAM93]’s approachto inferring discourserelations,discussedin Section2.2, discoursere-
lations are “proven” throughlogical abduction,wherethe total cost of a proof of eachpossible
discourserelationis determinedby thesumof thecostof abducingits premises,andthatthecheap-
estproof wins. [Lag98] notesthreeproblemswith this method. First, only onerelationwill be
chosen.Second,thecostsof differentdiscourserelationswill becomparedregardlessof possible
inconsistencies.Third, it is notclearhow thesecostsshouldbedetermined.While [HSAM93] sug-
geststhatpsycholinguisticexperimentscandeterminerelative costs,in reality theexperimentation
thatwouldberequiredto establishthesevaluesseemsno smallfeat.
DICE [LA93] is an alternative discourseinferencesystem,usedfor computingthe discourse
57
![Page 75: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/75.jpg)
relationsin SDRSs.Like [Keh95], discourserelationsaredefinedin termsof constraints,or rules,
thatmustbesatisfied,andlike [HSAM93] asystemof ruleapplicationis definedUnlike [HSAM93]
however, DICE is drivenby theprocessof determininginconsistencies.Multiple discourserelations
mayhold,solongasthey areconsistentwith eachother. Moreover, establishingdiscourserelations
is representedasa consequenceof linguistic, world, andlexical knowledge,whoseinteractionis
explicitly defined,ratherthanvia theassociationof coststo premises13.
Thedefinitionsof thediscourserelationsoriginallydiscussedin [LA93] areshown in Table2.16;
their definitionsaregiven in [Lag98]’s simplified format (Narrationis roughly the Continuation
relationdefinedin theprevioussection).
Table2.16:DICE: discourserelationdefinitions
Narration �E������� ��� t Narration(��� � )Elaboration �E������� ��� J Subtype(��� � ) t Elaboration(��� � )Result �E������� ��� J cause(e , e¡ ) t Result(��� � )Explanation �E������� ��� J cause(e¡ , e ) t Explanation(��� � )Background �E������� ��� J overlap(e , e¡ ) t Background(��� � )
Theserelationsaredefinedasdefeasiblerules,where t representsadefeasibleimplication(e.g.
normally, if...,then...) governinghow eachrelationis inferred,anddescribingthe knowledgethat
is neededto infer it. In eachcasethis knowledgeis definedwith respectto an updatefunction�E������� �B� : � representsa clausein thediscourse� to which�
is related,suchthat � is updatedwith�via adiscourserelationbetween� and
�.
Thedefeasiblerule of Narrationis theleastdemanding:every clause�
maybeconnectedwith
a clause� in � via Narration. The �Bk � b��CP�. predicatein theElaborationrelationrequiresthat the
eventuality(state,eventor process)in � , e , beasubtypeof thatin�
, e¡ , suchthattheinformation
in�
extendsthat in � . In both ExplanationandResultrelations,theseeventualitiesmustbe in a
causalrelation; in the former, e¡ is the cause,and in the latter, e is the cause. In Background
relations,theseeventualitiesmustdisplaypartialoverlapin temporalorder, andat leastonewill be
astate.13It canbearguedthatrepresentingtheseknowledgebasessuffersfrom thesamecomplexity asdeterminingtheplau-
sibility of assumptions.See[Lag98] for discussion.
58
![Page 76: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/76.jpg)
In DICE, the knowledgeneededto defeasiblyassumea discourserelationmust interactwith
certain +'WU-/.C¢c.Cjq(C+ � )2. axioms,shown in Table2.17. Only thoserelationswhich areconsistentwith
theseaxiomswill be inferred. Eachaxiom expressescausalandtemporalpropertiesof eventual-
ities. £ representsa temporalorderingon eventualities;the left argumentmustprecedethe right
argument,except N e ¤£ e¡ is understoodto mean N (e ¥£ e¡ ), i.e. the left argumentmust WUT�bprecedetheright argument.NotethatCausesprecedeEffectsis anaxiomonlexical knowledge,not
discourserelations.
Table2.17:DICE: Indefeasibleaxioms
Axiom on Narration Narration(��� � ) K e ¦£ e¡Axiom on Elaboration Elaboration(��� � ) K§N e ¨£ e¡Axiom on Result Result(��� � ) K e £ e¡Axiom on Explanation Explanation(��� � ) K§N e ¨£ e¡Axiom on Background Background(��� � ) K overlap(e , e¡ )CausesprecedeEffects cause(e , e¡ ) K§N e ¨£ e¡
DICE representstheworld andlexical knowledgeneededto infer discourserelationsin terms
of defeasiblerules(calledlaws). Someexamplesareshown in Table2.18.
Table2.18:DICE: Defeasiblelaws on world knowledge
PushCausalLaw �E������� �B� J fall(x, e ) J push(y, x, e¡ ) t cause(e¡ , e )Revolt Law �E������� �B� J revolt(x, e ) J pacified(x,e¡ ) t©N overlap(e , e¡ )
Theselaws neednot be storedin the lexicon; they may be derived anew at the momenttwo
clausesareutteredandneedto beassociatedwith eachother, i.e. when � is updatedwith� 14. The
ideais that if “x revolted” is uttered,followedby “x waspacified”, thedefeasibleresult,basedon
lexical knowledgeof revolt andpacify, is thatthecorrespondingeventsdid notoverlapin time. This
resultis thenavailableto therulesandaxiomsthatproducediscourserelations.
In DICE therearealsodefeasiblelaws on discourseprocesses,which specify interactionsof
temporal,causal,andlexical phenomena,andareconsideredpartof areader’s linguisticknowledge.
Someexamplesareshown in Table2.19.14See[LA93] for referencesconcerninghow thesederivationsaremodeled.
59
![Page 77: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/77.jpg)
In StatesOverlap, the effect of a statein a discourseis described:if � and/or�
expressesa
state,thentheeventualitiesthey expresswill overlapin time. MaintainCausalTrajectoryconcerns
successionsof relations:if � is updatedwith ª relatedto�
, andit is known from context thate causede¡ , thene« can’t causee¡ . No Causerestrictstheuseof thediscourseconnective whenwith
respectto thedirectionof causalrelations.Read“ � when�
”, the law preventse from beingthe
causeof e¡ .Table2.19:DICE: Defeasiblelaws on discourseprocesses
StatesOverlap �E������� �B� J (state(e ) ¬�¬ state(e¡ )) t overlap(e , e¡ )MaintainCausalTrajectory �E������� �B� J R(� ,
�) J cause(e , e¡ ) t©N cause(e« , e¡ )
No Cause dxVA.�W�zE��� � |�tN cause(e , e¡ )DICE deductionprinciplesgoverntheinteractionbetweenthelaws andaxiomsgivenin Tables
2.16- 2.19. Theseprinciplesareshown in Table2.20. ¬¯® defineswhat canbe derived from the
defeasiblelaws andindefeasibleaxioms.Theconditions(e.g. (A1)...(A3)) mustall besatisfiedto
derive a result.
Table2.20:DICE: Deductionrules
DefeasibleModusPonens (A1) G°t²±(A2) G ¬¯®©±(A3) (not: NB± )
Complex PenguinPrinciple (B1) G¦K³±(B2) ±´t¶µ(B3) G°t· ¬¯®¸·(B4) µaK³¹(B5) ·ºK»N�¹(B6) G
Nixon Diamond (C1) ±´t´N�µ(C2) G°t²µ Not: ¬¯®©µ (or NBµ )(C3) ±(C4) G
DefeasibleModusPonensstatesessentiallythata readermayapplyany of thelaws. For exam-
ple, if a readerreadsMax fell. Johnpushedhim, andif s/hederivesthePushCausalLaw, thenthe
60
![Page 78: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/78.jpg)
conditionof that law (in this example �E������� �B� J fall( _�j`� , e ) J push({pT>VyW , _�j`� , e¡ )) is G , and
the resultof that law (cause(e¡ , e )) is ± , andso long asthe readerdoesnot know N G (thatMax
did not fall), s/hemaydefeasiblyderive ± (thatthereis a causalrelationbetweenthetwo clauses).
Deriving thePushCausalLaw requiresinformationfrom thelexicon to supportthecausalrelation
between“to push” and“to fall”. Furthermore,theaxiom CausesprecedeEffectsaxiom mustnot
be violatedby knowledge,for example,that the falling precededthepushing.Once ± is derived,
DefeasibleModusPonenscanbeusedagainto derive a Explanationrelationfrom thedefinitionof
Explanationrelationsgivenin Table2.16.
DefeasibleModus Ponenswill also allow the derivation of a Narrationrelation; in fact, an
Explanationrelationlogically entailsa Narrationrelation,for the conditionsfor a Narrationrela-
tion ( �E������� �B� ) area subsetof theconditionsfor anExplanationrelationsaresatisfied( �E������� �B� Jcause(e¡ , e ) ).
However, theAxiom on NarrationrequiresMax’s falling to precedeJohn’s pushinghim, while
the Axiom on Elaboration(and the CausesprecedeEffectsaxiom) requiretheseeventsto occur
in theoppositeorder. Complex PenguinPrincipleresolvestheseinconsistencies,by statingthat if
thereareconditionsof a law or discourserelationthatlogically entailtheconditionsof anotherlaw
or discourserelation,but otherlaws of discourserelationsmake thetwo relationsinconsistent,the
rule with themostspecificconditionswins: in this case,Explanation,because(B1) is satisfiedby
theconditionson Explanationentailingtheconditionson Narration,(B2) and(B3) aresatisfiedby
theconditionson Narrationdefeasiblyimplying a Narrationrelation,andtheconditionson Expla-
nationdefeasiblyimplying an Explanationrelation,respectively. (B4) and(B5) aresatisfiedby a
theAxiom on Narrationindefeasiblyimplying oneeventordering,andtheAxiom on Explanation
indefeasiblyimplying thenegationof thateventordering. (B6) is satisfiedbecausetheconditions
for anExplanationhold,andthereforeanExplanationrelation,but notaNarrationrelation,holds.
Nixon Diamondrepresentsincoherentdiscourses,by forbiddingtheassumptionof a law or dis-
courserelationif it resultsin adirectcontradictionwith anotherassumedlaw or discourserelation.
For example,if a Resultrelationis inferredbetweenthefirst two clausesin (2.86),thentheMain-
tain CausalTrajectorylaw (C1) on discourseprocessesassumesthethird clausecannotalsobethe
61
![Page 79: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/79.jpg)
causeof thesecondclause,so if an Explanationrelation(C2) is inferredbetweenthe secondand
third clauses,incoherenceresults.Assumingtheconditionsof bothrulesaresatisfied(e.g.thetrip-
ping, falling, andpushingoccurred),Nixon Diamondrequiresthatcausality(or lack of it) between
Max falling andJohnpushinghim cannotbeestablished.
(2.86)JohntrippedMax. Max fell. Johnhadpushedhim.
2.6.5 Extending the Theory to CognitiveStates
DICE consistsof amodalpropositionallanguageaugmentedwith t , defeasibleimplication,which
computesdiscourserelationsin anSDRSfrom thecompositionalsemanticsof its clauses.However,
DICE doesnothavefull accessto theformallanguageof SDRSs,only to theform of theinformation
it contains.Theconditions(topic-hoodanddiscourserelations)of anSDRSK aretranslatedinto
predicatesof thepropositionvariable � ,where� labelsK .
[LA99] notethat if DICE did have full accessto the languageof SDRSs,discourseinterpreta-
tion would be undecidable,becauseit computesdiscourserelationsusingreasoningaboutpartial
informationin a modalpropositionallanguage,while thelanguageof SDRSsis first order. To per-
form consistency checksoverafirst orderlanguage,DICE wouldalsohave to befirst order, andthis
wouldmake discourseinterpretationgo beyondwhatis recursively enumerable.
Thesamereasoningleadsthemto claimthatthelogic usedfor computingbeliefsandintentions
mustalsobe“shallower” thanthe logic thatmodelstheir content;becauseonelacksdirectaccess
anotherperson’s cognitive state,default reasoningis necessaryand thus consistency checksare
needed.
Like in DICE, [LA99] usea modalpropositionallanguageaugmentswith t to computecog-
nitive states. The propositionalvariablesin this languageare indexed to cognitive statesand to
discoursecontent;In DICE, the conditionsof an SDRSK are translatedinto predicatesof the
propositionvariable � ,where � labelsK , andin the languagefor computingcognitive states,the
propositionalvariable P is indexed to � . Thenan interpretationin the languagefor computing
cognitive statesis j/-`_¼+#(�(�+ � )2. only if the worlds assignedto PA arealso the onesthat make ½¦ true. Modal operatorsB(believes)andI(intends)operateover P . B ¾C¿�À correspondsto S believing
62
![Page 80: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/80.jpg)
thecontentrepresentedin theSDRS½Á . Theauthorsassumethatif S intendsthiscontent,hedoes
notalreadybelieve it is true,i.e. I ¾ PA ÂK»N B ¾ PA .
Defeasibleprinciplescan then accountfor links betweencognitive statesand the contentof
clausesin dialogue.For example,a principleof “Cooperativity” statesthatH will normallyadopt
S’sgoals;if notH will normallyindicatethis to S, i.e.:
I ¾ �¥t I ÃÄ�(I ¾ ��JÅN I ÃÆ� ) t I ÃÈÇ ¾ N�É�ÃÄ�As [GS86] note,thepossiblegoalsa speaker mayhave areinfinite. [LA93] notehowever that
certaintypesof speechactshave goalswhich onecancompute;for example,thegoalof a speaker
saying(representedwith :) a question(representedwith ?� ) is to know ananswer(representedas�), i.e.:
S:?�Êt ( N B ¾ � J I ¾yǺ¾ � |Similarly, Grice’s maxims15 suchas“Be Sincere”,andactionsto achieve goals,suchasPrac-
tical Syllogism(i.e. If S intends� andbelievesthat�
normally implies � thenS intends�
), can
be representedas defeasibleprinciples,enablingthe reasoningbetweencognitive statesand the
informationalcontentof clauses.
2.6.6 Summary
In this section,we presentedan alternative theoryof discoursecoherence,onewhich modelsdis-
coursecoherencewithout invoking the notion of a discoursetreestructure. The theory replaces
syntacticstructureof discoursewith a structuredsemantics.Vendler’s characterizationof abstract
objectreferencewaspresentedandextended,andits majordivisionswereshown capableof being
modeledin SDRT asreferenceto substructuresor eventvariables.Thetheoryfurthermodelsworld
knowledgeandthe inferenceof propositionalrelationsin termsof indefeasibleaxiomsanddefea-
sible rules. Interactionof the structuredsemanticsandinferencesystemis regulatedby relation-
specificformal rulesof construction,and the availability of anaphoricreferenceis dependenton
15We will discussGrice’s maximsin detail in Chapter5.
63
![Page 81: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/81.jpg)
relationsandthestructuresthey create.Thetheoryfurtherextendsitself to theinferenceof cogni-
tivestates,therebymodelingthelinks betweeneverymajorcharacterizationof discoursecoherence
thatwe have sofarseenin thischapter.
2.7 Discussion
Sofarin thischapter, wehaveoverviewedhow avarietyof discoursemodelscharacterizeall or some
part of discoursecoherence,andhave summarizedwhat they do anddon’t do in relationto other
models.In this section,we discussunresolved issuespertainingto theapproachof thesemodelsto
discourseanaphoraanddiscourserelations,andpresentanew modelof a rich intermediatelevel of
discourse,which providesa meansof resolvingthe issuesposed,while leaving a numberof open
questions.In subsequentchapterswe undertake the processof answeringsomeof the remaining
openquestions.
2.7.1 Proliferation of DiscourseRelations
As [Keh95] notes,in 1748,[Hum48] discernedthreebasicconnectionsthatcanexist betweenideas:
Resemblance, Causeor Effect, and Contiguity (in time or place). Sincethen, as we have seen
in the prior sections,many alternative waysof categorizing the atomicsetof discourserelations
have beenproposed.[Lon83] and [MT88], for example,eachprovide a uniquecharacterization
of the “deep” semanticrelationsbetweenpropositionsthat underliethe surfacestructureof text.
[MT88]’s characterization,whichis alsointendedto cover presentational,or intentional,relations,
is flexible aboutthe numberandtype of possiblerelationsthat exist. In both of thesetheoriesit
is arguedthatmorpho-syntacticcuesdo not reliably indicatethesediscourserelations.[HH76], in
contrast,deriveswhatheclaimsto beacomplete,thoughdifferent,setof semanticrelationsbetween
propositionsfrom the“surfacecues”availablein a text. [Mar92] combinesthetwo approachesto
derive yet anothersetof discourserelations,by claiminga “deep” relationexists at a placein the
text if an explicit surfacecuecanbe insertedthere. Theapproachtaken by theseauthorstowards
defininga usefulsetof discourserelationsis different thanthe approachtaken by the remaining
authorssurveyed in this chapter, in that theformeraim to describethepossiblediscourserelations
64
![Page 82: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/82.jpg)
thatcouldexist in atext in termsof theirown intuition. Clearly, their intuition displaysasignificant
degreeof variation.
On theonehand,as[Keh95] notes,many of thesevariationscanbeviewed asterminological
variantsof eachother. And as[Kno96] notes,someflexibility is desirable,at leastuntil aparticular
set of relationsis proven useful and possiblyeven to allow for languageevolution. Moreover,
certainrelationsmayprovemoreusefulin somedomainsthanothers,andeachsetis not in all cases
claimedto cover exactly thesamerangeof discoursecoherence,or applyto thesameconstituents,
astheothers.[Kno96] providesa usefulcomparisonof a numberof differentsets,includingthose
overviewedin thischapter.
On the other hand,as ([Keh95]) notes,the variation illustratesa commonobjection to this
“laundry-list” approachto understandingdiscoursecoherence:without an explanatorybasisfor
producingand constrainingthe productionof a particularset of atomic discourserelations,and
a characterizationof how more complex relationscan be derived from them, it is impossibleto
objectively selectoneparticularsetover any other. For example,in suchan approach,it would
beentirelypossibleto claim theexistenceof a relationdefinedexplicitly for (2.87). As ([Kno96])
definesit, sucha relationcouldbecalled: inform accidentand mention fruit .
(2.87)Johnbroke his arm. I like plums.([Kno96, 35])
Thus, while the “laundry list” approachis useful for perceiving the range of ways in which
constituentsarerelatedin coherentdiscourse,anapproachthatdescribesthemechanismsinvolved
in deriving, constraining,andcombiningdiscourserelationspotentiallyhasthe additionalbenefit
of yielding a distinctionbetweenthe differentkinds of discourserelations,andconstituents,that
shouldbeassociatedwith eachmechanism.
This is theapproachto modelingdiscoursecoherencetakenby theremainingauthorsdiscussed
in this chapter;their associationof discourserelationswith mechanismslikely explainswhy these
modelsmakeuseof asignificantlysmallernumberof discourserelationswhendescribingthemech-
anismsassociatedwith themthando thepurelydescriptive models.Nevertheless,therecontinues
to beconsiderablevariationin thenumberandtypeof discourserelationsthesediscoursemodels
defineaswell. As we saw in prior sections,[Hob90] associatesfour propositionalrelationswith
65
![Page 83: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/83.jpg)
a processof discourseinference,[Keh95] reducesthis set to three,anddefinesthemin termsof
constraintswhich [HSAM93]’s inferencesystemdeterminessatisfiedor not. [SSN93]focuson the
cognitive resourcesunderlyingtheproductionof intentionalandpropositionalrelations,identifying
themwith four underlyingfeatures.[GS86] allows for an infinite numberof intentionalrelations
betweendiscoursesegments,while distinguishingonly two structuralrelations,andtwo proposi-
tional relationsbetweeninformationconveyed by segments.[Pol96] distinguishesthreestructural
relationsbetweendiscourseunits, andan unspecifiednumberof propositionalrelations. [LA93]
associatesfivepropositionalrelationswith arule-basedlogic for discourseinference,andaninfinite
numberof intentionswith arule-basedlogic for inferringcognitive states.Moregenerally, [Hov90]
surveys over350differentdiscourserelationsthathave beenproposedin theliterature.
2.7.2 Useof Linguistic CuesasSignals
The argumentagainstusingexplicit “cue phrases”assignalsof discourserelationsbetweendis-
courseunits (generallydefinedasclausesandsequencesof clauses),hastwo parts.First, a single
cuephrasemaynot unambiguouslysignala singlediscourserelation. For example,thecoordinat-
ing conjunction,and, notoriouslyplacesvery few constraintson thediscourserelationthatcanbe
derivedbetweentheclausesit connects.Second,thepresenceof thesecuephrasesis notobligatory;
discourserelationscanbederived in anappropriatecontext whentheassociatedcuephraseis not
present.[Mar92]’s insertiontestprovidesa resolutionfor thesecondargument,but not theformer.
Nevertheless,many cuephrasesaresoclearlyassociatedwith discourserelations(e.g.“as a result”K Resultrelation)that,aswe saw, mostof the mechanism-basedmodelsmake useof or at least
acknowledgethis association.For example,even thoughRST’s authorsargueagainstthe useof
cuephrasesassignalsof RSTrelations,extensionsof RST[Mar00,Mar97, SdS90]haveshown that
linguistic cuescanbeusedto manuallyandautomaticallylabelRSTrelations.
Thereis in facta wealthof literatureconcerningthedifferentwayscuephrasescanbeusedto
signalboth propositionalandintentionalrelations. [Coh84], for example,arguesthat cuephrases
can function to reducethe processingload on the hearerand facilitate recognitionof the argu-
mentstructureof a discourse.[EM90] identifiesandassociatespragmaticfeatureswith a variety
66
![Page 84: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/84.jpg)
of cuephrasesandshows thatthesefeaturescanbeusedto implementtheuseof cuephrasesin an
argumentation-basedtext generationsystem.[Hov95] arguesthatcuephrasescansignalin parallel
semantic,goal-oriented,attentionalandrhetoricaldiscourserelations,all of which canpotentially
yield distinct structuralanalyses;the speaker mustselectthosewhich minimize the overall struc-
tural ambiguityfor thehearer. [Bla87] arguesthatcuephrasesindicatehow therelevance[SW86]
of onepropositionis dependenton the interpretationof another. In [Sch87]’s multi-dimensional
discoursemodel, cue phrasesindex eachutteranceto the speaker and heareralong a variety of
pragmaticandsemanticplanesin the surroundingdiscourse.[Fra88, Red90, vD79] characterize
how a varietyof cuephrasessignalpragmaticandpropositionalrelations.[MS88, LO93] provide
a detailedinvestigationof the formal semanticsof temporalcuephrases,and[Lag98] providesa
detailedinvestigationof theformal semanticsof causalcuephrases.
Building on thesesemanticinvestigations,[Kno96] developsa theoryof coherencerelations
which providesbotha solutionto theproblemthatcuephrasesaren’t reliablebecausethey canbe
ambiguous,anda solution to the problemof the proliferationof discourserelations. Knott first
definesan intuitive test to isolatea corpusof cuephrases.Humanannotatorsusethe test,which
isolatesevery phrasethatmodifiesa clauseor sentencein a naturally-occurring text, togetherwith
its host clause. If the humansjudge that the isolatedunit cannotbe interpretedwithout further
context, but canbe interpretedif the selectedphraseis removed, then the phraseis a cuephrase
(discourseconnective). Knott’s corpuscontainscoordinatingandsubordinatingconjunctions,anda
widevarietyof prepositionalandadverbialphrases,in additionto asmallnumberof relative clause
markersandotherphrasesthattake sententialcomplements.
Drawing on [Mar92]’s insertiontest,Knott thenusesa substitutiontestto organizethecorpus
into ahierarchicaltaxonomy. Thetestselectscontexts in whichacuenaturallyoccurs,andareader
decidesif thatcuecouldbereplacedwith anothercuein thosecontexts withoutchangingthemean-
ing of the discourse.By testinga variety of cuephrasesin a variety of contexts, a hierarchical
taxonomyis formed,in whichany cue � canbecharacterizedassynonymouswith, a hypernym of,
ahyponym of, exclusive with, or contingentlyinter-substitutablewith any othercue � .By investigatingtheinter-substitutability contextsanddrawing [SSN93]’scognitiveapproachto
67
![Page 85: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/85.jpg)
discourserelationsandthesemanticsof cuephrasesmentionedabove, Knott defineseightbinary-
valuedcognitive featuresthatcharacterizethepossiblediscourserelationsandassociatesthelexical
semanticsof cuephraseswith valuesfor thesefeatures,by interpretingthetaxonomye.g.asfollows:
if twocuesaresynonymous,thenthey sharethesamevaluesof all features;if twocuesareexclusive,
thenfor at leastonefeaturethey take oppositevalues;if a cue � is a hypernym of � , then � shares
the valueof � in all featuresfor which � is defined,but additionallyhasa value in a featurefor
which � is notdefined,etc.Featurevaluesfor threeconnectivesareillustratedin Table2.21.
Table2.21: [Kno96]’s Featuresof DiscourseConnectives
Feature DiscourseConnectiveasa result unfortunately furthermore then
Sourceof Coherence semantic semantic pragmatic –Anchor of Relation cause resultPattern of Instantiation bilateral unilateral unilateralFocusof Polarity counterpartPolarity of Relation positive negative positive positivePresuppositionality non non nonModal Status actual actual actual –Rule Type causal causal ind?
An undefinedfeaturevalueis representedas“–”; anuncertainvalueis representedwith ablank
cell, anda“?” indicatesthatthevalueis likely but requiresfurtherstudy. The“sourceof coherence”
featurerepresentswhetherthe semanticsof the connective assertsthat the readeris intendedto
believe that the relation holds (semantic)or world knowledgealreadyindicatesthat the relation
holds(pragmatic).Theremainingfeaturesrelateto Knott’s argumentthatevery discourserelation
betweentwo discoursespansA andB correspondsto thefilling outof oneof two typesof defeasible
rules,causalor inductive (i.e. generalizations),specifiedby the“rule type” feature.Theserulesare
of the form: P1 J ... J Pn K Q. The remainingfeaturesspecifyhow theserulesarefilled out,
i.e. which span(A or B) yields P andhow, andwhich spanyields Q andhow. For example,the
“anchor” featuresrepresentsthefact thatA correspondseitherto someP (cause)andis known, or
Q (result)andis desired.The“patternof instantiation”,“focus of polarity” and“polarity” features
roughly indicatewhetherC or its negationis on the sameor oppositesideof the rule asA or its
68
![Page 86: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/86.jpg)
negation. The “presuppositionality” featureindicateswhetherprior context is alsoinvolved in the
relationassomeP, andthe“modal status”featureindicateswhetherthis context is known (actual)
or not (hypothetical)by thereader.
2.7.3 Structural and Anaphoric CuePhrases
DLTAG [FMP�
01, CFM�
02, WJSK03,WKJ99, WJSK99,WJ98] proposesadiscoursemodelthat
will provide thefoundationfor thestudiesin theremainderof this thesis.TheDLTAG modelincor-
poratesmany of the insightsof themodelsandinvestigationsdiscussedabove, but it alsodisplays
somesignificantnovel insightsthat enablethe incorporationinto the modelof viable solutionsto
boththeproliferationof discourserelationsandtheambiguityof cuephrases,andtheincorporation
of solutionsto otherproblemsnotpreviously addressedby othermodels.
At thecoreof DLTAG is the insight thatdiscourseconnectivescanbemodeledaspredicates,
akin to verbsat the clauselevel, except that they can take clausesas their arguments. DLTAG
[FMP�
01] currentlymodelsthis syntaxusingthestructuresandstructure-building operationsof a
lexicalizedtree-adjoininggrammar(LTAG )[JVS99], which itself is anextensionof TAG [Jos87],
andis widely usedto modelthesyntaxof sentences.Wewill presenttheLTAG andDLTAG models
in detailin Chapter4, andasyntax-semanticinterfacefor DLTAG will bediscussed,drawing onthe
discourse-level interfacepresentedin [Gar97b] andthesentencelevel interfacepresentedin [KJ99].
Briefly, in a lexicalizedTAG, therearetwo typesof elementarytrees:initial treesthatencode
basicpredicate-argumentrelations,andauxiliary treesthatencoderecursion.Eachelementarytree
hasat leastoneanchor: the lexical item(s)with which it is associated.A lexicalizedTAG pro-
videstwo structurebuilding operationsto createcomplex trees:substitution(indicatedby Ë ) and
adjunction(indicatedby Ì ).In DLTAG, theanchorfor anelementarytreemaybea cuephraseor a featurestructurethat is
lexically null, in whichcaseaninferredrelationmayberepresentedin termsof [Kno96]’s features.
DLTAG distinguishesthreetypesof elementarytreestructures,exemplifiedin Figure2.15with cue
phrasesasanchors.As thefigure exemplifies,subordinatingconjunctions(e.g. because), coordi-
69
![Page 87: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/87.jpg)
natingconjunctions(e.g. and)16, and lexically null featurestructuresaremodeledas“structural
connectives”, i.e. predicatesthat retrieve both argumentsstructurally. The semanticsassociated
with thesecuephrasesandtheir argumentscanbecomputedcompositionally.Í Í Í ÍÎÎÎÎË because Ë � � ����Ì and Ë Ï ÏÐÐasa result Ì
Figure2.15:ElementaryDLTAG Trees
Adverbials(e.g. as a result), on the otherhand,aremodeledas“anaphoricconnectives”, i.e.
predicatesthat retrieve only oneargumentstructurally, the discourseunit they modify. The other
argumentmustbe retrieved anaphorically. The semanticsassociatedwith thesecuephrasesand
their argumentscannotbe fully computeduntil the anaphoricargumentis resolved. To attachto
the growing discoursetree, they mustadjoin to the right argumentof a structuralconnective. If
no overt structuralcue phraseis present,the structuralargumentof the adverbial is attachedto
the discoursestructurevia a lexically-emptyelementarytreestructurallyidentical to the tree for
and in Figure2.15,which conveys continuationof thedescriptionof the larger treeto which it is
attached.Althougha morespecificrelationmaybeinferredandrepresentedasfeaturesin thetree,
therelationprovidedby thesyntaxaloneis semanticallyunder-specified,analogousto thesemantics
of noun-nouncompounds.
DLTAG’sdistinctionbetweenstructuralandanaphoricconnectivesis basedonconsiderationsof
computationaleconomyandbehavioral evidencesuchasfound,for example,in thecaseof multiple
connectives([WKJ99]). In (2.88),taken (in simplified form) from [CFM�
02], becauseencodesa
causalrelationbetweentwo eventualities,Q = RAISE IRE (SALLY, FRIENDS) andR = ENJOYS
(SALLY, CHEESEBURGER), andneverthelessencodesa violatedexpectationrelationbetweenR =
ENJOYS (SALLY, CHEESEBURGER) andP = SUBSCRIBES (SALLY, VEGETARIAN TIMES).
(2.88a)Sallysubscribesto VegetarianTimes.
(2.88b)Lately, she’s raisedtheire of herveganfriends
(2.88c)becausesheneverthelessenjoys theoccasionalbaconcheeseburger.
16This view will befurtherqualifiedin Chapter4.
70
![Page 88: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/88.jpg)
To modelbothpredicatesstructurallywouldcreateadirectedacyclic graph,whichgoesbeyond
thecomputationalpowerof LTAG andcreatesacompletelyunconstrainedmodelof discoursestruc-
ture [WJSK03]. However, preliminary investigationsinto the behavior of cuephrasesreveal that
while subordinatingandcoordinatingconjunctionsseemto alwaysandonly takeadjacentdiscourse
segmentsastheir arguments,adverbial cuephrasesseemto sharemany propertieswith anaphora.
For example,their left argumentmay be found intra- or inter-sententially, asshown in (2.89)and
(2.90),respectively. Moreover, their left argumentcanbeaninferredsituation,asshown in (2.91)
(thesituationin which theaddresseedoesnot wantanapple),andit canevenbederived from the
interpretationof a discourserelationbetweentwo segments,asshown in (2.92)(theresultrelation
impartedby so).
(2.89)A personwhoseeksadventuremight, for example,try skydiving. [[WJSK03]]
(2.90)Somepeopleseekadventure.For example,they might try skydiving. [[CFM�
02]]
(2.91)Do youwantanapple?Otherwise,youcanhave apear. [[WJSK03]]
(2.92)Johnjustbroke his arm.So,for example,hecan’t cycle to work now. [[WJSK03]]
DLTAG doesnot claim to provide a completemodelof discourse;it is not committedto the
view of theentirediscourseasasingletree,treestructuresmayonly bebuilt within segments(akin
perhapsto [KOOM01]), andmultiple treesmay be possible,for exampleat an informationaland
intentionallevel, as[MP92] have shown. While DLTAG is not committedto a particularview of
discoursestructure,it is very committedto the idea that a rich intermediatelevel betweenhigh-
level discoursestructureandclausestructure,namely, thesyntaxandsemanticsassociatedwith cue
phrases,mustbe specifiedand recoverablein order to interpreta discourse.Moreover, because
cuephrasesaresomeof theclearestindicatorsof discoursestructure,andtheir argumentscanbe
reliably annotated[CFM�
02], large-scaleannotationstudieswill provide information about the
rangeof possiblediscoursestructures.
2.7.4 Comparison of DLTAG and Other Models
Unlike thediscoursemodelsdiscussedin prior sections,DLTAG doesnot claim to provide a com-
pletemodelof discourse.Rather, it proposesanintermediatelevel of discoursestructureandinter-
71
![Page 89: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/89.jpg)
pretationthatcanbebuilt directlyon topof theclausestructureandinterpretation.BecauseDLTAG
builds a treestructurefor discourse,it is similar in computationalpower to theothertree-baseddis-
coursegrammarsdiscussedin this chapter. But althoughDLTAG, like many othermodels,argues
that(anintermediatelevel of) discoursecanbemodeledin termsof syntaxandsemantics,DLTAG
alonedefinesthis discoursestructureandinterpretationin termsof thesamemechanismsthatare
alreadyusedat the sentencelevel. Moreover, DLTAG alonearguesthat not all relationscanbe
modeledstructurallyin a tree-baseddiscoursemodel;DLTAG decouplesanaphoricandstructural
connectionsbetweendiscoursesegments,andthusonly theDLTAG treeis ableto modelrelations
betweenadiscoursesegmentandmultiple prior segmentswithin asingletree.
Othertree-basedmodelsalsointroduceunnecessaryredundancy in termsof theadditionalmech-
anismsthey proposeto build discourse.Thesemodelsmake useof a predefinedsetof discourse
relations,andcuephrasesaretreatedas“signals” of thesepredefinedrelations. The dependency
of theserelationdefinitionson thepresenceor inferenceof a cuephraseis clearlyvisible, suchas
the “otherwise” relationproposedin RST[MT88]. Numerousotherexamplesof this arefound in
[Mar97]’s instructionsfor manuallylabelingRSTrelations.However, if, asin DLTAG, thesyntax
andsemanticsof cuephrasesare taken into account,then it is redundantto postulateadditional
relationdefinitionsandgrammaror semanticrulesto creatediscourserelations.Moreover, theRST
manualalsoillustratescaseswherediscourserelationsbetweendiscoursesegmentsareredundant
even in the absenceof a cuephrase.As illustration, in (2.93)-(2.95)(from [Mar97]), a discourse
deictic(italicized)in (b) refersto (a),andits predication(bold-faced)is synonymouswith theRST
relation(capitalized)between(a) and(b) (orderis representedby W (nucleus)and ( (satellite)).
s INTERPRETATION n
(2.93a) All evidencepointsto thefactthatKennedywasassassinatedby theCIA.
(2.93b) Thissuggeststo me thattheorganizationis untrustworthy.
n EXPLANATION-ARGUMENTATIVE s
(2.94a) Mostof thedinosaursdiedabout65,000,000yearsago.
(2.94b) Someresearchersassumethattheimpactof abig meteoritecausedthis.
72
![Page 90: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/90.jpg)
n EVALUATION s
(2.95 a) Featureslike our uniquelysealedjacket andprotective hub ring make our discslast
longer. And oursoft innerliner cleanstheultra-smoothdiscsurfacewhile in use.
(2.95b) It all addsup to betterperformanceandreliability.
[KOOM01] suggestthat discoursedeixis useis not a discourserelation,but rathera form of
“resumption”. However, their dataonly containscasesconcerningthe RST elaboration object-
attrib ute relation. In thefollowing examplesfrom [Mar97], we find similar redundancy, although
thereis no discoursedeixis, but rathera nominal referencein (a) to a noun in (b). Again, the
predicationand/orreferenceis synonymouswith thelabeledRSTrelation.
n/sCAUSE-RESULT n/s17
(2.96a) Unfortunatelyfor the athlete,the anaerobicmetabolismof carbohydratescanyield a
buildup of lactic acid,whichaccumulatesin themuscleswithin two minutes.
(2.96b) Lacticacid andassociatedhydrogenionscauseburningmusclepain.
n INTERPRETATION s
(2.97a) Steepdeclinesin capitalspendingcommitmentsandbuilding permitspushedthelead-
ing compositedown for thefifth time thismonth.
(2.97b) Such a declineis unusualat this stagein anexpansion.
n EVALUATION s
(2.98a) Policy makershave four options...
(2.98b) Thelastof theseis ultimately the only sustainableoption.
ELAB n PROC-STEPs
(2.99a) A usershouldinvoke theprogramwith thenameof thefile andthenameof thefile to
becreated.17[Mar97, 24] statesthatthewriter’s intentionsareunclearasto whetherthiscauseor this resultis thenucleus.
73
![Page 91: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/91.jpg)
(2.99b) Theprocessopenstheexistingfile, createsthenew file, andcreatesachild process.
WhattheRSTrelationsin theseexamplesdo is simply restatetheclause-level semantics,rather
thandescribenew informationaboutthelink betweentheclausesthat is not alreadyrepresentedin
thesemanticsof theclauseitself. Becausemostof themodelsdiscussedabove do not incorporate
clauselevel semanticsinto their discourseinterpretation,they are likely to postulatewhat is in
facta redundant“discourserelation” in suchcases.But becauseDLTAG builds discoursestructure
directly on top of clausestructure,this semanticsis available to the discourseinterpretation;in
DLTAG the “relations” between(a) and(b) in theabove caseswould be representedby an empty
connective, signaling“continuation”of thediscourse.By retainingthesemanticinterpretationsof
theclausesandtheinformationabouthow thereferentiallinks betweenthemareresolved,theneed
to supplyanadditionalRST-typerelationis removed.
Themodelsof inferencediscussedearlierin this chapteralreadymake someuseof theseman-
tic contributionsof somecuephrases.[HSAM93], for example,mentionusingthe propositional
contentof because, and[GS86]mentionusingthepropositionalcontentof but. SDRT [LA93] also
incorporatesthesemanticcontributionsof somecuephrasesinto their structuredsemanticsandin-
ferencesystem,anddoesallow multiple relationsbetweendiscoursesegments,but its useof only
structuralattachmentsandpredefineddiscourserelationsagainproducesredundancy. For example,
theassociationof a structural“result relation”with anadverbialcuephrasesuchasasa resultwill
be shown in Chapter3 to be redundant.In fact, aswill becomeapparentafter the discussionin
Chapter3, SDRT canalreadyhandlethesemanticsof adverbial cuephrasesby extendingto them
thesemanticsthey employ for discoursedeixis.Moregenerally, anincorporationof thesemanticsof
all discourseconnectiveswould likely reducethecomplexity of inferencesystems;if thesemantics
of a connective canasserta relationbetweenclauses,this relationno longerneedsto beinferred.
[Kno96]’s proposalto decomposediscourserelationsinto featuresthat are attributed to the
semanticsof cuephrasesis model-independentandthuscanbeincorporatedinto DLTAG.However,
thereare a numberof problemsmainly resultingfrom his useof an intuitive test to isolatecue
phraseswhich must first be resolved. For example,Knott’s list includeslexical items from all
five syntacticcategoriesoriginally notedby [Qui72] ascontainingcuephrases:coordinatingand
74
![Page 92: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/92.jpg)
subordinatingconjunctions,adverb and prepositionalphrases,and phraseswhich take sentential
complements(e.g. it follows that, all told). If the interpretationof verbsand small clausesare
availableto thediscoursemodel,asis thecasein DLTAG, thenattributing themadditionalfeatures
of adiscourserelationbecomesredundant;any presuppositionsof theseverbs(e.g.thatif x follows,
then � follows something) will alreadybe available at clauselevel. Similarly, Knott’s intuitive
testoverlooksthe fact that the semanticsof complex cuephrasescanbe treatedcompositionally.
For example,his list includescomplex relative clausecomplementizers(e.g. especiallywhich), as
well ascomplex subordinatingconjunctions(e.g. especiallyif/when,even if/when,only if/when,
etc). Adverbssuchasespecially, even,only canattachto many cuephrases;listing eachresulting
combinationindividually is unnecessaryif thecompositionalsemanticsof cuephrasesis takeninto
account.Moreover, like verbsandsmall clauses,if thesemanticsof complementizersis available
to thediscoursemodel,thenattributing themfeaturesof adiscourserelationis redundant.
Moregenerally, Knott’s intuitive testenablesothermechanismsof discoursecoherence,suchas
inference,implicature,andintonation,to be conflatedwith the semanticsof cuephrases,causing
errorsof comissionand omission. For example,Knott erroneouslyincludesunfortunately, and
surprisingly, but not unhappilyor not surprisingly. Moreover, investigationof naturallyoccurring
casesof unfortunatelyrevealsthatsomefeaturevaluesareincorrect.Inclusionof unfortunatelyas
a cuephrasewould requireit to beundefinedfor themajority of features,akin to and. While and
is clearlyuninterpretablein isolationwith its hostclause,unfortunatelyis not. In addition,Knott’s
featurescannotfully describethe idiosyncraticmeaningof eachconnective. [JR98], for example,
arguethatthefeaturesincorrectlydescribetheuseof donc(similar to therefore) in French,because
furthersemanticpropertiesof theadverbmustbetakeninto account.Finally, it is notclearwhether
Knott intendsto associateinferreddefeasibleruleswith all cuephrases;althoughthevalueof the
‘rule type’ featureis left blank for adverbial temporalconnectives(e.g. then,next), they neednot
bedefinedin relationto featurevaluesthatfill out thesemanticsof defeasiblerules.
In essence,DLTAG arguesthat it is thesemanticsof cuephraseswhich drivestheconstruction
of a discoursemeaning. Associatingcuephraseswith semanticssolves both the proliferationof
discourserelationsandtheambiguityof cuephrasesas“signals” of theserelations.It is no longer
75
![Page 93: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/93.jpg)
necessaryto “map” the useof cuephrasesto separatelydefineddiscourserelations;instead,cue
phrasessupplyrelationsin their semantics,andlike all predicates,themeaningof therelationthey
supply canbe vagueor preciserelative to other predicates,and it can also be over-loaded. For
example,the verb go at the clauselevel hasa variety of meanings,mostof which canbe stated
morepreciselyby otheractionverbs.And becauseDLTAG views inferenceasanothermechanism
separatefrom compositionalsemantics,additionalrelationscanbe inferredwhetheror not a cue
phraseis used. Incorporatingthe intermediatemoduleDLTAG proposesinto othermoduleswill
yield amorecomputationallyeconomicalandmoreobservationallyvalidcompletediscoursemodel.
2.7.5 RemainingQuestions
Becausethesemanticsof cuephrasesdrivestheconstructionof discoursemeaningin DLTAG,each
cuephrasemustbeassociatedwith asemantics.While, asSection2.7.2indicates,thesemanticsof
subordinatingandcoordinatingconjunctionshasbeeninvestigatedin greatdetailbothat theclause
anddiscourselevel, thesemanticsof mostadverbial cuephrases,consistinglargely of adverband
prepositionalcuephrases,have beenmainly ignoredat the clauselevel, andhave received much
lessattentionat thediscourselevel. Wewill seeclearevidenceof this in Chapter3.
In fact,partof this “attentioninequality” is simply dueto thefactthatthesetsof subordinating
andcoordinatingconjunctionsarerelatively small,while thesetof adverbialsis a largeset.In fact,
as[Kno96] notes,the setof adverbialsis compositional,andthereforeinfinite. For example,the
adverbgenerally canbemodifiedby innumerablymany instancesof very (e.gverygenerally, very
verygenerally,...), eachtime producinga uniquememberof this set. It is not surprising,therefore,
thatwhile DLTAG proposesthat certainadverbialsfunctionasdiscourseconnectives,they do not
isolatethis subsetfrom thesetof all adverbials. Becauseit is not possibleto answerthequestion
of which adverbialswhich functionasdiscourseconnectiveswith a list, onemustaskinsteadwhat
mechanismscauseanadverbial to functionasadiscourseconnective.
In Chapter3 we will uselinguistic theory to investigatethe semanticmechanismsthat cause
an adverbial to function asa discourseconnective. This investigationwill alsoshedlight on the
questionof whatdiscourseunitsanadverbialdiscourseconnective relates.For while thediscourse
76
![Page 94: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/94.jpg)
modelsoverviewed in this chaptermake frequentuseof eventualityinterpretationsof clauses,and
frequentuseof theterm“discoursesegment”,theseinterpretationsandconstituentsarein mostcases
not well definedor distinguishedfrom otherinterpretationsor constituents.We will usediscourse
deixis researchto betterclarify both the semanticnatureof the argumentsof adverbial discourse
connectives andthe syntacticconstituentsfrom which they canbe drawn. Our investigationwill
alsoshedlight on thespaceof discourserelationsimpartedby awidevarietyof adverbialdiscourse
connectives,andenableaprecisesemanticrepresentationof theirbehavioral anaphoricity. In Chap-
ter 4 we theninvestigatehow this semanticscanbe incorporatedinto a syntax-semanticinterface
for the DLTAG model. In Chapter5, we investigateotherwaysin which the interpretationof an
adverbialcancontributeto discoursecoherence.
2.8 Conclusion
Thediscoursemodelspresentedin this chaptergenerallyagreethatdiscoursehasa recursive struc-
ture andthat this structureaffects the interpretationof discourse.We have seena numberof ef-
forts to formalizetheseinsights,including descriptive, inference-based,syntacticand/orsemantic
approachesto modelingdiscourserelationsand anaphoricconstraints. We have arguedthat the
DLTAG approachshouldbeincorporatedinto thesemodels,therebyremoving theneedto selecta
singlesetof “primiti ve” relationsunderlyingall coherenttext spans,anda singlemechanismfor
producingthem. In DLTAG’s view, thesyntaxandsemanticsof cuephrasesprovidesoneway of
producingcoherencebetweendiscourseunits,anddiscourseinferenceprovidesanother. By under-
standinghow differentmodulesinteractwith eachotherandwith othercharacteristicsof discourse
to producecoherence,we canthenbegin to understandhow completeandcoherentdiscourseinter-
pretationsareproduced.
77
![Page 95: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/95.jpg)
Chapter 3
SemanticMechanismsin Adverbials
3.1 Intr oduction
In Chapter2, we describedsimilaritiesanddifferencesbetweena variety of modelsof discourse
coherence,which, takentogether, distinguishdifferentmodulesrequiredto build a completeinter-
pretationof discourse.We introducedDLTAG ([FMP�
01, CFM�
02,WJSK03,WKJ99,WJSK99,
WJ98]) asa theorythatbridgesthegapbetweenclauseanddiscourseinterpretations,by usingthe
samesyntacticandsemanticmechanismsthatbuild theclauseinterpretationto build anintermediate
level of discourseinterpretationon topof theclauseinterpretation.
In DLTAG, cuephrases, or discourseconnectives, arepredicates,like verbs,except they can
take interpretationsof clausesas arguments. For coordinatingand subordinatingconjunctions,
both argumentscomestructurally. For adverbial cuephrases,which aremainly adverb (ADVP)
andprepositional(PP)phrases,only oneargumentcomesstructurally. Basedon considerationof
computationaleconomyandbehavioral evidence,DLTAG arguesthat theotherargumentof these
adverbialsmustbe resolved anaphorically. However, while DLTAG proposesthat certainadver-
bialsfunctionasdiscourseconnectives,it doesnot isolatethis subsetfrom thesetof all adverbials.
Becausethesetof adverbialsis compositional,andthereforeinfinite ([Kno96]), it is not possible
list theadverbialsthatfunctionasdiscourseconnectives.In thischapter, wepresentacorpus-based
investigationof the semanticmechanismsthat causecertainadverbials,which we call discourse
78
![Page 96: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/96.jpg)
adverbials,to functionasdiscourseconnectives,while otheradverbials,which we call clausalad-
verbials,do not functionasdiscourseconnectives.
In Section3.2we review thefunctionandstructureof adverbialsanddescribehow theseprop-
ertieswereusedto extracta datasetfrom a parsedcorpora.In Sections3.3-3.4we overview major
syntacticandsemanticissuesthathave beenaddressedin clause-level analysesof adverbials,and
introduceanextensionto theseanalysesthat incorporatesthediscoursedeixis researchintroduced
in Chapter2 anddefinesthe propertiesof semanticobjectswhoseanaphoricitycancauseadver-
bials to function as discourseconnectives. Following DLTAG, in this extension,anaphoricityis
definedastheuseof “discourseconnecting”devicessuchasanaphoricreferenceandpresupposi-
tion by adverb andprepositionalforms to retrieve objectsat the discourselevel, just as they are
employedfor theretrieval of objectsat theclauselevel. In Sections3.5-3.6,we incorporateinto this
extensiondiscourse-level analysesthathave alreadybeenproposedfor a smallvarietyof adverbial
discourseconnectivesandpresenta rangeof semanticobjectsthatcomposeadverbialsanda range
of anaphoricdevices that determineif andhow theseobjectsrelateto the surroundingdiscourse.
Weconcludein Section3.7.
3.2 Linguistic Background and Data Collection
This sectionprovidesthe linguistic backgrounduponwhich thestudiesin subsequentsectionsare
built. We first discusswaysin which adverbial functiondiffers from otherfunctionsof ADVP and
PPandreview thegrammaticalstructureof ADVP andPPadverbials.We thendescribehow these
propertieswereusedto extractthedatasetstudiedin this thesisfrom acorpusof naturallanguage.
3.2.1 Function of Adverbials
Adverbialsareadjuncts, elementswhosepresencein a clauseis not obligatoryfor clauseinterpre-
tation. They functionasmodifiers, elementsthat supplyadditionalinformationabouttheelement
they modify. Adverbialsfrequentlymodify verbphrases(VP) or sentences(S).
The term adverbial denotesa functional ratherthan a syntacticcategory. As exemplified in
(3.1)-(3.8),avarietyof syntacticcategoriescanfunctionasadverbials:in additionto ADVP andPP
79
![Page 97: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/97.jpg)
(3.1)-(3.2),which arethefocusof this thesis,finite clauses(3.3),non-finiteclauses(e.g. infinitives
(3.4),-ing participles(3.5),-edparticiples(3.6)),verb-lessclauses(3.7),andnounphrases(3.8)can
alsofunctionasadverbials([Ale97]).
(3.1)Hopefully, therewill never beanotherworld war.
(3.2) In mostsituations, Johnremainscalm.
(3.3)Johnworkedlatealthoughhewasverytired.
(3.4)Johnplaysto win.
(3.5)Reading, Johnrelaxes.
(3.6)Urgedbyhis mother, Johndid thedishes.
(3.7)Johnraninto thestreet,unaware of thedanger.
(3.8)JohncameTuesday.
ADVP andPPdo not alwaysfunctionasadverbials;for example,ditransitive verbs,asshown
in (3.9), aswell asverbsof behavior, movement,andsituation,asshown in (3.10) - (3.12),may
lexically sub-categorizefor anADVP or PP([MG82]).
(3.9)He gavea carto Mary.
(3.10)He behavedawfully/inan unexpectedway.
(3.11)He residesnearby/atmyhouse.
(3.12)He dresseswell/in slacks.
Moreover, asshown in (3.13)-(3.18),someADVP andPP(italics)canbeusedto modify phrasal
categories(bold-face)otherthanVP (3.13)andS (3.14), includingnounphrases(NP) (3.15),ad-
jective phrases(AP) (3.16),andotherPPs(3.17)andADVPs(3.18)([ODA93]).
(3.13)They workedquickly/in a frenzy.
(3.14)Probably/Inall likelihood, he will survive.
(3.15)Evendogsin captivityeatbones.
(3.16)Sheis completelycrazy abouthim.
(3.17)He sentflowersright/over to his enemies.
(3.18)At leastonce, hefell veryseriously in love.
80
![Page 98: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/98.jpg)
It is alsoimportantto notethatADVP andPPdon’t alwaysadjointo theelementbeingmodified.
Althougheveryadverbialmaynotbelicensedin everyposition,four positionswithin theclauseare
available to S- and VP-modifying ADVP and PP adverbials ([Ale97]), as shown in (3.19). As
[Ale97] discussesin moredetail,eachof thesepositionsmayalsohave aparentheticalcounterpart,
in which theadverbialis setoff by commas(or pauses)from therestof theclause.Again,however,
not all adverbialsarelicensedin every parentheticalposition([Ale97]). As discussedbelow andin
subsequentchapters,our dataset includesboth S-initial adverbialsthat arecomma-delimitedand
S-initial adverbialsthatarenotcomma-delimited,andwe do notdistinguishthemsemantically1.
(3.19)
S-initial: Of courseJohnwashurt.
S-medial(beforeauxiliary): Johndefinitelywashurt.
S-medial(afterauxiliary, beforemainverb): Johnwasprobablyhurt.
S-final(aftermainverb): Johnwashurtslightly.
3.2.2 Structure of PP and ADVP
Generallyin linguistics,thegrammaticalstructureof aphraseis representedwith aphrasestructure
rule2. Sucha rule is shown in (3.20),whereXP representsa phrasalcategory, andX representsthe
minimalelement,or head, aroundwhich therestof thephraseis built. Thearrow readsas“consists
of (in theordershown)”, andparenthesesindicateoptionalelements:SPECabbreviatesspecifier,
which is definedasan additionalphraseusedto make themeaningof theheadmoreprecise,and
COMP abbreviatescomplement, (or internal argument), which is definedasan additionalphrase
usedto supplyinformationthatis alreadyimpliedby themeaningof thehead([ODA93]).
(3.20)XP K (SPEC)X (COMP)
Prepositions(P) in English,which correspondthe headof a PP, area closedclassof lexical
items.Someexamplesof prepositionsareshown in (3.21).
(3.21)about,after, as,at,by, before,down, for, from, in, of, on,over, since,until,...
1See[FMPÑ 01] for furtherdiscussionof DLTAG’sextractionof S-internaladverbialdiscourseconnectives.2Seee.g.[ODA93] for furtherdetails
81
![Page 99: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/99.jpg)
Adverbs(ADV), which correspondtheheadof a ADVP, aregenerallyclassifiedinto two mor-
phologicaltypes:non-derived,or unsuffixed,andderived, includingsuffixedandcompoundforms
([Ale97]). In English,the-ly suffix predominates3; it canbeaffixedto mostadjectivesandto some
nouns(in the lattercasethe resultingform canoftenbeusedasbothanadverb andanadjective).
Thereareotheradverb suffixesaswell, including -wiseand-ally (the latter is usedon adjectives
endingin -ic). In addition,theprefix a-, which maybehistoricallyderivedfrom theprepositionon
([Suz97]), canform adjectivesandsomeadverbsfrom nouns.Examplesareshown in Table3.1.
Table3.1: Non-DerivedandDerivedAdverbs
Mor phological Type Examples
non-derived often,well, todaycompound-derived therefore,however, neverthelessadjective+ -ly briefly, fortunately, accusingly, swimmingly, *atomiclynoun+ -ly yearly, monthly, purposely, partly, kingly, *arrowlyadjective+ -wise likewise,otherwise-ic adjective+ -ally specifically, atomicallya- + noun ahead,apart
Perhapsbecausemany ADVP arecomposedof asingleadverb,thestructureof ADVP is notas
well studiedin linguisticsasPP([ODA93]). [CL93] consideradverbsa ‘minor’ lexical category,
wherethe four major lexical categoriesaredefinedby the featuresystemin (3.22). It is assumed
thatsubsidiaryfeatureswill distinguishadverbsandadjectives([Ale97]).
(3.22)[+N, -V] = noun [+N, +V] = adjective
[-N, +V] = verb [-N, -V] = preposition
Nevertheless,specifiersarecommonlyfoundin bothPPandADVP. Thesespecifiersaregener-
ally adverbs,asshown (italicized)in (3.23)-(3.25).In (3.25),theADVP specifieris obligatory.
(3.23)Themailmanis [ ÒcÒ almost/barely at thedoor].
(3.24)[ Ó$Ô Õ�Ò Very/Quitefrequently],I go to themovies.
(3.25)[ Ó$Ô Õ�Ò Longago],theearthwasformed.
3[Ale97] further notesthat in Greek-a and-ospredominate,in German-weisepredominates,in French-mentpre-dominates,andin Italian -mentepredominates.
82
![Page 100: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/100.jpg)
Frequently, prepositionstake a complement.Nounphrase(NP) complementsarecommon,as
italicizedin (3.26). PPandS complements(thelattercreatesa subordinatingconjunction)arealso
found,shown in (3.27)-(3.28),but in somecontexts a prepositionmaytake no complement,shown
in (3.29).A few adverbsalsotake complements,asshown in (3.30)([Ale97]).
(3.26)Mary hikes[ ÒcÒ in theGreenMountains].
(3.27)Thekidsare[ ÒcÒ down in thecellar].
(3.28)Herparentsarrived[ ÒcÒ aftersheleft].
(3.29)Herparentscame[ ÒcÒ over G ].
(3.30)Johnsucceeded[ Ó$Ô Õ�Ò independentlyfromour efforts].
While phrasestructurerulesrepresenttheinternalcompositionof anXP, tree-basedgrammars,
suchas[JVS99, Gro99], alsorepresentanXP’sexternalarguments,e.g.thephrasesto whichanXP
canadjoin,alongwith thestructurethatresults.XTAG treesfor anS-adjoiningPPwith aninternal
NPargumentandanS-adjoiningADVP with no internalargumentareshown respectively in Figure
3.1,where( Ì ) indicatesadjunction.
S� � ����PPÖ Ö××
P
As
NP
a result
SØ S� � ����ADVP
ADV
Consequently
SØFigure3.1: S-AdjoiningPPandADVP
3.2.3 Data Collection
Differencesbetweendiscourseadverbialsandclausaladverbialscannotbe attributedto their syn-
tacticstructure;asshown in Figure3.2,bothcanadjointo anSnode,andtheresultis anS.
Nevertheless,we canusetheir commonsyntaxto extract thedatafor study. Becausethesetof
adverbialsinfinite, it is not possibleto studythemall; thegoalof this datacollectionwasto gather
a largeandrepresentative setof thedifferentADVP andPPadverbialsthatwill commonlyappear
83
![Page 101: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/101.jpg)
in any Englishcorpora,with theexpectationthattheanalysiscanbeextrapolatedto novel tokens.
S� � � � ������PPÖ Ö××
P
As
NP
a result
SÍ Í ÍÎÎÎNP
people
VP
areself-centered
S� � � �����PPÙ ÙÚÚ
P
In
NP
spring
S� � ����NP
thelilacs
VP
bloom
Figure3.2: S-AdjoinedDiscourseandClausalAdverbials
Thedatastudiedin this thesisconsistsof the(correctlyannotated)S-initial, S-adjoinedADVP
andPPthat appearat leastoncein the PennTreebankI versionsof the parsedWSJandBrown
corpora[PT]. Thesecorporawerechosenbecausethey representa wide varietyof texts, including
news articles,essays,fiction, etc. In thePennTreebankI POS-taggingandbracketing system,S-
adjoinedADVP andPParebracketedassiblingsof theS they modify. In Figure3.3, for example,
thenis thetargetedADVP, andin fact is thetargetedPP.
Figure3.3: S-AdjoinedADVP andPPAdverbialsin PennTreebankI
Althoughasdiscussedabove,mostadverbialscanbefoundin avarietyof positions,S-adjoined
ADVP andPPwerechosenfor studyundertheassumptionthatthis is the“default” syntacticposi-
tion for mostadverbialdiscourseconnectivesandthat themajority of adverbial cuephrasesfound
84
![Page 102: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/102.jpg)
in otherpositionswill alsobe found S-adjoined4. The positionalvariability of adverbialsmeans
however that thecountsof extractedS-adjoinedadverbialsdoesnot reflectthecountsof thesead-
verbialsappearingin otherpositions.Moreover, becausetheunderlyingpositionof left-dislocated
adverbialsis not representedin PennTreebankI parses,thecountsalsoincludesomeleft-dislocated
nonS-modifiers.
The datawascollectedusing tgrep5, which is the UNIX commandgrep modifiedfor useon
syntacticparses.With tgrep,theuserspecifiesapatternusingnodenamesandrelationshipsbetween
nodes. The patternis thenmatchedagainsta corpusof syntacticparsesand thoseparseswhich
matchareextracted.Thepatternsusedto extractbothADVP andPPareshown in thefirst column
(topandbottomsections)of Table3.2; they areidenticalexceptfor theextractedelement.
Table3.2: tgrep Resultsfor S-AdjoinedADVP andPPin WSJandBrown Corpora
TGREP Pattern WSJ Tokens Brown Tokens
TOP Û (S Û (ADVP $. S)) 71 1604TOP Û (S Û (ADVP $. (/ Ü , / $. S))) 460 1388TOP Û (S Û (ADVP $. (/ Ü “/ $. S))) 0 1TOP Û (S Û (ADVP $. (/ Ü , / $. (/ Ü “/ $. S)))) 2 2TotalADVP Tokens 533 2995
TGREP Pattern WSJ Tokens Brown Tokens
TOP Û (S Û (PP$. S)) 372 1801TOP Û (S Û (PP$. (/ Ü , / $. S))) 4970 3135TOP Û (S Û (PP$. (/ Ü “/ $. S))) 0 1TOP Û (S Û (PP$. (/ Ü , / $. (/ Ü “/ $. S)))) 6 10TotalPPTokens 5348 4947
TherelevantrelationshipsbetweennodesareA Û B, meaningA immediatelydominatesB, and
A $. B, meaningA andB aresiblingsandA immediatelyprecedesB. TheTOPnoderestrictsthe
searchto mainclauses.Regularexpressionsareindicatedby surroundingthenodenamein slashes
(/). The caret(Ü ) anchorsthe regular expressionat the beginning of a word. Regular expressions
wereusedto extractcaseswherepunctuationintervenedbetweentheadverbialandthesisterS.
4Adverbialcuephrasesin otherpositionsmayserve information-structuringpurposes[FMPÑ 01]. Positionalvariationwill bediscussedfurtherbelow.
5See[PT] for documentationof tgrep, thePennTreebankI systemof POS-taggingandbracketing,andtheWSJandBrown corpora.
85
![Page 103: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/103.jpg)
The secondandthird columnsin Table3.2 shows the countsof adverbialsretrieved by each
patternin theWSJandBrown corpora.As shown, a quotationmarkrarely intervenedbetweenan
adverbialandtheir siblingS,but acommafrequentlyintervened.
Total countsof S-adjoinedadverbialstokensareshown in the first columnof Table3.3. Perl
scriptswerewritten to obtaintotal countsof eachadverbial typethatoccurredoverall, asshown in
thesecondcolumnof Table3.3.
Table3.3: TotalS-AdjoinedAdverbialsin WSJandBrown Corpora
Adverbial Category Total Tokens Total Types
S-adjoinedADVP 3528 849S-adjoinedPP 10295 7424S-adjoinedADVP andPP 13823 8273
Becauseit was taggedby humanannotators,however, the PennTreebankI-taggedWSJand
Brown corporacontainerrors. For thepurposesof this thesis,themoresignificanttypesof errors
werethefollowing6:H Incorrecttagging. For example,numerousADVP areincorrectlytaggedasPPandviceversa.H Incompletebracketing. For example,numerousADVP andPPareincorrectlytaggedasRB
(adverb)andIN (preposition),ratherthanasfull phrasalcategories.H Incorrect bracketing. For example,numerousADVP andPParebracketedasimmediately
dominatingtheadjacentS (insteadof their correctsibling relationship).
Incorrecttaggingerrorswerecorrectedby hand.While in principleit wouldhavebeenpossible
to incorporateincompleteandincorrectbracketingerrorsinto thetgrepextraction,doingsowould
have introduceda large amountof extraneousmaterial. As the goal of the datacollectionwasto
obtaina largeandrepresentative set,sucherrorswerenot incorporated.
6JuliaHockenmaier(personalcommunication)hascorrectedmany annotationerrorsin PennTreebankfor thepurposeof building aCCGgrammar([Ste96]);however dueto thepropertiesof CCGit wasnotnecessaryfor herto correcterrorsin theannotationof S-adjuncts.
86
![Page 104: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/104.jpg)
3.2.4 Summary
In thissectionwehaveoverviewedthestructureandfunctionof adverbials,andexplainedtheuseof
thesepropertiesto extractadatasetof ADVP andPPS-modifiersfor studyin subsequentsections.
3.3 Adverbial Modification Types
With theexceptionof the lexical semanticsproposedin [Kno96] thatwasdiscussedin Chapter2,
thesemanticsof mostdiscourseadverbialshasnotbeenwell studied.Mostpost-generative investi-
gationsof adverbials(c.f. [Ver97, Jac90, Gaw86,Ern84, Jac72]), treatsyntacticandsemanticissues
thatariseat theclauselevel, someof whichwill bediscussedbelow; whendiscourseadverbialsare
mentionedat all, they arecalledconjunctiveadverbialsor discourseconnectivesandarespecified
asthedomainof discourseresearch.
Nevertheless,we can usetheseclause-level investigationsas a guide when investigatingthe
semanticmechanismsthat causecertainadverbialsto function asdiscourseconnectives, because
all adverbialscanbe classifiedalongtwo semanticdimensions:(1) the type of modificationthey
perform; and (2) the semanticobject(s)they apply to. In this section,we investigatehow prior
analysesof modificationtypecanbeextendedto includediscourseadverbials.
3.3.1 Clause-Level Analysesof Modification Type
Becausethesetof adverbialsis so large,adverbialsareoftenclassifiedin theliteraturein termsof
thetypeof modificationthey perform.[Ale97] summarizesavarietyof modificationtypesthathave
beenproposedin the literature,asshown in Table3.4 with a correspondingexampleshown in the
secondcolumn7. Thoughthis classificationhasbeenappliedonly to ADVP, it canbeappliedto PP
aswell, asshown in thethird columnof thetable.
Modificationtypesvaryasto whetherthey areattributedto Sor VP modification.For example,
thefirst setshown in Table3.4 is generallyattributedto S-modification,while thethird setis gen-
erally attributedto VP modification;thesecondsethave beenvariouslyanalyzedasbothS andVP
7Negation’s adverbialpropertiesarevariouslytreated(c.f. [Ale97]) andarenotdiscussedin this thesis.
87
![Page 105: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/105.jpg)
modification(see[Ale97] for discussion).
Table3.4: [Ale97]’sModificationTypes
Modification Type ExampleADVP Example PP
Conjunctive consequently asaconsequenceEvaluative unfortunately to my disfortuneSpeechAct/Speaker-Oriented frankly to speakfranklySubject-Oriented courageously in acourageouswayModal probably in all likelihoodDomain legally in legal terms
Time today on thisdayFrequency frequently at mosttimesLocation here at thisplace
Manner correctly in acorrectwayCompletion/Resultative completely in acompletefashionDegree/Aspectual/Quantificational very/always to a largeextent/atall times
Modification typesalsovary somewhat dependingon the researcher. For example,Table3.5
shows [Ern84]’s classificationof themodificationtypesof S-modifiers.Again, thoughErnststud-
ies only ADVP, thesetypescanbe appliedto PP, as shown in the third column of the table. A
comparisonof theS-modificationtypesin two tablesrevealsthatwhile somedifferences,suchas
“modal” versus“epistemic”, are nominal, othersare categorical; Ernst, for example,subdivides
“subject-oriented”into two classes,“agent-oriented”and“mental-attitude”.
[KP02] definea yet anothersetof modificationtypesfor both S andVP modification,shown
in Table3.6alongwith ADVP andPPexamples;not all ADVP have a clearexample,however, as
indicatedby “?” in thetable.They usethis setto annotateall of theadverbialsthatappearin Penn
Treebank.This annotationis partof a largerprojectinvolving theadditionof semanticinformation
to parsedcorpora. As the primary focus of this project concernsthe similarity in the semantic
rolesplayedby verbalarguments,not adjuncts,acrossa variety of syntacticstructures,the setof
modificationtypesthey defineis understandablymoregeneral.For example,astheADVP andPP
examplesindicate,“temporal” is usedto labelboth“time” and“frequency” adverbials,and“other”
representsa remainderclass,e.g. for thoseadverbialswhosesemanticinterpretationdoesnot fall
88
![Page 106: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/106.jpg)
into any of theothertypes.
Table3.5: [Ern84]’sModificationTypes
Modification Type ExampleADVP ExamplePP
Conjunctive therefore asa resultEvaluative surprisingly to my surprisePragmatic frankly to speakfranklyAgent-Oriented wisely in awisewayMentalAttitude willingly in awilling wayEpistemic probably in all likelihoodDomain linguistically in linguistic terms
Table3.6: [KP02]’s ModificationTypes
Modification Type ExampleADVP Example PP
Temporal usually in themorningLocative here at thebarnDirectional back backto workManner quickly in ahurriedfashionPurpose ? in orderto getaheadDiscourse however in additionCause therefore becauseof thisOther probably exceptfor July4
Building on [Gaw86], [Ver97] takesanevenmoregeneralview of modificationtypes,although
heranalysisincorporates,to someextent,onthemorespecificmodificationtypesalreadydiscussed.
Following [Kas93, PS87],shedistinguishesonly threedifferenttypesof modifiers,basedontheway
in whichthey incorporatethesemanticcontentof themodifiedelement.Althoughthesedistinctions
coverbothADVP andPPadverbials,it is notclearwhetherall S-modifiershavebeenconsidered;the
focusof heranalysisis mainly on semanticdifferencesbetweenverbaladjunctsandcomplements.
In hercategorization,restrictiveadjunctsspecifythevalueof an index associatedwith a semantic
objectthatwaspreviously under-specified,suchasthetime or locationof anevent,asexemplified
by thetwo italicizedtemporalandlocative adverbialphrasesin (3.31a).
(3.31a) Johnjoggedyesterdayin thepark.
89
![Page 107: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/107.jpg)
In contrast,operator adjunctspredicateon thesemanticobjectthey modify andtherebybuild a
morecomplex semanticrepresentationof theobject,asexemplifiedin (3.32a)by thepredicationof
aneventby thetwo italicizeddurative andfrequentive adverbialphrases.
(3.32a) Johnjoggedtwicea dayfor twentyyears.
The third classof modifiersshecalls thematicadjuncts. Thesearestatedto be a group that
doesnot fit into eitherof the other two typesandaredescribedasadjunctswhich add thematic
informationaboutthe semanticobject,suchasthe causeof the event, or the meansby which the
eventoccurs,asexemplifiedby thetwo italicizedadverbialphrasesin (3.33).
(3.33a) Johnopenedhis doorwith a credit card becauseof therobbery.
Thepurposeof thesedistinctionsis to explain often-observed orderingrestrictionson different
adjuncts.In termsof thiscategorization,therelativeorderingof restrictiveadjunctsdoesnotusually
changethe interpretationof a sentence,asa comparisonof (3.31b) with (3.31a) shows. Because
restrictive adjunctssimply specify(or restrict) indicesof events,the orderin which theseindices
arespecifiedis irrelevant.
(3.31b) Johnjoggedin theparkyesterday.
Changingtheorderingof operatoradjunctscanchangetheinterpretationhowever, asacompar-
isonof (3.32b) with (3.32a) shows. Thefirst operatoradjunctassertsthedurationof the jogging
event,andthesecondoperatoradjunctassertsthefrequency of thejoggingeventwith its specified
duration. (3.32b) is in fact ungrammaticalbecauseit is temporallyimpossibleto repeatan event
thatlastsfor twentyyearstwice aday.
(3.32b) *Johnjoggedfor twentyyears twicea day.
Althoughnot discussedin [Ver97], thematicadjunctscanalsodisplayanorderingpreference;
(3.33b) seemsharderto processthan(3.33a).
(3.33b) ?Johnopenedhis doorbecauseof therobberywith a credit card.
In Section3.4we discussotheranalysesof relative orderingrestrictionsobservedin adjuncts.
90
![Page 108: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/108.jpg)
3.3.2 Problemswith CategoricalApproaches
As the varioussetsof modificationtypesindicate,it canbe difficult to achieve agreementon the
propernumberandtype of modificationsthat adverbialsperform. Dependinguponwhich setof
modificationtypesis selected,thereareadditionaldifficultiesaswell.
On theonehand,at a finer grainof analysis,suchasthatemployed in [Ale97] or [Ern84], it is
oftendifficult to decideinto which particularmodificationtypea givenadverbial shouldbeclassi-
fied. For example,thoughuseof theadverbquickly suchasis shown in (3.34)is oftenclassifiedas
conveying “manner”modification,at thesametimeit alsoconveys temporalinformation.Similarly,
thoughuseof adverbslike generally andhistorically] suchasshown in (3.35)areoften classified
asconveying “frequency” modification,they canalsobeviewedasconveying “domain” modifica-
tion, aswell asan expectationaboutprobability, akin to “epistemic” adverbs. And a greatmany
modifiersof a giventypecansimultaneouslybeviewedas“evaluative”, particularlythosethatare
“epistemic”(e.g.probably) and“agent-oriented”(e.g.wisely).
(3.34)Johnranquickly to thestore.
(3.35)Generally/Historically, Johnarrivesatwork on time.
Moreover, many adverbialshave different “readings”,eachof which may be classifiedinto a
differentmodificationtype. For example,briefly canbe classifiedasconveying a “manner” (and
“temporal”) modificationin (3.36a),but in (3.36b) it canbeclassifiedasconveying a “speech-act
oriented”(and“temporal”)modification.And many adverbsthatcanbeclassifiedas“manner”in a
sentencesuchas(3.37a)canbeclassifiedas“domain” in asentencesuchas(3.37b).
(3.36a) Johnsaidhewill stopby briefly.
(3.36b) Briefly, Johnsaidhewouldstopby.
(3.37a) Johnis growing emotionally.
(3.37b) Emotionally, Johnis growing.
Casessuchasclearly andobviouslycombinetheseambiguities.In additionto having multiple
“readings”which canbeclassifiedasconveying eithera “manner”or “evaluative” (and“spatial”)
modification,asshown respectively in (3.38a)-(3.38b) (examplesfrom [Ern84]), they simultane-
91
![Page 109: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/109.jpg)
ously convey propertiesthat areepistemic,in that the truth of the modifiedclauseis conveyed as
apparent.
(3.38a) Johnburpedclearly/obviously.
(3.38b) Clearly/Obviously, Johnburped.
And evenatsuchafinegrainof analysis,notall clausaladverbialsarerepresented.For example,
althoughthesetypeswerenot intendedto cover thewide varietyof PPadverbials(e.g. “exceptfor
this”) foundin ourcorpus(aswe will seein Section3.5), it is not clearwhereanADVP adverbials
suchas“regardlessof rightsandwrongs”would fall, which is alsofoundin our corpus(aswe will
seein Section3.6).
On theotherhand,even if a moregeneralsetof modificationtypes,suchasthatemployed in
[KP79] or [Ver97], is used,thesamedifficulty in decidingamongcategoriesfor a givenadverbial
canarise,in additionto theproblemthatpotentiallyvaluabledistinctionsarelost,anda“container”
classis necessaryto gatherremaindersthatdon’t fit in otherclasses.
3.3.3 Modification TypesasSemanticFeatures
On the surface, it might appearthat the modificationtypescould at leastbe usedto distinguish
discourseadverbials. After all, in Tables3.4 and3.5, discourseadverbialsareclassifiedas“con-
junctive”, and in Table3.6 they areclassifiedas“discourse”. But thesemodificationtypeshave
not beenableto distinguishclausalanddiscourseadverbials. For example,while clause-level re-
searcherstreat surprisingly, unfortunately, clearly as clausaladverbials, [Kno96] treatsthem as
discourseconnectives, as discussedin Chapter2. And in fact, all of the “conjunctive” or “dis-
course”adverbialscanbeclassifiedinto someothermodificationtype, for in contrastto theother
modificationtypes,whosepurposeis to isolatea particularpropertyconveyed by a setof adver-
bials,the“conjunctive” or “discourse”typeisolatesaparticularsyntacticstructureunderlyingaset
of adverbials.For example,discourseadverbialssuchasthen,first, finally, alreadycanbe(andare
in [KP79]) classifiedas“temporal”,becausethey convey temporalinformationabouttherelationof
theelementthey modify to thesurroundingdiscourse(or spatio-temporalcontext). Discoursead-
verbialssuchasasa result,consequentlycanbeclassifiedas“evaluative” if thecausalconnection
92
![Page 110: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/110.jpg)
betweentheelementthey modify andthesurroundingdiscourse(or spatio-temporalcontext) is not
commonknowledge8. Above we discussedproblemsof multiple typing andunclearclassification
asthey applyto clausaladverbials.Herewe seethattheseproblemsextendto discourseadverbials
aswell.
One solution to theseproblemslies in adoptinga non-categorical approachto modification
type. If modificationtypeswereviewedin termsof semanticfeatures,for example,thenadverbials
couldberepresentedassupplyingmultiple(compatible)features.Moreover, thesefeaturescouldbe
usedto representbothclausalanddiscourseadverbials. In suchterms,probablymight beused,as
exemplifiedin (3.39),to supplya degreeof likelihoodfeature9, while clearly andobviouslymight
beused,asexemplifiedin (3.40),to supplyevaluative,epistemic,andspatio-temporalfeatures.
(3.39)ProbablyJohnwoke upat 5 a.m.
(3.40)ObviouslyJohnwoke up at5 a.m.
Similarly, asexemplifiedin (3.41)-(3.42),both thenandon March 14, 1946might be usedto
supply temporalfeatures;only then suppliesthesefeaturesin termsof a relation with the prior
discourse.
(3.41)On March 14,1946, my fatherwasborn.
(3.42)Then, my fatherwasborn.
While suchanapproachrequiresfurtherstudy, suchfeaturescouldbesupplementedwith [Kno96]’s
featuresfor cuephrases,discussedin Chapter2. As statedabove, this approachwould overcome
theproblemsof multiple typingandunclearclassificationfoundin categoricalapproachesto modi-
ficationtypeby allowing adverbialsto supplyfeaturesfrom avarietyof modification“types”.
Whatmodificationfeaturescannotdistinguish,however, is thefact thatwhile thefeaturessup-
pliedby clausaladverbialsgenerallyapplyto entitiesand/orpropertieswithin themodifiedelement,
thefeaturessuppliedby discourseadverbialsapplyto themodifiedelementitself andthesurround-
ing discourseor context. Accountingfor thisdifferencerequiresdiscussionof thesemanticobjects
8[Kno96]’s“sourceof coherence”featuredistinguishesthisuseas“semantic”,asopposedto “pragmatic”,asdiscussedin Chapter2.
9[Ern84] makesa referenceto sucha feature,but hisanalysisappliesto categoricalmodificationtypes
93
![Page 111: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/111.jpg)
that theseadverbialssupplyfeaturesto. Considerationof theseobjectscanalsoclarify problems
with multiple readingsin bothclausalanddiscourseadverbials,therebydecreasingtheamountof
variationthatmodificationfeaturesarerequiredto cover. And it works theotherway too; under-
standingthemodificationfeaturesof adverbialscanclarify thepossiblesemanticobjectsthey can
apply to; togethertheseclassificationscanbeusedto build a formal semanticrepresentationof all
adverbials.It is thisdiscussionwhich is thesubjectof thenext few sections.
3.3.4 Summary
In thissection,wehaveshown thatthemodificationtypealoneis notsufficient to distinguishclausal
anddiscourseadverbials. We have suggestedthat someproblemsof multiple typing andunclear
classificationcanhoweverbeovercomeif modificationtypeis viewedin termsof semanticfeatures.
3.4 Adverbial SemanticAr guments
A numberof issuesconcerningthe semanticinterpretationof the externalsyntacticargumentof
adverbialshave beenaddressedat theclauselevel. In thissectionwe presenttheseissuesandshow
how they extend to the discourselevel. We show how the discoursedeixis researchintroduced
in Chapter2 exposesthe semanticobjectsthat adverbialsapply to anddistinguishesclausaland
discourseadverbialsin termsof thethenumberandtypeof thesesemanticobjects,therebylaying
thefoundationfor understandingthesemanticmechanismscausingthe“discourseconnectivity” of
discourseadverbials.
3.4.1 (Optional) Ar gumentsor Adjuncts?
As discussedin Section3.2,ADVP andPPcanfunctionbothasadjunctsandVP arguments;am-
biguity betweenthesefunctionshasmainly beenaddressedin relationto PP, but the analysesare
applicablealsoto ADVP.
A standardsyntactictest for VP argumentstructureis the “do so” test ([Ver97, KP79]). As
shown in (3.43a-b),wherebracketsindicatetheboundariesof theverbandits internalarguments
94
![Page 112: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/112.jpg)
anditalics indicatethereferentof “do so”, “do so” mustreplacetheentireVP, e.g. theverbandall
its arguments;thePPargumentcannotbeleft out.
(3.43a) *Mik e [gavea recommendationto Phyllis] andMary did soto Liz.
(3.43b) Mike [gavea recommendationto Phyllis] andMary did sotoo.
As shown in (3.43c-d), if thePPis anadjunct,however, it neednotbereplacedby the“do so”.
[SBDP00,Har99] explain thedifferenceasfollows: if thePPsuppliesanargument,thereis noway
to determinewhatsemanticfunction it serveswhenit modifies“do so”, because“do so” canrefer
to theinterpretationof modifiedandunmodifiedverbphrases10.
(3.43c) Mike [readthetextbook] in thebedroomandMary did soin theclassroom.
(3.43d) Mike [readthetextbook] in thebedroomandMary did sotoo.
[PS87]alsodiscussthe“iterability” test,which distinguishesVP adjunctsfrom argumentsbe-
causeonly adjunctscanbe“iterated”,asshown in (3.44).
(3.44a) JohnmetSusanin Chicagoin theHyatt hotel in thelobby.
(3.44b) *Johngaveabookto Debbieto Paul.
As [Ver97] pointsout,however, failing theiterability test,asin (3.44c), doesnotalwaysimply
argumentstatus;adjunctsarein generalnot iterableif their semanticcontribution is contradictory.
(3.44c) *JohnmetSusanin Chicagoin Boston.
[PS87]alsonotethat in English,argumentstendto precedeadjuncts,asshown in (3.45a). In
(3.45b), changingtheorderof thePPschangestheinterpretation;thebook,ratherthanthe“giving”
is readasbeinglocatedin thelibrary.
(3.45a) Johngave abookto Debbiein thelibrary.
(3.45b) Johngave abookin thelibrary to Debbie.
Furthermore,[PS87]note,many adjunctscauseextractionislands,asshown in (3.46a), while
unboundeddependency into argumentsis generallypossible,asshown in (3.46b). As [SBDP00]
10Suchtestsaren’t perfect,however; asBonnieWebbernotes(personalcommunication),(3.43a) soundsfine if wereplacegiveto with providefor: Mike provideda recommendationfor PhyllisandMary did sofor Liz.
95
![Page 113: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/113.jpg)
explain, in LTAG,extractionis modeledarelationamongelementarytreesin atreefamily thathave
essentiallythe samemeaninganddiffer only in syntax. In a treewherean elementis extracted,
its original positioncanbe locatedin a differenttreein thesamefamily, andits semanticscanbe
computed.Failedextractionindicatethat the modifier from which the elementis extractedis not
presentin any elementarytreein thetreefamily.
(3.46a) *Wheredid Johngive abookto Debbiein ?
(3.46a) Whomdid Johngive abookto in thelibrary?
Semantictestsfor distinguishingverbalargumentsandadjunctshave alsobeenproposed.As
[PS87]note,thesemanticcontribution of anargumentis dependentonthemeaningof thehead.For
example,in “Johntold astoryto Mary”, the“telling” musthavebotha “thing told” anda recipient;
“to Mary” fills the latter role. More formally, thesemanticcontribution of anargumentis entailed
by the sentencecontainingthe verb11. For example,the PPsin (3.47 a) areentailed( ¬ruv ) by the
sentencein (3.47b), thoughnot instantiated,but thePPsin (3.48a)arenotentailedby thesentence
in (3.48b) (examplesfrom [Ver97]). Theseentailmentpatternsindicatewhetheror not semantic
informationsuppliedby a PP(or ADVP) is directly relevantto themeaningof theverb([Ver97]).
(3.47a) Johncomplainedto Mary abouttheheat.
(3.47b) Johncomplained.¬ v hq�����Á¬ Johncomplainedto � about�(3.48a) Johnsangto Mary abouthis homeland.
(3.48b) Johnsang. ¬ruv h��Ŭ Johnsangto � , ¬ruv hq�Á¬ Johnsangabout�Another semantictest to distinguishverbal argumentsand adjunctsis the “presupposition”
test12. As definedin [Sae96], the presuppositiontest is appliedby comparingthe interpretation
of a sentencewith a modifier, asshown in (3.49a), to a correspondingsentencewithout themod-
ifier, wherethe informationsuppliedby themodifier is availablein theprior context, asshown in
(3.49b) (examplefrom [SBDP00]).If thetwo sentencescanhave thesameinterpretation,thenthe
modifierexpressesapresupposedsemanticargument.
11Theentailmentrelationin linguisticsis onein whichthetruthof onesentencenecessarilyimpliesthetruthof another([ODA93]).
12Generally, a presuppositionis an assumptionor belief implied by the useof a particularphrase([ODA93]), but acompleteaccountof presuppositionis still anopenquestion(c.f. Chapter5).
96
![Page 114: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/114.jpg)
(3.49a) Find thepowercable.Disconnectit from thepower adapter.
(3.49b) Thepowercableis attachedto thepower adapter. Disconnectit.
While noneof thesetestsarefoolproof ([SBDP00]),andtheargumentstructureof many verbs
is still undecided,clearcasesserve to show thatverbalsemanticargumentsaresometimessyntacti-
cally optional, althoughtheir semanticcontribution is still interpretedusingeithercontext or world
knowledge. Suchsyntacticallyoptionalarguments,alsocalled“hidden” or “implicit”, have been
widely discussedin linguistics,psycholinguistics,andcomputationallinguistics (c.f. [MTC95]).
Implicit argumentsaregenerallyclassifiedinto two types:definiteandindefinite. Definitehidden
argumentsareanaphoricto somesaliententity in the discourseor spatio-temporalcontext; their
interpretationis context-dependent. For example,in (3.50a)-(3.51a)optionalargumentsareinstan-
tiatedasPPswhoseanaphoriccomplementresolvesto thebold-facedelementin theprior clause.
(3.50a) Theduedatefor the grant haspassed.Mary didn’t apply for it.
(3.51a) Bill nearlyforgot aboutgoing to the bank. Johnremindedhim aboutit.
As shown in (3.50b) and(3.51b), theseargumentscanbeimplicit, but only if theinformation
necessaryto resolve themis suppliedby theprior context. (3.50c) and(3.51c) areinfelicituous,
becausethis informationis not retrievable.
(3.50b) Theduedatefor thegranthaspassed.Mary didn’t apply G .
(3.51b) Bill nearlyforgot aboutgoingthebank.Johnremindedhim G .
(3.50c) *Mary didn’t apply G .
(3.51c) *JohnremindedBill G .
Indefinitehiddenargumentsarenot anaphoricwith anything; their interpretationis indepen-
dentof context. [Mit82] discussesthe VP eat in detail, in constructionssuchas(3.52),which is
grammaticalwith or without theexplicit argumentevenwithout prior context. As shown in (3.53),
relationalNPs,suchasmother, winner, etc.,canalsocontainhiddenindefiniteNP arguments.
(3.52)Mary ate(something).
(3.53)Mary talkedto amother(of someone)today.
97
![Page 115: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/115.jpg)
Example(3.54)(from [MTC95]) shows that thedistinctionis not alwaysstrict. Whenimplicit,
thesyntacticallyoptionalargumentof theverbdonatecanbeanaphoricto informationin theprior
context, asin (3.54b), or canbeinterpretedasunspecifiedandthusindependentof any information
in theprior context, asin (3.54c).
(3.54a) TheUnitedWayaskedJohnfor acontribution. Johndonatedfivedollarsto them.
(3.54b) TheUnitedWayaskedJohnfor acontribution. Johndonatedfivedollars G .
(3.54c) Hardlyanyoneknows thatJohndonatesthousandsof dollarseachyear G .
3.4.2 External Ar gumentAttachment Ambiguity
EvenwhenanADVP or PPis identifiedasanadjunct,additionalambiguitiesmayexist. In partic-
ular, thepositionalvariability of ADVP andPPdiscussedin Section3.2 producesambiguityasto
thephrasalunit beingattachedstructurallyandmodifiedsemantically. A commonexampleof this
ambiguityis shown in (3.55),wherethePPwith a telescopeis ambiguousbetweenadjectival (NP
modifying)or adverbial(VP or Smodifying)attachment,yieldingambiguityasto whois in posses-
sionof thetelescope.Therearea numberof approachesto structuraldisambiguationof adjectival
versusadverbialPPattachment,includingprobabilisticones(c.f. [Bik00, CW00,McL01]).
(3.55)Johnsaw themanwith thetelescope.
A centralconcernfor many clause-level ADVP researchersis the ambiguitybetweenVP and
S modification;mostof theseresearchersseekto associateVP andS modificationwith particular
modificationtypes. (Schreiber1971),for exampletakesa “deepsyntactic”approach,arguing that
evaluative andmodaladverbsareunderlyinglyadjectivesthattake a sententialsubjectnominal.As
evidenceof thishecitesthesynonymy of thetwosentencesin (3.56a). Hearguesthatthissynonymy
distinguishesthemfrom VP modifiers,which, asshown in (3.56 b), cannotbe paraphrasedwith
sententialsubjectnominalsevenwhenthey areS-initial.
(3.56a) ThatJohnwasat faultwasobvious. K Obviously, Johnwasat fault.
(3.56b) *That Johnspoke to his friendwaswarm. K Warmly, Johnspoke to his friend.
98
![Page 116: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/116.jpg)
In [Swa88]’s terms13, the essenceof [Sch71]’s argumentis that a sentencecontainingan S-
modifyingadverbexpressesat leasttwo setsof propositionalcontent:theunmodifiedandthemod-
ified proposition. Swan take a differentview of the modifiedproposition,however, andincludes
subject-andspeaker-orientedadverbs.In Swan’s view, sentencesmodifiedby speaker-orientedad-
verbsarerepresentedasin (3.57). This representationindicatesthat, in additionto conveying the
unmodifiedproposition(S),speaker-orientedadverbsalsoconvey areducedpropositionconcerning
thespeaker (Speaker says(S)),which is modifiedby theADJ derivative of theadverb.
(3.57)(S), (ADJ(Speaker says(S)))e.g.frankly, honestly
Sentencesmodified by evaluative, modal and subject-orientedadverbsare representedas in
(3.58).This representationindicatesthat,in additionto conveying theunmodifiedpropositionitself
(S), theseadverbsalsoconvey areducedpropositionconcerningthespeaker in which thespeaker is
evaluatingasADJ theinformationin themodifiedproposition.
(3.58)(S), (Speaker says(ADJ(S)))e.g. fortunately, probably, courageously
[Gre69, AC74] take a “surfacesyntactic”approachto distinguishingVP andS modification,
arguingthatS-modifyingadverbscannotbethefocusof negationor interrogation.Thesetestsare
exemplifiedin Table3.7with theADVP italicized;asshown thesetestsalsoapplyto PPadverbials.
Table3.7: [Gre69]’sSyntacticTestsfor DistinguishingVP andS Modification
Syntactic Test ADVP Examples PP Examples
Adverbialis the He didn’t walk slowly. He didn’t walk at a slowrate.focusof negation *He didn’t walk probably. *He didn’t walk in all likelihood.
Adverbialis the Did hewalk slowly? Did hewalk at a slowrate?focusof interrogation *Did hewalk probably? *Did hewalk in all likelihood?
However, noneof theseapproachesaddressthe multiple readingsof adverbssuchasclearly,
obviously, strangelydiscussedabove; they passthetestsin Table3.7,asexamplifiedin (3.59a)-(3.59
b), becausethey displaymultiple “readings”;asVP-modifiers,they aresomevarietyof “manner”
13Swan’smaingoalis to provideacorpus-basedanalysisof English-ly Smodifyingadverbsashaving developedfromVP modifying intensifierandmanneradverbs,throughOld andMiddle English,by meansof syntactic/pragmaticshifts.
99
![Page 117: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/117.jpg)
adverbs,while asS-modifiersthey areoftenclassifiedas“evaluative”.
(3.59a) Johndidn’t burp clearly/obviously/strangely.
(3.59b) Did Johnburp clearly/obviously/strangely?
[Jac72] and[MG82] argue that suchcasesshouldbe treatedashomonyms, andgiven multi-
ple lexical entries. [Ern84] simplifiesthis analysisby giving adverbs,whenever possible,a single
semanticinterpretation,while leaving their syntacticargumentunderspecifiedin the lexical entry
whenmultiple interpretationsarepossible.For example,becausemodaladverbssuchasprobably
donotchangetheirmeaningnomattertheirpositionin theclause,asaclasstheirsyntacticargument
canbelexically specifiedin a singlelexical entryasS.But whenmultiple readingsarepossible,as
for obviouslyandstrangely, Ernsttreatsthesyntacticargumentaslexically underspecified,drawing
its syntacticargumentfrom theclosestdominatingnode14. Obviously, for example,alwaysconveys
that theargumentis obvious, but theargumentcanbea VP, yielding a mannerinterpretation,or an
S,yielding anevaluative interpretation.
Ernstalsoappliesthisargumentunderspecificationanalysisto adverbsthathavebeenpreviously
classifiedwith asinglemodificationtypebut thatalsodisplaysubtlydifferent“readings”.Examples
commonlyclassifiedas“agent-oriented”areshown in (3.60).
(3.60a) JohnapproachedtheDuchesstactlessly.
(3.60b) Tactlessly, JohnapproachedtheDuchess.
In Ernst’s analysis,tactlesslyin (3.60a)describesa judgmentaboutthe“approaching”,andthe
adverb takesa VP argument,while tactlesslyin (3.60b) describesa judgmentaboutthesituation
involving John’s actionof “approaching”,andtheadverbtakesanSargument.
In both cases,“John” is interpretedas “tactless”. However, Ernst arguesthat casessuchas
(3.61)-(3.62)show thatthis is only aninference.For example,wewouldnormallydraw from (3.60
a) the inferencethat Johnis tactless.But we canusethe S-modifierwith the opposingmeaning
(tactfully) in (3.61),alongwith theadditionalcontext providedby theVP adverbial(knowing...), to
blocktheinferredjudgmentthatJohnis tactless,while still assertingthatJohn’sapproachis tactless.
14In thenormalcase,that is. Many readerswill beableto getmultiple readingsin any position;arguablytheclosestdominatingnodecorrespondsto thefirst, or easiest,reading.
100
![Page 118: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/118.jpg)
(3.61)Tactfully, Johnapproachedthe Duchesstactlessly, knowing that apparentdisregardfor
authoritywashighly prizedin thisculture.
(3.62)Stupidly, Alice hadanweredthequestionswiselyandblown hercoverasaninmateof the
insaneasylum.
While S-readingscannotbefaked,asexemplifiedin (3.63),wherebothadverbsareS-modifiers
becausetheclosestdominatingnodeof bothis S,Ernstarguesthatthis lackof a felicituous“f aked-
reading”is accountedfor by thefactthattheS-modifiersassertopposingjudgmentsaboutthesame
semanticobject;theonly way to block oneof thejudgmentsaboutAlice is to explicitly claim that
thesurroundingcircumstanceswereabnormal,asin (3.64).
(3.63)*Stupidly, Alice wiselyhadanweredthequestions.
(3.64)Althoughit normallywouldhavebeenstupidfor Alice to blow hercoverasamime,Alice
wiselyhadansweredthequestionsbecauseshehadalreadynoticedthatherbackuphadarrived.
Ernst’s useof variationsin theexternalsemanticobjectinutitively feelscorrect. Investigating
theuseof adverbs(or PPs)with gradientmeanings(insteadof just opposingmeanings)would in-
dicateif morethantwo argumentattachmentsitesfor interpretingsemanticobjectswererequired;
adjectives, from which many adverbsarederived, aregenerallynon-gradient,however [WN98].
Nevertheless,Ernst’sanalysisis largelyunformalized,with respectto boththesyntacticandseman-
tic representationof adverbsandtheir arguments;moreover, it doesnot determinehow to decideif
asinglemodificationtype(suchas“temporal”) shouldbeviewedasSor VP.
[Ale97] basesthisdecisiononobservedorderingrestrictionsonadverbs,while alsoproviding an
analysisof thesyntacticrepresentationof adverbattachment.As discussedin Section3.3, [Ver97]
explainscertainorderingrestrictionsin termsof modificationtype; [Ale97], in contrast,explainsa
widervarietyof theserestrictionsin termsof bothmodificationtypeandunderlyingadjunctionsite.
[Ale97] notesthatstrict sequencingandscopehierarchiesattestedacrosslanguagesarecorrelated
with modificationtype. For example,in English,asexemplifiedusingmodaladverbsin (3.65a)-
(3.65b),S-modifyingadverbsmustappearhigherin thesyntactictreethanmanneradverbs,andas
shown in (3.66a)- (3.66b),evaluative adverbsmustappearhigherthanagent-orientedadverbs.
101
![Page 119: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/119.jpg)
(3.65a) ProbablyJohncleanedtheroomcarefully.
(3.65b) *Carefully Johnprobablycleanedtheroom.
(3.66a) Fortunately, Johncleverly climbedto thetopcarefully.
(3.66b) *Cleverly, Johnfortunatelyclimbedto thetopcarefully.
Workingwithin theMinimalist program,Alexiadouprovidesacross-linguisticsyntacticaccount
for suchrestrictionson ADVP accordingto their modificationtype. In his analysis,“manner”ad-
verbsarebase-generatedbelow theverb,andtheirappearancein otherpositionsinvolvesmovement
to aspecifierpositionof a functionalprojectionaslicensedby Minimalist principles.Otheradverbs
arebase-generatedasspecifiersof functionalprojectionsto the left of the verb. He distinguishes
a varietyof functionalprojections,distributesalongthem(astheir underlyingplaceof attachment)
ADVP that exemplify the variousmodificationtypes,andin eachcasedemonstratesthe rangeof
felicituoussurfacepositionsthatresultfrom movementof themodifiedphrasalcategories.
Of course,given how large the set of ADVP adverbials is, and the inability of modification
typesto fully categorizeall adverbs,it’s not clear if [Ale97] accountsfor all possiblesequences
andpositionsfor all ADVP adverbials. In particular, theapparentfreedomof comma-(or pause-)
delimitedadverbialssuchasshown in (3.65c) - (3.66c) is largelyunaccountedfor usingMinimalist
principles,althoughto be surethe felicitousnessof thesecasesmay vary to a greatextent on a
speaker-to-speaker basis,andthecasesthemselvesmaybemuchmorecommonin speechthanin
text, thusmakingthemanalyzableasself-corrections.
(3.65c) CarefullyJohn,probably, cleanedtheroom.
(3.66c) Cleverly, John,fortunately, climbedto thetopcarefully.
[Bie01] cites[McC88]’s treatmentof comma-delimitedmodifiersasS-adjuncts,but notesthat
this analysisallows infelicituoussentencessuchasshown in (3.67),whereotherthanMary should
beinterpretedasmodifyingeveryone, despiteits comma-delimitedS-medialposition.
(3.67)*What food,otherthanMary, repelseveryone?
In suchananalysis,the relationshipbetweeneveryoneandtheother thanMary phrasewould
have to be resolved anaphorically. [Bie01] proposesinsteada fully structuralanalysisin CCG
102
![Page 120: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/120.jpg)
[Ste00c] which usestype-raisingto cover the felicituouspositionsof alternativephrases.We will
discusshis semanticanalysisof thesephrasesin Section3.5.
3.4.3 SemanticRepresentationof External Ar gument
As discussedin Chapter2, muchof the linguisticsliteratureaddressesonly the propositioninter-
pretationof anS; thesemanticrepresentationof S is usuallya truth value: trueor false.Theabove
discussionindicatesthatS makesavailableotherinterpretationsaswell. In [Ver97, KP79], for ex-
ample,andacrosstheadverbialliteraturein general,referenceis madeto themodificationof events
andsituations. [Ern84] distinguishesaneven wider varietyof S interpretations,includingactions
(or events),situations,statesof affairs,andmentalstates. However, in mostcasesthisclassification
is describedrathervaguely;while theseinterpretationsmaybeusedto distinguishvariousproperties
of adverbials,thepropertiesdistinguishingtheseinterpretationsarenot well-defined.For example,
Table3.8providesthesemanticinterpretationsof someof Ernst’s modificationtypes15.
Table3.8: SemanticInterpretationsof [Ern84]’sModificationTypes
Example Modification Semantic Semantic DerivedADVP Type Inter pretation Object ( � ) ADJ
slowly Manner � is ADJ. action slowwisely Agent-Oriented agentjudgedADJ dueto � situation wiselegally Domain � relevant in ADJ domain situation legal
possibly Epistemic � is ADJ. situation possiblefortunately Evaluative � is ADJ. stateof affairs fortunate
angrily MentalAttitude ADJ manifestsagent� mentalstate angry
Thefirst columnof the tablecontainsanexampleadverb,andthesecondcolumncontainsthe
modificationtypeinto which it is classified.Thethird columncontainsthesemanticinterpretation
of themodification,anddefinesthe involvementof thesemanticinterpretation,� , that is equated
with theexternalsyntacticargument.Thespecificobjectequatedwith � for eachinterpretationis
shown in the fourth column. Note that Ernstmakesuseof the adjective (ADJ) derivative of the
ADVP; thefifth columncontainstheADJ derivative for eachadverb.
15Certainof Ernst’smodificationtypesaresubdividedwith respectto theseinterpretations.
103
![Page 121: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/121.jpg)
[Moo93], in contrast,providesa formal representationof thepossiblesemanticinterpretations
of ADVP adverbials’externalarguments.His formalizationis basedon thesamedataaddressedin
[Ern84], in particularthetwo differentinterpretationsexemplifiedin (3.68)-(3.69)thatareproduced
by a singleadverb locatedin differentpositions. Moore notesthat in (3.68),strangely intuitively
modifiestheeventof Johnsinging. In (3.69),however, thesingingeventmaybequiteordinary;it
is thefactthatJohnsangthatis strange.
(3.68)Johnsangstrangely.
(3.69)Strangely, Johnsang.
Following [Dav67], Moorearguesthateventsentences16 asserttheexistenceof anevent in the
domainof entities. It is this event, theseresearchersargue,thatstrangely modifiesin (3.68). This
is representedin predicatelogic asshown in (3.68’), where � representsa hiddenargumentto the
verb17 thatrangesoverevents,andstrangely is representedasadditionalpredicationof � . In words,
theformulaassertsthatthereexistsa singing-by-Johnevent,andthateventis strange.
(3.68’) h x(Sang(j,x)& Strange(x))
Moore further arguesthat true propositionsassertthe existenceof a situation (or fact) in the
domainof entities. In Moore’s view, it is this situationthat strangely modifiesin (3.69). This
is representedin predicatelogic asshown in (3.69’), where“Fact” denotesa relationbetweena
situationanda proposition,� is representedasa hiddenargumentto this relationthat rangesover
situations,andstrangely is representedasadditionalpredicationof � . In words,theformulaasserts
thereexistsasituation(fact)of therebeingasinging-by-Johnevent,andthatsituationis strange.
(3.69’) h y(Fact(y, h x(Sang(j,x)))& Strange(y))
3.4.4 SemanticAr gumentsasAbstract Objects
In essence,both Moore andErnstassociateadverbial VP attachmentwith event (or action) mod-
ification. While Moore associatesadverbial S attachmentwith situation (or fact) modification,a
16sentencesthatdescribeevents,in contrastto sentencescontainingthebeverb,e.g.Mary is kind.17See[Moo93, Dav67, BP83]for reasonswhy this argumentis associatedwith theverbandnot thesentence.
104
![Page 122: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/122.jpg)
situationis only oneof thepossiblesemanticinterpretationsthatErnstassociateswith adverbialS
attachment;healsomentionsthemodificationof statesof affairs andmentalstates.
In fact,thediscoursedeicticresearchdiscussedin Chapter2 providesevidencethatthepossible
semanticinterpretationsassociatedwith adverbial attachmentare more diversethan Moore and
even Ernstacknowledge. In Chapter2 we referredto thepossibleinterpretationsthatan S makes
available as abstract objects(AOs). As illustration, recall the variety of AO typesproposedby
[Ash93], shown againin Figure3.4. We demonstratedhow discoursedeixiscouldbeusedto refer
to theseobjects.
Figure3.4: [Ash93]’s Classificationof AbstractObjects
Also in Chapter2, [Ven67], [Web91], [DH95] and we ourselves observed that a variety of
additionalAOs, including descriptions,beliefs,speech acts, textual objects,andeven defeasible
rules anddiscourserelationscanbe the objectsof discoursedeixis reference.More generally, as
statedin Chapter2, thereareat leastasmany AOsasthereareabstractnouns.In many casesthey
canbereferredto via discoursedeixissimplyby insertingtheminto thesentence“That is a(n)...”.
Whetheror not theclassificationof AOs shown in Figure3.4 is complete,we arguethatAOs
provide an appropriateway of understandingadverbial semantics.We arguethat the rangeof se-
manticobjectsevokedwhenanadverbialmodifiesanScoincideswith therangeof semanticobjects
to whichadiscoursedeicticrefers.
As a preliminaryillustration,considerTable3.9. The third andfourth columncontainPPand
ADVP clausalanddiscourseadverbials.Thesecondcolumncontainscomparablediscoursedeictic
reference.For illustrative purposes,considerthesentencePeoplemademistakesastheonebeing
105
![Page 123: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/123.jpg)
referredto andmodified.Thefirst columnspecifiestheresultingAO interpretation.
Table3.9: AbstractObjectInterpretations
Abstract Object DiscourseDeictic PP Adverbial ADVP Adverbial
event/situation thathappenedafterwards afterthat, afterwards,fact that’s a fact in fact, really,proposition that’s true in truth, truly,description that’s agooddescription asadescription, descriptively,belief that’s my belief in my view, personally,speechact that’s to befrank in plainEnglish frankly,textual object repeatthat asa repetition again,
As the table shows, we can interpret the sentenceas a variety of AOs. If referredto by a
discoursedeictic,it is thepredicationonthediscoursedeicticthatdeterminestheAO interpretation.
For example,“happeningafterwards”,is apropertyof events,sothereferentof thediscoursedeictic
is interpretedasan event. If the sentenceitself is modified, it is the adverbial that performsthe
predication,therebydeterminingtheAOinterpretation.Forexample,“afterwards”,is alsoaproperty
of events,sothesentenceisagaininterpretedasanevent.Moregenerally, noticethatwecanin many
casescreatea PPadverbial for an AO simply by insertingit into thePP“As a(n) ...”. In Sections
3.5-3.6we will seeawide varietyof AOsinstantiatedin thisandotherS-modifyingadverbials.
Thoughour dataconsistsof S-modifying adverbials,we have not excludedeventsor distin-
guishedthemfrom situationsin theabove table,becausefor many S-modifyingadverbials,includ-
ing temporal,frequency andspatialadverbials,eventandsituationmodificationcannoteasilybe
distinguished.And if theseadverbialsmodify events, andeventsaremadeavailableby VP, then
eithera movementanalysisor a percolationanalysisis requiredto explain how theseadverbials
canmodify eventswhile adjoiningto S. Moreover, we will seein our datathat thepossibleinter-
pretationsof VP areasimportantfor distinguishingdiscourseandclausaladverbialsasthepossible
interpretationsof S,justasthey arefor distinguishingdiscoursedeicticreferencefrom NPreference
in demonstrative use.In Chapter6 wewill returnto theissueof semanticrepresentationof AOsand
adverbials,takinginto considerationboththeanalysesproposedin discoursedeixisresearchandin
adverbial research.Until then,we retainthedistinctionbetweenthesemanticorigin of eventsand
106
![Page 124: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/124.jpg)
situationsvia thephrase“AOsmadeavailableby S”.
For thepurposesof brevity in subsequentsections,we definea working terminologicaldistinc-
tion betweenconcreteobjectsandabstract objects. Theseobjectsaredistinguishedis asfollows:
concreteobjectsareentity interpretationsmadeavailable by (e.g. denotedby or inferablefrom
([Pri81])) NPs.Concreteobjectsareusually, but notalways,perceivableby thesenses[Ash93], and
includepeople, organizations,physicalobjects, etc.Abstractobjectsareentity interpretationsmade
availableby bothNPsandnon-NPconstituents,includingverbphrases,clauses,etc. As discussed
in Chapter2, abstractobjectsareusually, but not always,imperceptableto thesenses,andinclude
reasons,beliefs,trials, defenses,theories,rights, etc. In practicalapplication,the distinction is
moreof the “I will know it whenI seeit variety”, and it may not be categorical; demonstrating
it for every entity would requirean infinite corpus,which is impossible,or constructedexamples,
which areoftensuspect.Nevertheless,thetheoreticaldistinctionbetwenthesetwo typesof entites
clarifiesthe differencebetweenthe anaphoricityof discourseandclausaladverbials. However, it
doesnot accountfor AOsretrieved from thespatio-temporalcontext. Our corpusconsistsonly of
text, andthoughthereis somediscussionof this in thesubsequentsections,in our view, therole of
thespatio-temporalcontext is still anopenquestion.
3.4.5 Number of Abstract Objects
Clausaladverbials(e.g. in myview) anddiscourseadverbials(e.g. afterwards) arebothcontained
in Table3.9becausebothtake astheir externalsemanticargumentanabstractobjectinterpretation
madeavailableby S.Thus,atboththesyntacticandsemanticlevel, clausalanddiscourseadverbials
arenotdistinguishablein termsof theirexternalargument.
It is in termsof thenumberandinterpretationof their argumentsthatsignificantsemanticdif-
ferencesbetweenclauseanddiscourseadverbialsappear. Wearguethatthenumberof argumentsan
adverbial containsandthe interpretationof theseargumentsdeterminewhetheror not it functions
semanticallyasa discourseconnective andis therebyclassifiedasa clauseor discourseadverbial.
We claim thatdiscourseadverbialscontainat leastoneargumentthatdependsfor its interpretation
on somesalientAO containedin or derivable from the discoursecontext, which therebyrenders
107
![Page 125: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/125.jpg)
themuninterpretablewith respectto theirmatrixclausealone, evenafterresolutionof any concrete
objectarguments.In contrast,clausaladverbialscontainno suchargument;their interpretationis
context-independent afterresolutionof any argumentsto contextual concreteobjects18.
Discourseadverbialsare thusvery similar to discoursedeixis in that both requirean AO in-
terpretationfrom theprior discourseor spatio-temporalcontext for their interpretation.[WJSK03]
providestrongbehavioral evidencefor thisview. Forexample,justasin (2.50),repeatedfrom Chap-
ter 2, thediscoursedeictic takesasits referentthediscourserelationbetweenclauses,sodoesthe
PPadverbial,asoneexample, in (3.70)derive its prior argumentfrom theresultrelation(imparted
by so) betweenthetwo clauses.
(2.50)If a white persondrivesthis carit’s a “classic”. If I, a Mexican-American,drive it, it’s a
“low-rider”. Thathurtsmy pride. [DH95]
(3.70)Johnjustbroke his arm.So,asoneexample,hecan’t cycle to work now.
More generally, noticethatjustasadiscoursedeicticcanbereplacedby its explicit demonstra-
tive+AO counterpart,e.g. that text, that speech act, or that contrast in (2.50),in thesameway, we
canconstructan adverbial from a discoursedeictic or its explicit demontrastive+AO counterpart,
therebycreatinga discourseadverbial which explicitly relatestwo abstractobjects,e.g. for that
reason,in this case, after that, or asan exampleof theconsequencesof that in (3.70). Of course,
as(3.70)indicates,explicit demonstrative referenceis not theonly mechanismby which discourse
adverbialsarecreated.In thenext two sectionswe discussthesemechanismsin detail.
Beforebeginning our corpusanalysis,however, notethat theappropriatesemanticrepresenta-
tion of almostall the mechanismsdiscussedin Sections3.5-3.6is still an active line of research.
As such,thevariousresearchwe will discusshasemployeda varietyof formalizations(at various
levelsof complexity). As our goal in thesesectionsis to discernthesemanticmechanismsunder-
lying adverbial function, we will not be advocatinga particularformalization,but will presenta
varietyasrequiredto representtheparticularpropertieswe arefocusingon in eachof thesemantic
mechanismswe discuss.18As will be discussedin Chapter5, however, thereare other ways apart from their semanticsthat both typesof
adverbialcanevoke contextual AO interpretations.
108
![Page 126: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/126.jpg)
We alsoemphasizethat we have distinguishedclausalanddiscourseadverbialssemantically
basedonly onthenumberandinterpretationof theargumentsthey contain.It mayor maynotprove
useful in practicalapplicationto further distinguishclausalanddiscourseadverbialsaccordingto
the resolutionof their arguments.For, asnotedabove, andwe will seein the next two sections,
AOs aremadeavailable by both NPs and non-NPconstituents(as well as by language-external
context). Thus,if anAO is nominalizedin thediscourse,thedefinitesemanticargumentof a dis-
courseadverbialmayresolve to thatnominalization.A strongerdistinctionbetweendiscourseand
clausaladverbialswould assertthatan adverbial functionssemanticallyasa discourseconnective
if andonly if the interpretationof oneor moreof thesemanticargumentsit containsis dependent
on anAO thatis retrieved,or reifed([Web91]) from a non-NPconstituent.Sucha distinctionmight
be madeundertheassumption,for example,that NP-referenceis distinguishedfrom referenceto
non-NPconstitutentsin anaphoraresolutionalgorithms.Wewill discussthis issuein moredetailin
Chapter6.
3.4.6 Summary
In this section,we have presenteda numberof analysesproposedat the clauselevel to account
for the semanticinterpretationof adverbial modification. We have argued,andwill show in the
next section,that suchclause-level semantictools canbe extendedto accountfor commonalities
betweenclausalanddiscourseadverbials,while alsodistinguishingsemanticdifferencesbetween
them. In particular, we have arguedthat discoursedeictic researchprovidesa betterbasisfor the
classificationof thesemanticargumentsof adverbialsthanclause-level research,andhavepresented
our formaldefinitionsof thesemanticdistinctionbetweenclausaladverbials,whichdonot function
semanticallyasdiscourseconnectives,anddiscourseadverbials,whichdo functionsemanticallyas
discourseconnectives.Wehave definedthisdistinctionaccordingthenumberandinterpretationof
semanticargumentstheseadverbialsapplyto:
discourseadverbials: containat leastoneargumentthatdependsfor its interpretationonsome
salientAO containedin or derivable from the discoursecontext; their interpretationis context-
dependent.
109
![Page 127: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/127.jpg)
clausaladverbials: containno suchargument;their interpretationis context-independentafter
resolutionof any semanticargumentsto contextual concreteobjects.
We view thesedefinitions,andour discussionin thenext two sectionsof thesemanticmecha-
nismsthat motivatethem,asa startingpoint, providing a foundationthat is generalenoughto be
supplementedby avarietyof semanticformalisms.In Chapter4 wewill selectaworkingformalism
to show how thesemanticsdevelopedin thischaptercanbeincorporatedinto theDLTAG model.In
Chapter5, we will seeotherwaysanadverbialcancontribute to discoursecoherence.
3.5 S-Modifying PPAdverbials
As discussedin Section3.2, thesyntacticstructureof theS-modifyingPPadverbialsin our corpus
canbe respresentedwith the treein Figure3.5, whereP representstheprepositionhead,S repre-
sentstheexternalargument,Arg�6�� representstheinternalargument,andSPECrepresentsoptional
(specifiers)modifiersof thehead19.
SÍ Í ÍÎÎÎPPÍ Í ÍÝÝÎÎÎ
Spec P Arg�6�* S
Figure3.5: SyntacticStructureof S-Modifying PPAdverbials
Both syntacticallyandsemantically, therefore,all theprepositionalphrasesin our datasetare
binary predicates.As illustration, they canall be representedsemanticallyusinglambdacalculus
(c.f. [HK98]) as in (3.71), where“[[ ]]” representsan interpretationfunction, and preposition
representstherelationsuppliedby theprepositionto its arguments,� and � , wherewe resolve � to
the interpretationof the internalargument,and � to the interpretationof theexternalS argument.
For example,if m representstheinterpretationof theNPMary, thentheinterpretationof thePPfor
19Althoughasdiscussedin Seciton3.2,internalargumentsarenotalwaysfoundin PPs,only a few PPsin ourdatadidnot take an internalargument.Thesewereeithermisparsedsubordinatingconjunctionsor topicalizedverbconstituents(e.g.“on they cameout” Þ “they cameonout”.
110
![Page 128: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/128.jpg)
Mary canrepresentedasin (3.72),andif is(w,l) representsthe interpretationof theS work is life,
thenthefinal interpretationof theS-adjoinedclausaladverbialcanberepresentedasin (3.73).
(3.71)[[PP]] = ß x ß y.preposition(x, y)
(3.72)[[for Mary]] = ß y.for(m, y)
(3.73)[[For Mary, work is life]] = for(m, is(w,l))
Thus,thepredicate-argumentstructureof thePPadverbialdoesnotdistinguishclausalanddis-
courseadverbials.However, if we exchangeMary for that reason, weproducethediscourseadver-
bial for that reason. In orderto distinguishclausalanddiscoursePPadverbials,therefore,we must
investigatethesemanticmechanismsunderlyingthepredicateargumentstructureandinterpretation
of theinternalargumentsof thePPadverbialsin ourcorpus.
3.5.1 Proper Nouns,Possessives,and Pronouns
Approximatecountsin our corpusof typesandtokensof the internalargumentsdiscussedin this
sectionareshown in Table3.10.
Table3.10:ApproximateCountsof TokensandTypesof someInternalPParguments
# Tokens # Types Inter nal Ar gument
776 428 propernounsandyears307 273 singlenounsmodifiedby possessives192 68 pronouns
As shown, a numberof PPinternalargumentsin our datasetarepropernounsor years.Table
3.11providessomeexamplesalongwith their corpuscounts;themajority occurredonly once.
Table3.11:PPAdverbialswith ProperNounor YearInternalArgument
# PP Adverbial # PPAdverbial
2 after1832 8 in Tokyo2 by God 30 onFriday2 for Blanche 1 to Africa24 in August 1 until 1971
111
![Page 129: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/129.jpg)
Although propernounsandyearsmay be interpretedwith respectto the discourseor spatio-
temporalcontext, they do not refer to abstractobject interpretations;rather, they denotepeople,
places,animals,etc.,which we have calledconcreteobjects.Their semanticinterpretationcanbe
representedasexemplifiedin (3.74),wherebold-facerepresentsthedenotedconcreteobject.
(3.74)[[God]] = God
Someof theinternalargumentsin our corpusaresinglenounsmodifiedby a possessive proper
noun;Table3.12providessomeexamplesalongwith their counts.
Table3.12:PPAdverbialwith Possessive ProperNounInternalArgument
# PPAdverbial # PP Adverbial
1 despiteBerger’s report 1 to Ann’s consternation2 for God’s sake 1 to Welch’schagrin1 in Blanche’s defense 1 underYakov Segal’sdirection1 in Krutch’s view 1 with Herberet’s blessing1 in Plato’s judgment 1 within Erikson’s schema
As shown, we’ve providedcasesin which theheadnoundenotesanabstractobject.For exam-
ple, views, judgements,consternation,blessingareall abstractobjects.However, themodification
by possessive propernounsdoesnot make theseabstractobjectscontext-dependent;the seman-
tic representationof theseNPsis akin to therepresentationin (3.74).Of course,theseNPsmaybe
coindexedwith abstractobjectsin theprior discourse,asshown in (3.75),whereHerberet’sblessing
canbeinterpretedastheactionof Herberetraisinghishandandpraying.
(3.75) Herberetraisedhis handsandbeganto pray. Mike andMary knelt beforehim. They
lookedinto eachother’s eyesandsmiled.With Herberet’s blessing, they wouldbemarried.
A numberof the PP internal argumentsin our dataset arepronounsor areadverbsthat are
functioningaspronouns(e.g.now, then,here). Table3.13providessomeexamplesalongwith their
corpuscounts. As shown, many of thesepronounsareanimatepronouns,by which we meanthe
first andsecondpersonpronouns,andthird personpronounsthatreferto animateentities.Although
animatepronounsdo not refer to abstractobjectinterpretations,they areanaphoricor deictic,and
112
![Page 130: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/130.jpg)
mustbeinterpretedwith respectto NPspresentin (or inferablefrom [Pri81]) thediscourseor spatio-
temporalcontext. In [HK98], thesemanticinterpretationof apronounis representedasdenotingan
entity . via anindex + thatis mappedto . relative to anassignmentfunction j , wherej is determined
by acontext i . An exampleis shown in (3.76).
(3.76)[[you� ]] ��à = a3 (i), wherei might provide theassignmentfor + : j 3 =
}~~� 1 K Kim
2 K John
3 K Sandy
�&���Table3.13:PPAdverbialswith PronominalInternalArgument
# PPAdverbial # PPAdverbial # PP Adverbial
1 above me 4 for now 8 to me14 afterthat 2 from here 28 sincethen2 amongthem 2 from this 8 until recently5 beyondthat 4 in it 5 until then6 by now 4 in this 2 with that4 for me 1 like you 1 with them
Not all pronounsonly referto concreteobjects,however. As Table3.13shows, therearenumer-
ouspronominalinternalPPargumentsfoundin ourcorpusthatmaybediscoursedeicticandreferto
anabstractobjectinterpretation.Thesearecasesof demonstrative pronouns,inanimatethird person
pronounsit20, or adverbsfunctioningaspronouns.Demonstrative referenceto abstractobjectswas
discussedin Chapter2; we will discuss(discourse)deictic adverbsin Section3.6. The semantic
interpretationof thesepronominalscanberepresentedin thesameway asotherpronouns,e.g. as
denotingan entity . relative to a context-determinedassignmentfunction. The differenceis that
herethe context may determinethat + is assignedto an abstractobject interpretationof eitheran
NP or a non-NPconstituent.Thattheseinternalargumentscanreify abstractobjectsfrom non-NP
constituentsis shown in (3.77)-(3.78),whereboth that andthenrefer to theevent interpretationof
thefirst sentence.Notethepotentialfor ambiguity, however. In (3.79),thencanrefereitherto the
NP themorningor to theeventof wakingearly.
20Recallfrom Chapter2 however thatunlessthepredicationon it is sufficiently semantically-enhanced([Byr00]) (andthis is notprovidedby a preposition),anabstractobjectit refersto musthave alreadybeenreferredto with anNP.
113
![Page 131: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/131.jpg)
(3.77)I wentto themovies.After that, I ranahundrederrands.
(3.78)I wentto themovies.Sincethen, I’ve runahundrederrands.
(3.79)In themorning,I woke up early. Sincethen, I’ve runahundrederrands.
Therearealsoa numberof casesin our corpuswherethe internalargumentis a singlenoun
modifiedby apossessive pronoun.Someexamplesareshown in Table3.14.Again,we’veprovided
casesin which theinterpretationof themodifiednounsis anabstractobject.For example,natures,
opinions,knowledge areabstractobjects.Moreover, possessive pronounsareanaphoricor deictic,
but they referto concreteobjects.Therefore,likepossessive propernouns,theseNPsmay, but need
not,becoindexedwith abstractobjectsin theprior discourse.
Table3.14:PPAdverbialwith Possessive Pronoun
# PP Adverbial # PP Adverbial
1 by its nature 2 in my opinion1 beforehis departure 2 in my view1 despitehis yearning 1 to his surprise3 for his part 2 to my knowledge1 in ourcase 1 underhissupervision
3.5.2 Demonstrativeand Definite Determiners
Approximatecountsin our corpusof typesandtokensof the internalargumentsdiscussedin this
sectionareshown in Table3.15.
Table3.15:ApproximateCountsof TokensandTypesof someInternalPParguments
# Tokens # Types Inter nal Ar gument
468 266 singlenounsmodifiedby definitearticle310 180 singlenounsmodifiedby demonstrative determiner
Numerousinstancesof singlenounsmodifiedby thedefinitearticle (the) arefound asthe in-
ternalargumentof the PPadverbialsin our dataset. In somecases,thesenounsdenoteconcrete
objects;Table3.16providessomeexamplesalongwith their corpuscounts. In many cases,how-
114
![Page 132: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/132.jpg)
ever, thesenounsdenoteabstractobjects.Table3.17providessomeexamplesof definiteabstract
objectsalongwith their counts. Herewe seenumerousnovel examplesof abstractobjects,such
ascriticism, record, evidence. We alsoseethat somenounshave oneinterpretationasa concrete
object and anothermetaphoricalinterpretationas an AO, suchas board. We also seea deictic
noun,past(presentalsooccursin ourcorpus),which is alwaysinterpretedwith respectto eitherthe
spatio-temporalcontext or thediscoursetime.
Table3.16:PPAdverbialswith DefiniteConcreteObjectInternalArgument
# PPAdverbial # PP Adverbial
1 above thetongue 2 in thecity3 at thedoor 1 insidethecourtroom1 below thefort 1 nearthecoast1 beyondtheforest 1 sincethehurricane1 down theboulevard 1 towardthewest1 for theboy 1 within theindividual
Table3.17:PPAdverbialswith DefiniteAO InternalArgument
# PPAdverbial # PP Adverbial
1 acrosstheboard 1 for therecord2 afterthepayment 1 from theevidence2 afterthesplit 20 in theend6 alongtheway 14 in themeantime2 at theclose 18 in thepast11 at themoment 6 in theprocess17 at thetime 12 on thecontrary2 by theway 3 on thesurface1 despitethecriticism 4 on theway2 duringthetrial 7 undertheagreement4 for themoment 1 with theincrease
Semantically, definitenounsdenotea specificknown entity. However, definitenounsarenot
necessarilyanaphoricto somethingsalientin the prior discourseor spatio-temporalcontext. For
example,in (3.80),thetrial is inferablefrom thereifiedAO interpretationof thesuingevent.But in
(3.81),therecord simply refersto anabstractnotionof right andwrong.
115
![Page 133: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/133.jpg)
(3.80)JohnsuedMary for all shewasworth. During thetrial , hecriedprofusely.
(3.81)For therecord, graduatestudentsdon’t getpaidenough.
The definingsemanticfeatureof definitedescriptionsis that they areusedwhenonly oneen-
tity correspondsto their description([HK98]). Thus“the king of America” is infelicitousbecause
thereis no correspondingentity. [HK98] views this failureto referasa presuppositionfailure,and
representsdefinitedeterminersaspartial functionswhosedomaincontainsonly thosenounsthat
correspondto oneentity in thesetof individuals,andwhoserangecontainsthedenotationsof those
nouns.As noted,adefinitenounmayor maynotbeanaphoric,however, in thesensethatit recovers
anentity in theprior discourse.
Therearenumerousinstancesof singlenounsmodifiedby demonstrative determinersfound
asthe internalargumentof the PPadverbialsin our dataset. In somecases,thesenounsdenote
concreteobjects;Table3.18providessomeexamplesalongwith their counts.
Table3.18:PPAdverbialswith Demonstrative ConcreteObjectInternalArgument
# PPAdverbial # PPAdverbial
1 above thesejobs 2 in thisarticle2 at thatprice 2 in thisplay1 at theseoffices 2 of thatamount1 in thesefamilies 1 on thesegenerators1 in theseorganizations 1 to thesepeople
In thegreatmajority of cases,however, thesenounsdenoteabstractobjects.Becausemany of
thesenounsappearwith avarietyof demonstratives,we have conflatedthemin Table3.19in order
to presentawider variety. Herewe see“basic” AOssuchasevents,situations, andfacts. However,
we alsoseebackdrop andcircumstances, which canbesituations,studyandservice, which canbe
events,andbasisandreasonwhichcanbefacts.
Demonstrative NPs, like demonstrative pronouns,areanaphoricor deictic andmustbe inter-
pretedwith respectto the discourseor spatio-temporalcontext. They can either be represented
semanticallyakin to otheranaphoricreference,e.g.via anassignmentfunction,or they canberep-
resentedusingpartial functions,akin to definitedescriptions.And asis alsotruefor demonstrative
116
![Page 134: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/134.jpg)
pronouns,thecontext maydeterminethat they reify abstractobjectinterpretationsof VP or S. Ex-
amplesareshown in (3.82)-(3.83),wherethatserviceandthat reasonreferto theAO interpretation
of the first sentence.Again, however, the demonstrative NP’s referentmay be a previously men-
tionedabstractobjectNP, asin (3.84),or it maybeambiguous,asin (3.85),wherethat reasoncan
refer to thepreviously mentionedNP a reason, or it canrefer to theAO interpretationof thefirst
sentence.
(3.82)JohnhelpedMary washthecar. After that service, shepaidhim $40.
(3.83)Johncouldn’t sleep.For that reason, hegotoutof bed.
(3.84)Yesterdayyougavemeagoodreasonto move. For that reason, I thankyou.
(3.85)It wasn’t until yesterdaythatyou told meyour reasonfor leaving. For that reason, I am
madat you.
Table3.19:PPAdverbialswith Demonstrative AO InternalArguments
# PP Adverbial # PP Adverbial
1 afterthatservice 2 in thesecircumstances2 againstthat/thisbackdrop 5 in thisconnection1 alongtheselines 2 in thatevent21 at that/thispoint 1 in thatfunction2 at this stage 3 in this instance1 by thatlogic 4 in thismanner2 by that/thesemeasure(s) 8 in this/theserespect(s)1 by thisstandard 2 in thissense13 by that/thistime 12 in that/thisway1 despitethesechallenges 3 on this basis1 despitethesefacts 1 outsidethoselimits1 duringthisstudy 5 to that/thisend4 for thatmatter 2 underthisplan5 for that/thisreason 1 with thissituation25 in that/this/these/those case(s) 2 within that/thisframework
3.5.3 Indefinite Articles, Generic and Plural Nouns,and Optional Ar guments
Sofarwehaveexaminedhow explicit AO referencecreatesPPdiscourseadverbials.In thissection
weusesinglegeneric,pluralandindefinitesinglenounsto demonstrateothersemanticmechanisms
117
![Page 135: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/135.jpg)
at work in the internalargumentsof PPdiscourseadverbials.Approximatecorpuscountsof these
PPinternalargumentsareshown in Table3.20. This analysisalsoappliesto someof the internal
argumentsdiscussedabove; we have simply ignoredthisaspectuntil now.
Table3.20:ApproximateCountsof TokensandTypesof someInternalPParguments
# Tokens # Types Inter nal Ar gument
229 68 singlenounsmodifiedby indefinitearticles1020 233 singlegenericandpluralnouns
Therearenumerousinstancesof singlenounsmodifiedby indefinitearticlesfound asthe in-
ternalargumentof the PPadverbialsin our dataset. In somecases,thesenounsdenoteconcrete
objects;Table3.21providessomeexamplesalongwith their counts.
Table3.21:PPAdverbialwith IndefiniteConcreteObjectInternalArgument
# PPAdverbial # PPAdverbial
1 aftera roundup 1 in asaucepan1 asaboy 1 to astranger3 asagroup 1 underamicroscope1 for ananthropologist 1 with abellow
In many othercases,thesenounsdenoteabstractobjects.Table3.22providessomeexamples
alongwith their counts.Againwe seenumerousnovel AOs,includingrule, quirk, sense, etc.
Table3.22:PPAdverbialwith IndefiniteAO InternalArgument
# PP Adverbial # PP Adverbial
2 asa rule 1 in a fashion1 by a quirk 4 in asense18 in astatement 4 in away10 for amoment 1 on animpulse7 for awhile 1 to adegree
The semanticsof indefinitesis the subjectof much current research(c.f. [Roo95b, vdB96,
HK98, Hei82]). In [HK98] indefinitearticlesarerepresentedastotal functions,e.g. they placeno
118
![Page 136: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/136.jpg)
requirementson the nounsin their domain. More generally, theseindefinitenounscanbe repre-
sentedasunarypredicatesdenotinganunspecifiedentity; in predicatelogic this is representedasin
(3.86).
(3.86)[[an impulse]]= h x.impulse(x)
Theindefinitenessof thesenouns,whetherthey denoteconcreteobjectsor abstractobjects,does
not causethemto resolve or refer to entitiesin theprior discourse.This not to saythat certainof
theadverbialsin Table3.22arenotsometimestreatedasdiscourseconnectives;wearguehereonly
thattheir semanticinterpretationdoesnot requireanabstractobjectin theprior discourse.We will
returnto this issuein Chapter5.
Not all indefinitenounsareunarypredicates,however. Certainof the indefinitenounsin our
corpusare relational nouns,which take a syntacticallyoptional,or hidden, or implicit, argument
thatis anaphoricto somesaliententity in theprior discourseor spatio-temporalcontext. Examples
areshown alongin thefirst columnof Table3.23. In thesecondcolumntheseargumentsaremade
overt with ademonstrative.
Table3.23:PPAdverbialwith RelationalIndefiniteAO InternalArgument
# PP Adverbial Explicit Ar gument
2 asanalternative asanalternative to that2 asaconsequence asaconsequenceof that1 asa restatement asa restatementof that84 asa result asa resultof that1 for anexample for anexampleof that
We introducedsyntacticallyoptionalargumentsin Section3.4,usingexamplessuchas(3.50).
(3.50a) Theduedatefor the grant haspassed.Mary didn’t apply for it.
(3.50b) Theduedatefor thegranthaspassed.Mary didn’t apply G .
(3.50c) *Mary didn’t apply G .
Intuitively, whenoneapplies, they apply for something; in (3.50 a), this (for it) argumentis
overtandanaphoricto thegrant in theprior sentence,while in (3.50b), it is implicit but retrievable
from thecontext. In (3.50c) it is not syntacticallyoptionalbecausethecontext doesn’t supplyit.
119
![Page 137: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/137.jpg)
Similarly, if somethingis a result,consequence, or restatement, etc.,it is a result,consequence,or
restatementof somespecificsomething. Thus,we canmake this semanticargumentovert, as in
(3.87a),or leave it implicit, asin (3.87b), becauseit is retrievablefrom thecontext. However, the
discourseis infelicitousin (3.87c) becausethecontext doesn’t supplyit.
(3.87a) Theduedatefor thegranthaspassed.As a resultof that, Mary didn’t applyfor it.
(3.87b) Theduedatefor thegranthaspassed.As a result G , Mary didn’t applyfor it.
(3.87c) *As a result,Mary didn’t applyfor agrant.
Thesenounsarethusbinary predicates.Othernounsarealsoviewed asbinary predicates,as
discussedin Section3.4, including part (of something)andmother(of somebody). In predicate
logic, suchbinarypredicatenounscanberepresentedasshown in (3.88).
(3.88)[[result]] = h x h y[result(y,x)]
What predicatelogic cannotrepresent,however, is whetheror not this hiddenargumenthas
to be resolved in the prior discourse.As discussedin Section3.4, implicit argumentshave been
distinguishedinto two types: definiteandindefinite. As exemplifiedabove in (3.50), the implicit
argumentof apply is definite;it mustbeanaphoricto somethingin theprior context in orderto be
interpreted.In contrast,the implicit argumentof mother is indefinite; in Section3.4, (3.53) was
usedto exemplify indefinitehiddenarguments,which arenot necessarilyanaphoricwith anything;
their interpretationcanbeindependentof context.
(3.53)Today, Mary talkedto amother.
Althoughtheverbdonatein Section3.4(example3.54)indicatesthatsomeimplicit arguments
caneitherbe definiteor indefinitedependingon context, the implicit argumentsof the indefinite
nounsin Table3.23appearto alwaysbedefinite;at leastwhenfoundasthe internalargumentsof
thesePPadverbials,theseindefinitenounscannotbeinterpretedindependentlyof context andthus
the containingPPadverbialscannever be discourse-initial.Moreover, many of thesearguments,
implicit or explicit, appearto beabstractobjects.For example,a resultis a resultof acause, which
is anabstractobject.A restatementis a restatementof astatement, which is alsoanabstractobject.
Recallhoweverthediscussionof AOsin Chapter2,wherewenotedVendler’sobservationthatsome
120
![Page 138: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/138.jpg)
concreteobjectssuchasfire, blizzard canbeinterpretedascauses.
Of course,it canbedifficult to distinguishwhethera particularcasetakesa hiddenargument,
or merelyapotentialadjunct,especiallywhenthisargumentappearsto beindefinite.This is trueof
many of the indefinitenounsshown in Table3.22. For examplea sense, foundin thePPadverbial
in a sensein Table3.22, is likely interpretedasa senseof something. This somethingis clearly
indefinite,however, like thesomebodyargumentof mother, andsoit doesnot causethecontaining
PPadverbial to be uninterpretablediscourse-initially. More generally, we canusethe tests(e.g.
entailmentandpresupposition)discussedin Section3.4 that have beenusedto distinguishverbal
argumentsandadjuncts,but thesetestsarenot foolproof.
As onemight expect,thesamevariability in form we have seendisplayedby theinternalargu-
mentof ourPPadverbialscanbedisplayedby thesesyntacticallyoptionalarguments.For example,
in Table3.23,we madetheargumentexplicit with a demonstrative, but this argumentcanalsoap-
pearasa full nounphrase,andif thenounphraseis not anaphoric,asin (3.89),no prior context is
neededto interprettheadverbial.
(3.89)As aconsequenceof war, peopledie.
Furthermore,thesamevariability in resolutionwehaveseendisplayedby theinternalarguments
of our PPadverbialscanbe displayedby thesesyntacticallyoptionalarguments.For example,in
(3.90a), theinterpretationof thedemonstrative resolvesto theabstractobjectinterpretationof the
VP, e.g.giving him a book, but in (3.90b), theinterpretationof thedemonstrative is ambiguous;it
canresolve to givinghima bookor to theNP a book.
(3.90a) If Johnis bored,give him abook.As analternative to that,take him to thezoo.
(3.90b) If Johnis bored,give him abook.As analternative to that,give him amagazine.
Thereis a distinction,however, betweenthesebinarynounsthatwe have sofar ignored.While
thehiddenargumentsof result,consequence, restatementcanresolve to singleAO interpretations,
thehiddenargumentof examplemustresolve to a setof interpretations.This propertyof example
is notedin [WJSK03]. For example,in (3.91a), this argumentresolvesto thesetof consequences
of Johnbreakinghis arm,asis madeovert in (3.91b).
121
![Page 139: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/139.jpg)
(3.91a) Johnjustbroke his arm.So,for anexample,hecan’t cycle to work now.
(3.91b) Johnjust broke his arm. So, for anexampleof theconsequencesof breakinganarm,
hecan’t cycle to work now.
Thisanalysisreadilyextendsitself to genericandpluralnouns,whicharequitefrequentlyfound
in our corpusasinternalargumentsof PPadverbials.Again, thesenounsmaybeconcreteobjects;
Table3.24providessomeexamples,alongwith their counts.
Table3.24:PPAdverbialswith Genericor PluralConcreteObjectInternalArguments
# PP Adverbial # PPAdverbial
1 amongprofessionals 1 in academia2 asartists 1 like lemmings1 below decks 1 to libertarians2 for corporations 1 within institutions
Our corpusalsocontainsmany examplesof plural or genericnounswhich denoteabstractob-
jects;Table3.25providessomeexamplesalongwith their counts.
Table3.25:PPAdverbialswith Genericor PluralAO InternalArguments
# PP Adverbial # PP Adverbial
6 at times 1 in emergencies3 by law 1 in truth105 in fact 1 on occasion4 in practice 1 on reflection2 in reality 2 over time1 in theory 2 without question
Like indefinites,the semanticsof genericandplural nounsis the subjectof currentresearch
(c.f. [Roo95b, vdB96, HK98]). Generally, thesegenericnounscanbe representedeitherakin to
indefinites,e.g. asunarypredicatesdenotinganunspecifiedentity, or akin to plural nouns,which
canberepresentedasunarypredicatesdenotinganunspecifiedsetof entities,asshown in (3.92)21.
(3.92)[[professionals]]= e x.professional(x)
21Thequantifiersuggestsiteration,which is notalwaysthecase.
122
![Page 140: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/140.jpg)
Whetherthey denoteconcreteobjectsor abstractobjects,thegeneric-nessandplurality of these
nounsdoesnot causethemto retrieve entitiesin theprior discourse.Again,however, certainof the
adverbialsin Table3.22 (e.g. in fact, of course) arefrequentlyviewed asdiscourseconnectives;
asstatedabove, we arguehereonly that their semanticinterpretationdoesnot requirean abstract
objectin theprior discourse,andwill returnto this issuein Chapter5.
However, aswealsofoundfor indefinitenouns,certaingenericandpluralnounsarerelational,
andappearto take a syntacticallyoptional,or hidden, or implicit, argumentthat is anaphoricto
somesaliententity in theprior discourseor spatio-temporalcontext. Therearemany examplesof
suchgenericnounsfoundastheinternalargumentsof PPadverbialsin ourcorpus.Someexamples
areshown in Table3.26.
Table3.26:PPAdverbialswith RelationalGenericAO InternalArguments
# PP Adverbial # PP Adverbial
1 asevidence 3 in effect1 by analogy 3 in essence10 by comparison 1 in exchange28 by contrast 3 in part167 for example 6 in response70 for instance 8 in return204 in addition 5 in sum1 in comparison 117 of course2 in conclusion 3 on average1 in consequence 3 on balance16 in contrast 1 on reflection
Again, it canbe difficult to distinguishwhethera particularcasetakesa hiddenargument,or
merelya potentialadjunct.It appearsthatall of the(assumed)hiddenargumentsin Table3.26can
resolve to the AO interpretationof a VP or S in the prior discourse.For example,in (3.93), the
implicit (or explicit demonstrative) argumentresolvesnot to oneof theentitiesJohn,movies,Mary,
but to theactionof Johngoingto themovieswith Mary.
(3.93)Johnwentto themovieswith Mary. In exchange(for that),shegave him abackrub.
However, not all of theseargumentsareclearlydefinite. As in Section3.4,wherewe saw that
123
![Page 141: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/141.jpg)
thedefinitenessof theoptionalargumentof donatewasto someextentdependentoncontext, sodo
we seea similar dependency for on average andin essence. For while anaverage is anaverageof
(or over) something, andan essenceis an essenceof something, only in (3.94a) and(3.95a) are
these“somethings”anaphoricto anAO interpretationin theprior context. In (3.94b) and(3.95b)
these“somethings”areinterpretedindependentlyof context.
(3.94a) Wechoosetheactors,we build thesets,andwe keepthebooks.In essence, we run the
show. (shortenedWSJexample)
(3.94b) In essence,I amahappy person.
(3.95a) Mike washesthe dishes.Mary driesthemandputsthemaway. On average, they do
aboutthesameamountof work.
(3.95b) Onaverage,Johnis ahappy person.
Furthermore,aswe saw with indefinites,many of thesyntacticallyoptionalargumentsin Table
3.26 canresolve to a set, including the optionalargumentsof instance, part, sum,average, and
essence. Wewill discusssetsin greaterdetail in Section3.6andChapter5.
3.5.4 PP and ADJP Modifiers
Sofarwehaveonly seenactualcorpusexamplesof singlenouninternalarguments.Modifying these
internalargumentswith PPsandADJPscanalsocreatediscourseadverbials. Table3.27presents
approximatecountsin our corpuswherethe internalPPargumentis a singlenounmodifiedby a
singlePPor ADJ.
Table3.27:ApproximateCountsof TokensandTypesof someInternalArgumentModifiers
# Tokens # Types Modifier
1491 1400 singlenounwith PPmodifier1926 1143 singlenounwith ADJ modifier
Clearly, PPmodifiersof theinternalargumentsof PPadverbialscancreatediscourseadverbials
becausePPmodifiersthemselvescontainan internalargument,andit canbeanalyzedin thesame
way that we have alreadybeenanalyzingthe single noun internal argumentsof PP adverbials.
124
![Page 142: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/142.jpg)
As a particularlyrelevant example,in Tables(3.29)-(3.28),we provide corpuscasesin which the
syntacticallyoptionalsemanticargumentsof binarydefinite,indefinite,andpluralor genericnouns,
respectively, aremadesyntacticallyovert by aPP.
Table3.28:BinaryDefiniteInternalArgumentwith Overt Argument
# PP Adverbial
1 at thebeginningof thehippodrome1 at theendof theday1 at theinsistenceof Arturo Toscanini1 at theoutsetof his career1 in thecaseof academicpersonnel1 in themidstof it all1 in thecourseof this1 on thebasisof this carefulreading1 sincethestartof thedecade1 with theexceptionof satiresof circumstance
Table3.29:Binary IndefiniteInternalArgumentwith Overt Argument
# PP Adverbial
1 asanevocationof timepast1 asanexampleof this lastfacet1 asanillustrationof theprincipleof simplicity1 asanindicatorof thetight grainsupplysituationin theU.S.1 asanintroductionto Americanpolitics8 asamatterof fact1 asapartof overall efforts to reducespending1 asa resultof thatattitude1 in aseriesof fairy talesandfantasies
The NPswithin thesesyntacticallyoptionalPPsagaindisplaya variety of novel abstractob-
jects,conveyed in a varietyof forms. For example,in theabove two tableswe find demonstrative
pronouns(e.g. this in in thecourseof this), demonstrative nouns(e.g. that attitudein asa resultof
thatattitude), genericnouns(e.g.simplicity in theprincipleof simplicity in asan illustration of the
principle of simplicity), etc. As alreadynotedabove in constructedexamples,makingthesyntacti-
cally optionalargumentof arelationalnounovertmaymovetheburden(of classifyingtheadverbial
125
![Page 143: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/143.jpg)
containingit asa discourseor clausaladverbial) to theinterpretationof this overt argument.More
generally, regardlessof whetheror notaPPmodifieris asemanticargumentof thenounit modifies,
it introducesadditionalentitiesthatmayor maynot referto AOsin theprior discourse.
Table3.30:BinaryGenericor PluralInternalArgumentwith OvertArgument
# PPAdverbial
5 aspartof theagreement1 by meansof this socialcontrol1 in accordancewith legislationpassedat thelastsessionof Congress1 in additionto freemassages1 in anticipationof thatshift1 in caseof adeadlockbetweenprisonboardsandinmates1 in connectionwith thisconference1 in continuationof thesetheoreticalstudies1 in contrastto all this1 in exchangefor higherpricesupports1 in light of all this4 in point of fact1 in reactionto proposedcapital-gainslegislation1 in responseto this3 in spiteof this1 in termsof volume2 on topof all this
Adjectival modificationof aninternalargumentcanalsocauseit to beinterpretedwith respect
to discourseor spatio-temporalcontext. Thesimplestcasesin which to seethis arePPadverbials
whoseinternalargumentis modifiedby an adjective whoseinterpretationdependson the spatio-
temporalpropertiesof eitherthe discourseor the context. Someexamplesareshown Table3.31,
modifying anounthatcanbeinterpretedasanabstractobject.
Table3.31: InternalArgumentwith aSpatio-TemporalADJ
# PP Adverbial # PP Adverbial
3 undercurrentrules 1 for presentpurposes22 in recentyears 1 undermodernconditions
Therearemany otherdifferentclassesof adjectivesin our corpus;adjectivesareasvaried(and
126
![Page 144: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/144.jpg)
asdifficult to imposeclassificationon) asadverbs.Onemajorfunctionalclassfoundin our corpus
includesadjectives([MW]) thatcanfunctionasdeterminers,includingdistributives(all, both,either,
each, every...), cardinalnumbers(one, two...), otherquantifiers(few, some, any...), and“dif ference
words” ([gra]) or “alternative phrases”([Bie01]) (another, other, such, same).
Somedistributivescausetheir associatednounto beinterpretedwith respectto anentity in the
prior discourse.Whenthis associatednoun is an abstractobject, it is interpretedwith respectto
an AO in the prior discourse.Someexamplesof PPadverbialscontainingsuchdistributives and
anassociatedabstractobjectareshown in Table3.32. In general,nounsmodifiedby distributives
referto groupsor individualsin groupsfrom in theprior discoursecontext ([gra]). [HK98] usesof
partialfunctionto representthesedistributivessemantically, akin to thedefinitearticle,but wherea
specifiednumberor setof entitiesis denoted.
Table3.32: InternalArgumentwith ReferentialAdjective
# PP Adverbial # PP Adverbial
1 by bothstandards 7 in eachcase5 in bothcases 1 in eachinstance1 in bothrespects 5 in eithercase1 in bothconditions 1 in eitherevent
Otherdistributives, alongwith the cardinalsandquantifiersnotedabove, do not elicit an en-
tity in theprior context for their interpretation.Someexamplesfrom our corpusof PPadverbials
containingthesedeterminersandan associatedabstractobjectareshown in Table3.33. Because
theNP they produceis non-referential,[HK98] usestotal functionsto representthesedeterminers,
suchthatoneandsomeNP denoteanunspecifiedentityakin to indefinitenouns,andtheremainder
denotesetsof unspecifiedentities,akin to plural nouns.Nevertheless,certainof theadverbialsin
thesetableshave beentreatedasdiscourseadverbials,including in anyevent. We will investigate
possiblecausesof this in Chapter5.
Many of thesedeterminerscanfunctionasnounmodifiers;thefirst columnof Table3.34shows
NPscontainingthesemodifiersandadditionaldeterminers.Of course,thesemanticsof thedeter-
miner mustnot contradictthesemanticsof themodifier (e.g. “few onehand”),but mayeffect its
127
![Page 145: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/145.jpg)
referentialproperties,asin on theonehand, wherethemaycauseonehand to refer to a situation
(metaphorichand) in the prior context. Leaving the modifiedargumentimplicit asshown in the
secondandthird columnsmay alsoeffect the referentialpropertiesof theseadverbials;someand
onerequirethisargumentto beresolved.Wewill discussotheranalysesof after all in Chapter5.
Table3.33: InternalArgumentwith Non-ReferentialAdjective
# PP Adverbial # PP Adverbial # PP Adverbial
7 at onepoint 1 by all accounts 6 at any rate21 for onething 1 by all means 1 by any measure1 in onecase 4 in all cases 24 in any case1 in onesense 2 in all fairness 13 in any event2 in oneway 1 in all probability 1 in any instance1 in two cases 3 by someestimates 7 in mostcases1 on two occasions 2 for somereason 1 by mostaccounts1 for many reasons 5 for sometime 1 in severalinstances7 in many cases 4 in somecases 5 with few exceptions1 in many instances 4 to someextent 2 in certainrespects2 in many ways 1 in every period 1 undercertaincircumstances
Table3.34: InternalArgumentwith DeterminerandNon-ReferentialAdjective
# PP Adverbial # PP Adverbial # PP Adverbial
1 in a few instances 9 above all 1 to some1 in acertainsense 49 afterall 1 for thosefew7 for themostpart 3 in all 1 at themost8 on theonehand 2 in one 2 for one
Ordinalsandordinal-like adjectivesarealsofound in our corpus,with or without determiners,
asshown in Table3.35. As shown in the third column, their argumentcanbe implicit. We will
discussordinalsfurtherin Section3.6.
“Dif ferencewords”, or “alternative phrases”alsocausetheir associatednounto be interpreted
with respectto anentity in theprior discourse.Whenthis associatednounis anabstractobject,it
thuswill beinterpretedwith respectto anAO interpretationin theprior discourse.Someexamples
of PPadverbialscontainingalternative phrasesandanabstractobjectareshown in Table3.36.
Anotherandother invoke something“dif ferent,remaining,or additional”, thusthey arecalled
128
![Page 146: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/146.jpg)
Table3.35: InternalArgumentwith OrdinalAdjective
# PP Adverbial # PP Adverbial # PP Adverbial
1 in afirst step 1 on secondthought 17 at last6 for thefirst time 1 at lastreport 16 at first2 in thefirst instance 1 in thesecondplace 3 in thesecond
Table3.36: InternalArgumentwith Alternative Phrase
# PPAdverbial # PP Adverbial # PPAdverbial
1 in anotherapproach 20 amongotherthings 1 in suchcases1 in anothercase 24 in otherwords 2 in suchcircumstances1 in anotherrespect 2 on othermatters 2 in suchsituations1 in anothersense 1 amongotherissues 1 onsuchoccasions
“dif ferencewords”in [gra]; otherandsuch alsocreatewhatarecalledalternativephrasesin [Bie01].
As determiners,anotheris usedwith singular, andotherwith pluralnouns,but they alsofunctionas
modifiers;thefirst columnof Table3.37showsNPscontainingthesemodifiersandadditionaldeter-
miners.Thesecondcolumnpresentsanotheranaphoric“dif ference”adjective,same, thatrequiresa
determiner. Thethird columnshows thatthemodifiednouncansometimesbeimplicit.
Table3.37: InternalArgumentwith DeterminerandAlternative Phrase
# PP Adverbial # PP Adverbial # PP Adverbial
49 on theotherhand 71 at thesametime 1 for another1 in many otherinstances 2 in thesameway 2 on theother
[WJSK03, Bie01, Mod01] discussthesemanticinterpretationor resolutionof other, such, and
otheralternative phrasesin detail.They views theform otherX asa lexical anaphorwhichrefersto
theresultof excludinganentity or setof entitiesfrom a contextually relevantset,andpresupposes
that theexcludedentity or entitiesbelongto thatset. For example,manyother instancesrefersto
thesetof instancesthatresultfrom excludingone(or more)instancein thediscoursecontext from
129
![Page 147: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/147.jpg)
alargerpresupposedsetof instances.Theform anotherX (e.g.anotherX) canbetreatedsimilarly;
for example,anotherapproach refersto the approachthat result from excluding one (or more)
approachesin thediscoursecontext from a largerpresupposedsetof approaches.[Bie01] treatsthe
form such X asincluding, ratherthanexcluding, membersof a set. In his terms,for example,such
situationsrefersto thesetthat resultsfrom usingone(or more)situationsin thediscoursecontext
asan exampleof a presupposedsetof situationsthat alsoincludesthe setreferredto by the such
phrase. The form the sameX appearsto be a direct reference,akin to that X, althoughthereis
somesubtletyafoot in thata new entity canbeintroducedvia thedeterminer, albeit identicalin all
respectsto theoriginal.
[Bie01]’s analysisalso incorporatesthe non-anaphoriccounterparts(e.g. X’s other than/such
as/thesameas Y) of thesephrases.Thesecounterpartsdo not appearin our data,andsoundrel-
atively awkward as internalargumentsof PPs(e.g. in manyother instancesthan this). Bierner,
following [McC88], treatstheseoptionalPPphraseswhich instantiatetheexcludedor includedel-
ementasadjunctsratherthanarguments([Bie01], pg. 28),andusestheAI planningheuristic,“use
existingobjects”[Sac77] to resolve them.In bothBierner’sandour terms,theexcludedor included
anaphoricelementis representedasa hiddenargument. Its interpretationmay be partially deter-
minedby themodifiednoun(e.g. it’s an instancein otherinstances; however, theinterpretationof
casessuchason theother is wholly dependentoncontext, becausethemodifiednounis implicit.
Bierner’s analysisalsoextendsto otheradjectives encounteredin our corpus. Theseare the
comparative andsuperlative adjectives,which by definitionaredependentin an idiosyncraticway
onreferenceto at leastoneotherobjectthatmaybefoundin or inferablefrom in theprior discourse
or spatio-temporalcontext (c.f. [Bie01, WJSK03]) . Someexamplesof abstractobjectsmodified
by theseadjectivesareshown in Table3.38.
Table3.38: InternalArgumentwith Comparative/Superlative Adjective
# PP Adverbial # PP Adverbial # PP Adverbial
1 to betterpurpose 1 with greaterprecision 1 on furtherreflection1 in broadestterms 1 with minor exceptions 2 in theshortrun1 in earlierreshufflings 1 on adeeperplane 1 for smallernewspapers
130
![Page 148: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/148.jpg)
Therearesimilarcasesfoundin ourcorpuswherethemodifiedelementis left implicit andthere
is oftenno determiner. Someexampleareshown in Table3.39; thesewill bediscussedfurther in
Section3.6.
Table3.39: InternalArgumentwith OtherSet-Evoking Adjectives
# PPAdverbial # PPAdverbial # PP Adverbial
18 in general 1 in themain 41 at least17 in particular 2 on thewhole 11 asusual3 atbest 1 atworst 13 in short
While thereis amuchmorevariedarrayof adjectivesdisplayedin ourcorpusthanthereis space
to cover here,majorclasseshave beendiscussedwhich causeabstractobjectsto refer to theprior
discourse.Many of theotheradjectivesin ourcorpus(in additionto someof thosediscussedabove),
fall to a greateror lesserextentinto theadverbmodificationtypesdiscussedin Section3.3.
3.5.5 Other Ar guments
S and PPsare also found as internal argumentsof the PP adverbials in our corpus. Moreover,
in addition to internal argumentmodifiers, thereare also adverb modifiersof the P headitself.
The remainderof our corpusconsistsof complex combinationsof the internalargumentsalready
mentioned.Corpuscountsof thesetypesareshown in Table3.40.
Table3.40:ApproximateCountsof TokensandTypesof someInternalPParguments
# Tokens # Types Inter nal Ar gument
692 679 S arguments192 180 PParguments166 166 ADVP modifiers2526 2361 complex combinations
For our purposes,the analysisof PPinternalargumentsis identical to the analysisof the PP
modifiersdescribedabove,with respectto abstractobjectsanddistinguishingdiscourseandclausal
adverbials. However, becauseannotatorsfrequentlyconfusePPadverbialscontainingPPinternal
131
![Page 149: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/149.jpg)
argumentswith ADVP adverbials,we will investigatesomeparticularcasesin the next section.
AnnotatorsalsofrequentlyconfusePPadverbialscontainingadverb-modifiedP headswith ADVP
adverbials;thesetoowill bediscussedin thenext section.
Also for ourpurposes,S-modifyingphrasestakingS internalargumentssimplyprovideanother
form in whichtwo AO interpretationsarerelated.However, basedonthePennTreebankI POStag-
ging andbracketingguidelines,all PPadverbialstakingS argumentsshouldnot have beenpresent
in our data. For thoughPennTreebankPOStagsmake no distinctionbetweenprepositionsand
subordinatingconjunctions(both aretaggedasIN), the argumentto the latter is a clauseandthe
entirephraseis bracketedasa subordinatingclause[PT]. However, anexplicit list of subordinating
conjunctionsis not provided. In [Lit98], a subordinatingconjunctionis definedasa linguistic form
that makesa clausea constituentof anotherclause,and the list of subordinatingconjunctionsis
viewedasa researchquestion;[Lit98] identifies107mainentriesand374sensesfor subordinating
conjunctionsin aWebster’s dictionary, includingprepositional,adverb,andverbphrases.
Roughlyhalf of our S argumentscontaineda verb participleand lacked a subject,andwere
parsedasreducedclauses.Someshorterexamplesareshown in Table3.41.
Table3.41:PPAdverbialwith ReducedClauseInternalArgument
# PP # PP
1 afterbeatingthem 1 without sayingso1 asalreadynoted 1 for winning2 asexpected 3 in doingso1 asmight beexpected 1 in sodoing2 aspreviously reported 1 on delvingdeeper
Thesecasesareinterestingbecauseit canbe difficult to decidewhetherto treatsomephrase
asreducedclausesor sub-clausalconstituents,especiallywhenmodifiedby a prepositionthatalso
functionsasa subordinatingconjunction.This is particularlyan issuefor argumentslackingboth
a verbanda subject,suchas“while in hiding” or “as usual”. Moreover, somelexical items,such
asas, canbe both prepositionsandadverbs(e.g. twice as long). Adverbscanmodify verbs,and
thuswe could representphrasessuchasas expectedeitherassubordinatingclausesor asADVP
132
![Page 150: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/150.jpg)
adverbials. [Kno96], in fact, treatsthis expressionasan adverbial discourseconnective without
consideringits composition. He doesnot, therefore,addressthe closely-relatedPP, as might be
expected, or its numerousotherpossiblevariations.
TheremainingPPadverbialsin our corpusconstitutecasesthatcombinethemodificationand
argumenttypesdiscussedabove,includingmultiplemodifications,coordinatedphrases,andrelative
clauses,etc.And again,theirsemanticfunctionasdiscourseor clausaladverbialscanbedetermined
accordingto their composition,asdiscussedabove.
3.5.6 Summary
Table3.42:PPAdverbialSummary
Inter nal Ar gumentType PP Adverbial
propernoun in New Yorkanimatepronoun to mepotentialDD afterthatdefiniteAO at thetimedemonstrative AO for thatreasonindefiniteAO withhiddenAO argument asa result(of that)indefiniteAO withhidden � AO � argument asanexample(of that)definiteAO withhidden � AO � argument at thevery least
In thissectionsaw thatthemajority of PPdiscourseadverbialsdo notoccurfrequently. Rather,
therearea few “stock” discourseconnectives,suchasas a result, anda wide variety of otherPP
adverbialswhich containa semanticargumentthatmustberesolvedto anAO interpretationin the
prior discourseor spatio-temporalcontext. We have presenteda wide variety of abstractobjects
found in our corpusof PP adverbials. We have shown that PP clausalanddiscourseadverbials
canbedistinguishedby theinterpretationthesemanticargumentsthey contain.We have presented
a variety of semanticmechanismsthat cancausetheseargumentsto be interpretedwith respect
to the discourseor spatio-temporalcontext. Ignoring the openquestionof small clauseinternal
arguments,asummaryof somebasicmechanismswhichcancausetheseargumentsto referencean
133
![Page 151: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/151.jpg)
abstractobjectin thesurroundingcontext areshown in Table3.42.
3.6 S-Modifying ADVP Adverbials
As discussedin Section3.2,andrepresentedin Figure3.6,S-modifyingADVP adverbialsadjointo
anexternalS argumentandarefrequentlycomposedof a singleadverbhead,but mayadditionally
containaninternalargumentandoneor morespecifiers.
SÍ Í Í ÍÎÎÎÎADVP� � � �ÝÝ����
Spec ADV Arg�6�* S
Figure3.6: SyntacticStructureof S-Modifying ADVP Adverbials
In prior sectionswe saw [Moo93]’s useof predicatelogic to representS-modifying ADVP
thattakeonly onesemanticargument;hereweillustratetheinterpretationof suchADVP in lambda
calculus(c.f.[HK98]) asshown in (3.96),usingtheADJ (or NP)derivativeof theadverbto represent
thepropertyadjective they supplyto their (external)semanticargument� . For example,if wise is
taken to representthepropertysuppliedby theadverbwisely, thentheinterpretationof theADVP
wiselycanberepresentedasin (3.97). We resolve � to thesemanticinterpretationof theexternal
S argument. If engage(j,s) is taken to representthe semanticinterpretationof the sentenceJohn
engagedthesafety, thentheinterpretationof theS-adjoinedADVP adverbial is asin (3.98).
(3.96)[[ADVP]] = ß y.adjective(y)
(3.97)[[wisely]] = ß y.wise(y)
(3.98)[[Wisely, Johnengagedthesafety]]= wise(engage(j,s))
If we exchangewise for additional, however, we producethe interpretationof the discourse
adverbialadditionally. In theremainderof this sectionwe focuson how thesemanticmechanisms
underlyingtheinterpretationsof theadverbsin ourcorpusdistinguishADVP clausalanddiscourse
adverbials. We will show that many S-modifying ADVP adverbialstake an additionalsemantic
134
![Page 152: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/152.jpg)
argumentandcanberepresentedasbinarypredicates,andwewill alsoseemorecomplex semantic
representationsfor certainadverbs. However, the ADVP adverbialsin our datasetarea motley
crew, dueto thewide variability of adverbs.For example,while many adverbsconstituteanentire
ADVP (e.g.carefully), a largenumberof ADVP adverbialsin ourcorpuscontainadverbsmodified
by anotheradverb(e.g. more carefully) thatcanalsoaffect their interpretation.Moreover, we find
frequenttaggingerrorsin ourADVP corpuswhichserveto illuminatetheinterpretationsof adverbs,
asthey displaypatternsalsocommonto correctlytaggedADVP adverbials.
3.6.1 Syntactically Optional Ar guments
Approximatecountsin ourcorpusof thetokensandtypesof theADVP adverbialsdiscussedin this
sectionareshown in Table3.43.
Table3.43:ApproximateCountsof TokensandTypesof someADVP Adverbials
# of Tokens # of Types Category
85 55 PP-like ADVP with optionalarguments78 18 relationalADVP with optionalarguments
Therearea numberof constructionsin our ADVP corpusthat shouldhave been(and in our
PPcorpushave been)taggedasPPadverbials.Someexamplesareshown in Table3.44. Thefirst
columnlists theinitial preposition-preposition construction(COMB); whenthesecondpreposition
varies,we list it asP. Thesecondandthird columnsindicatethenumberof timesthis combination
wastaggedasPPandADVP, respectively. Thelastcolumnprovidesacorpusexample.
Table3.44:Mis-TaggedPPAdverbials
COMB # PP # ADVP Example
asP 94 3 asfor themeritsbecauseof 12 54 becauseof thisexceptfor 12 1 exceptfor theembarrassmentprior to 4 6 prior to that
TheasP constructionis likely mistaggedasanADVP dueto theuseof theadverbas in other
135
![Page 153: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/153.jpg)
constructionsdiscussedbelow. Thebecauseof andexceptfor constructionsmaybemistaggedas
ADVP adverbialsdueto their similarity in form to theADVP constructionshown in Table3.45,in
whichanADVP adverbialtakesanoptionalPP. TheseADVP adverbialswerealsomistaggedasPP
adverbials,asshown.
Table3.45:PP-likeADVP Adverbialswith Overt Arguments
COMB # PP # ADVP Example
insteadof 7 37 insteadof thatratherthan 2 11 ratherthantemptpeopleto buy moreregardlessof 0 5 regardlessof rightsandwrongs
However, asshown in Table3.46, andunlike the PPinternalargumentsof the PPadverbials
shown in Table 3.44, the PP of theseADVP adverbialsare syntacticallyoptional. Although as
shown regardlessdoesn’t occurin ourcorpus(sentence-initially) without its accompanying PP, this
authorrecentlyheardsuchauseonNationalPublicRadio.
Table3.46:PP-like ADVP Adverbialswith HiddenArgument
# ADVP Adverbial
18 instead14 rather0 regardless
TheseADVP adverbialscanberepresentedasbinarypredicates,akin to PPadverbials. How-
ever, recall that [Bie01, McC88] do not treattheoptionalthanPP in other thanphrasesasa com-
plement,but ratherasan adjunct,and[Bie01] thenusestheAI heuristic“useexisting objects”to
resolve thehiddenargumentto theinternalargumentof thePP. While therepresentationof this PP
mayvary dependingon thechosenformalism,we neverthelessarguethat theseADVP adverbials
take a definitehiddensemanticargument. Moreover, the interpretationand/orresolutionof this
hiddenargumentcanbeanconcreteobject,anabstractobjectNP, or anabstractobjectreifiedfrom
a VP or S in theprior discourse.(3.99)- (3.101)show thatalthoughtheargumentcanbe explicit
or implicit (a-b cases)andstill resolve to theAO interpretationof VP or S, themodifiedsentence
136
![Page 154: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/154.jpg)
cannotbeinterpretedif theargumentis not resolvablein thediscourseor context ( i cases).
(3.99a) I wantedto go to themovies. Insteadof that,I wentto work.
(3.99b) I wantedto go to themovies. Instead,I wentto work.
(3.99c) *Instead,I wentto work.
(3.100a)Michaelwon’t studybiology. Ratherthanthat,hedreamsaboutit.
(3.100b) Michaelwon’t studybiology. Rather, hedreamsaboutit.
(3.100c) *Rather, Michaeldreamsaboutbiology.
(3.101a)Mary might wantto comeby today. Regardlessof that,I’m goingto themovies.
(3.101b) Mary might wantto comeby today. Regardless,I’m goingto themovies.
(3.101c) *Regardless,I’m goingto themovies.
Regardingtheprior to constructionshown in Table3.44,thereareothersimilar constructions
taggedasADVP adverbialsin our ADVP corpus,shown alongwith their countsin Table3.47.All
of theseconstructionscontainrelationaladjectives with overt PParguments. [MW] lists all five
constructionsas(complex) prepositionalphrases.Only prior to is containedin our PPadverbial
corpus,however while all fivewerecontainedin ourADVP adverbialcorpus,albeitonly once.
Table3.47:RelationalADJPwith Overt Argument
# Relational ADJP
1 contraryto theseexpectations1 dueto theearthquake in SanFrancisco1 irrespective of theoutcomein centurieselapsedsincesplitting1 shortof fleeingto Warrenton,Virginiaor Rockville,Maryland1 subjectto certainconstitutionalrestraintsin favor of fair trials
As discussedin Section3.2,many adverbsarederived from adjectivesor nouns;someADVP
discourseadverbials,not surprisingly, containadverbsderived from relationaladjectivesor nouns.
Somecorpusexamplesareshown in Table3.48.Thethird columnshowsthe(or oneof thepossible)
relationalnounor adjective from which eachadverbis derived,alongwith a demonstrative instan-
tiation of its argument. Most adverbsderived from relationalnounsor adverbssoundawkward
with thisargumentmadeexplicit, andthusdon’t appearin ourcorpus.Simultaneouslyhowever did
137
![Page 155: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/155.jpg)
appearin the corpuswith an overt PPargument,asshown (partially) in the third column. Many
of theserelationalnounsandadjectivesalsohave correspondingPPadverbials(e.g. in addition to
this).
Table3.48:RelationalADVP Adverbialswith HiddenArgument
# Relational ADVP Relational ADJP/NP Derivative
12 accordingly accordingto this3 additionally additionalto this1 alternately analternateto this1 analogously analogousto this8 consequently aconsequenceof this5 conversely aconverseto this1 contrarily contraryto this3 currently currentwith this6 incidentally incidentalto this12 recently recentto this2 previously previousto this2 separately separatefrom this12 similarly similar to this8 simultaneously simultaneouslywith theanodesurfacetemperature....1 subsequently subsequentto this
We saw in theprior sectionthatmakingtheoptionalargumentof a relationalnounexplicit can
move the burden(of classifyingthe adverbial asa discourseor clausaladverbial) to this explicit
argument,becauseit cantake a variety of forms thatmay or may not dependon context for their
interpretation,andmay or may not be an abstractobject. The samevariety canbe displayedby
theexplicit optionalargumentsof theserelationaladjectives. Interestingly, simultaneouslycanfind
both argumentswithin the clauseit modifies,as in (3.102a), wherethe eventsof Mary hearing
thenoiseandMary’s husbandhearingthenoiseareinterpretedassimultaneous. Thecoordinating
conjunction,which alsoassertsthetwo eventssemanticallyandtakesbothargumentsstructurally,
mayplayarolehere;see[CFM�
02] for discussion.Thesameuseof simultaneouslycanalsoresolve
its hiddenargumentto theprior discourse,asin (3.102a), whereFredseeinga bright flashcanbe
interpretedastheevent that is simultaneouswith theevent(s)of Mary andher husbandhearinga
noise.Discussionof clause-internalresolutioncanalsobefoundin [WJSK03] andChapter4.
138
![Page 156: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/156.jpg)
(3.102a)Simultaneously, Mary andherhusbandheardanoise.
(3.102a) Fredsaw abright flashof light. Simultaneously, Mary andherhusbandheardanoise.
3.6.2 Context-DependentADVP Adverbials
Approximatecountsin ourcorpusof thetokensandtypesof theADVP adverbialsdiscussedin this
sectionareshown in Table3.49.
Table3.49:ApproximateCountsof TokensandTypesof someADVP Adverbials
# Tokens # Types Category
687 134 PP-RelatedADVP919 26 DeicticADVP
Justaswe saw in our PPcorpus,in our ADVP corpustoo therearea few cases,exemplifiedin
(3.103),wherea subordinatingconjunctioncontainingan internalS argumentandmodifying anS
is misparsedasanADVP adverbial. In many othercasesfoundin ourADVP corpus,however, such
a conjunctionappearssentence-initiallyandthe modifiedS is its internalS argument. The other
conjoinedclauseis to befoundin theprior discourse.Countsof suchcasesareshown in Table3.50.
(3.103)Onceyou getthefeelof it
Table3.50:ADVP AdverbialConjunctions
# ADVP Conjunction # ADVP Conjunction
2 although 15 though212 however 1 unless88 so
Thesecasesaregenerallyviewed as adverbials(and thusmay be correctly tagged,although
PennTreebankdoesnot explicitly indicatetheir treatment),becauseoneargumentis not structural
(with respectto thesentencestructure).DLTAG currentlytreatstheadverbialhowever (andlikely
theothersaswell) asananaphoricdiscourseconnective. Theform of theseadverbialscannotbede-
composedwithout a sincerehistoricalanalysis;they neverthelessclearlyrequireinformationin the
139
![Page 157: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/157.jpg)
prior discoursefor their interpretation.Only with however, asshown in (3.104),doesthemeaning
changesperceptiblybetweenthetwo forms. Its meaningasa subordinatingconjunction(3.104a)
conveys a “manner”,while its meaningasanadverbial(3.104b) conveys denialof expectation(c.f.
[Kno96])22. Theremay alsobe a differencein the temporalorderingbetweenthe two; the event
modifiedby adverbialhowever is interpretedasoccurringafter the theeventdescribedin thefirst
sentence,while the event modifiedby conjunctive however is interpretedasoccurringbefore the
eventdescribedin thefirst sentence.
(3.104a)Johncannotseemto learnto tie his shoes,however (much)hetries.
(3.104b) Johncannotseemto learnto tie his shoes.However, hetries.
Also aswe saw in our PPcorpus,many subordinatingconjunctionsfunctionasPPadverbials
whentheir internalargumentis asub-clausalconstituent.TwelvesuchcasesaremisparsedasADVP
adverbialsin ourADVP corpus;in fivecasesthereis aprecedingadverbmodifying thepreposition
head.An exampleis shown in (3.105)
(3.105)ShortlyaftertheValeincident
However, threelexical itemsthat function assubordinatingconjunctionsandprepositionsare
alsofound in our corpusfunctioningasadverbs,in that they appearwithout an internalargument
andin [MW] aretreatedasadverbs(whenmodifying VP or S). For our purposes,theseadverbials
containdefinitesemanticargumentsthatmustbe resolved to informationin theprior discourseor
context. In our corpusthesecasesoccursix times,alwayswith a specifier. Threeexamplesare
shown in (3.106)-(3.108).Moreover, theprepositionafter alsohasansynonymousadverbial form
in which the internalargumentis hidden,shown in (3.109),which occursin our corpusfour times
andwhosehiddenargumentis, like theothers,anaphoricto informationin thediscourseor context.
(3.106)Twentyyearsbefore
(3.107)Shortlyafter
(3.108)Eversince
(3.109)Afterwards
22It would beinterestingto tracethedevelopmentof thesetwo distinctinterpretations.
140
![Page 158: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/158.jpg)
Similarly, therearelexical itemsthatdon’t functionassubordinatingconjunctionsbut do func-
tion asprepositions,andthatarefoundin ourcorpusfunctioningasadverbs,in thatthey tooappear
without anovert internalargument.Again, this informationmuststill beresolved in theprior dis-
courseor context. One item, shown in (3.110),appearstwenty-four times. Therearenumerous
otherexamplesthatoccuronceor twice, includingbelow, throughout,outside23, althoughthelastis
ambiguouslya noun24.
(3.110)Besides
Althoughsyntactically, prepositionsthatmodify aVP or Smaybetreatedasadverbswhentheir
syntacticargumentis missing25, at thesemanticlevel thereis no reasonto changetheir representa-
tion; in thelattercasetheir hiddenargumentsimply doesn’t comestructurally.
[Bie01] provides a semanticanalysisof “Xs besidesY” (e.g. other search enginesbesides
BidFind) asan alternative phrasethat is similar to his treatmentof the phrase“other Xs thanY”;
otherandbesidesin theseconstructionsexcludeX (theground) from Y (thefigure) andpresuppose
that both X andY belongto the samesetof alternatives. However, while Biernerconsidersthe
anaphoricform, “other Xs”, whereY is resolved anaphorically, he only considersthe structural
form of besides, not caseswhereY is implicit, becausehe only studiedsub-clausalmodification,
andthis doesnot occurwhenbesidesmodifiessub-clausalconstituents.It doesoccur(twenty-four
timesin ourcorpus),however, whenbesidesmodifiesS.An examplefrom WSJis shown in (3.111).
(3.111)Mr. Langsayshe isn’t scoutingnew acquisitions,at leastfor now. “We would have to
go outsideto banksto get the money andI am not readyto do that,” he said. “Besides, we have
enoughon ourplate.”
Y, theinternalargument,couldhave beenexplicit, e.g.besidesthat. Bierner’s semanticsmayapply
to S-modifyingbesides; in this case,however, the figurewould be an AO from thediscoursethat
is excludedfrom a largerpresupposedsetof AOs,ratherthananconcreteobject. For example,in
(3.111), the useof besidesappearsto invoke a setof reasonswhy Mr. Lang isn’t scoutingnew
23see[Par84]for a discussionof such“context-bound”modifiers.24A few (frequentlymistaggedasADVP) nounscanmodify S,asdiscussedin Section3.2,(e.g. thisyear).25andit is not clearfrom PennTreebankor [MW] thatthis is alwaysthecase
141
![Page 159: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/159.jpg)
acquisitions,including Y from the context (having to go outsideto banks),and the modified X
(having enoughon our plate). ExtendingBierner’s semanticsto S-modifyingbesidesrequiresan
annotationstudy, however, suchasthatdescribedin Chapter4.
Frequently, misparsedPPadverbialsfoundin our ADVP corpusarethosein which a particular
prepositionheadis modifiedby a particularadverb26. Table3.51exemplifiessuchconstructions.
Thefirst columnlists thephrase-initialadverb-prepositioncombination(COMB); whenthesecond
prepositionin the combinationvaries,we list it asP. The secondandthird columnsindicatethe
numberof timesthis combinationwastaggedasa PPandanADVP, respectively. Thelastcolumn
providesanexampleof theconstructionasfoundin thecorpus.
Table3.51:Mis-TaggedPPAdverbialConstructions
COMB PP ADVP Example
away from 0 2 away from thegeneralobligationsectoralongwith 9 3 alongwith thenoteapartfrom 3 8 apartfrom racialproblemsasidefrom 10 8 asidefrom thisbackP 4 9 backin theU.S.A.earlyin 7 7 earlyin herlifeelsewherein 1 2 elsewherein theoil sectorfar P 1 6 far from beingminimalist
In [MW], someof theseconstructionsarelistedas(complex) prepositionalphrases.However
mostPP-modifyingadverbsarealsofoundmodifyingadverbsandnounsin ourcorpus,asshown in
(3.112)-(3.114);far is specifiedby theanaphoricso, creatinganoft-usedphrase.
(3.112)Backthen
(3.113)Immediatelythereafter
(3.114)sofar thismonth
More interestingfor our purposes,however, is the fact that many of thesemodifying adverbs
canalsooccuraloneor with only a specifier, in which casethey areinterpretedasspatio-temporal
26alongalsofunctionsasa preposition,sothis couldbea PPadverbialcontainingan internalPPargument;however,it is similar in meaningto theothersincludedin this table.
142
![Page 160: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/160.jpg)
anaphorsor deixis,or equivalentlyashaving a hiddenargumentthat is interpreteddespitethefact
thatit is notovert,asexemplifiedin Table3.52.
Onesimilar adverb,ago, can’t modify a preposition,only anNP; moreover, it requiresa spec-
ifier. It appeared132 timesin our corpuswith 71 differentspecifiers.NP modificationandsome
morecommonspecifiersareshown in Table3.53.
Table3.52:Spatio-TemporalADVP Adverbials
# ADVP Adverbial # ADVP Adverbial
1 ascanthalf mile away 3 almostimmediately1 acoupleof yearsback 2 immediately2 elsewhere 2 prettysoon2 shortly 6 thusfar15 soon 32 sofar
Table3.53:AnotherSpatio-TemporalADVP Adverbial
# ADVP Adverbial # ADVP Adverbial
1 ayearagothis fall 12 two yearsago1 seventeenyearsagotoday 8 two weeksago13 ayearago 7 a few yearsago
TheseADVP, alongwith theothertemporalS-modifiersin Table3.52andthosein Table3.54
whicharenotalsousedasmodifiers,supplytemporalinformationto themodifiedclausethey mod-
ify in relationto someothertemporalinformation.
Table3.54:OtherSpatio-TemporalADVP Adverbials
# ADVP Adverbial # ADVP Adverbial
14 already 10 presently24 meanwhile 7 eventually
Thisothertemporalinformationcanberesolvedanaphorically, asin (3.115),whereimmediately
refersto the time after the storefiled for bankruptcy, or resolved deictically, as in (3.116)(from
WSJ),whereimmediatelyrefersto the time right after the time the text wasread.For example,if
143
![Page 161: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/161.jpg)
thisdiscoursewerereadin today’s paper, thenimmediatelywould referto just aboutnow.
(3.115)Thestorefiled for bankruptcy. Immediatelycustomersflockedto its closingsales.
(3.116)This is but oneknot in astringof troubles.Lastyearthestorefiled twicefor bankruptcy.
Immediatelyit will besubjectto foreclosure.
Similar resolutionpossibilitiesarefoundfor modifiersin ourcorpus,exemplifiedin Table3.55,
thatareusuallyviewedas“manner”(VP) modifiers,thoughthey toosupplytemporalfeatures.
Table3.55:Spatio-TemporalMannerADVP Adverbials
# ADVP Adverbial # ADVP Adverbial
1 abruptly 1 instantly2 briefly 1 quickly7 gradually 6 slowly1 hastily 23 suddenly
Adopting Ernst’s distinctionbetweensituation (S) modificationandevent (VP) modification
discussedin Section3.4,we find thatthesemodifierscaneitherrelatethetwo temporalboundaries
of theevent,or canrelatetheinitial temporalboundaryof thesituationanda time in thediscourse
or context For example,in (3.117),quickly caneithermeasuresthe time betweenraisingthe eye
dropperandblinking, or the time betweenthestartandfinish of blinking. Briefly, moreover, can
relatethetwo temporalboundariesof aspeechact,asshown in (3.36),repeatedfrom Section3.3.
(3.117)Thedoctorraisedtheeyedropper. Quickly Johnblinked.
(3.36b) (YouaskedmewhatJohnsaid.)Briefly, Johnsaidhewouldstopby.
We have beenaddressingadverbsthathave ananaphoricor deicticquality with respectto the
fact that they mustbe interpretedwith respectto thediscourse27, equivalently viewed asa hidden
semanticargument. True deixis, however, is also frequently found in our corpus,as shown in
Table3.56alongwith their counts28. Therearealsocasesin our corpusin which thesedeicticsare
mistaggedPPmodifiers(e.g.here in Morgenzon...), or arethemselvesmodified(e.g.right now).
27see[Par84]for furtherdiscussion28PennTreebanktagstoday, tomorrow etc.asNPs,although[MW] views themasadverbs.
144
![Page 162: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/162.jpg)
Moreover, from many of thesedeictics(e.g. hence, then, still, yet, thus) have beenderived
homonymousrelationaldeixis(discourseadverbials);mostof theoccurrencesin ourcorpusof these
homonyms likely correspondto their discourseadverbial use. The differencebetweentheseuses
is illustratedusing then in (3.118)29. In (3.118b), thenordersthe event it modifiesin a temporal
sequencerelationwith theeventdescribedin (3.118a). In (3.118c), thenmakesdiscoursedeictic
referenceto theeventdescribedin (3.118a) andtheit-cleft assertsthatthetemporalcoordinatesof
thiseventarethesameasthetemporalcoordinatesof theeventdescribedin (3.118c).
(3.118a)JohnandMary haddinner.
(3.118b) Thenheaskedherto marryhim.
(3.118c) It wasthenthatheaskedherto marryhim.
Table3.56:DeicticADVP Adverbials
# ADVP Adverbial # ADVP Adverbial
26 hence 41 still59 here 114 thus189 now 3 today292 then 1 tomorrow39 there 80 yet
Frommany of thesedeicticsstill otherotherdeicticsandrelationaladverbshave beenderived
aswell, asdiscussedin [Kno96]. Thosefoundin ourcorpusareshown in Table3.57.
Table3.57:Deictic-DerivedADVP Adverbials
# ADVP Adverbial # ADVP Adverbial # ADVP Adverbial
1 hereby 4 thereafter 1 therefore1 heretofore 1 thereby 1 therein1 nowadays 47 therefore 1 thereupon1 thenceforth
[Kno96, WJSK03]provide detaileddiscussionsof the lexical semanticsof the discoursead-
verbialsin thesetables.That many have retainedtheir deicticquality is exemplifiedin (3.118b),
29This distinctionwasoriginally pointedout by Dr. EllenPrinceto theDLTAG group
145
![Page 163: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/163.jpg)
wherethediscourseadverbialcanalsoretrieve therelatedAO from thespatio-temporalcontext. For
example,supposetwo parentsarewatchinga child playing in mudat theplayground.Oneparent
canmake thecommentin (3.119),retrieving this AO from thevisualcontext.
(3.119)“Then/Thereforehe’ll comerunningover hereandputhis handsall over me.”
3.6.3 ComparativeADVP
Approximatecountsin ourcorpusof thetokensandtypesof theADVP adverbialsdiscussedin this
sectionareshown in Table3.58.
Table3.58:ApproximateCountsof TokensandTypesof someADVP Adverbials
# of Tokens # of Types Category
384 110 Atomic Comparatives77 77 Comparative Constructions
NumerousADVP adverbialsin ourcorpusarecomparativeor superlative,andthusby definition
dependentin anidiosyncraticway on referenceto at leastoneotherobjectin theprior discourseor
spatio-temporalcontext (c.f. [Bie01, WJSK03]). In somecases,a comparisonis madebetween
abstractobjects.Most of thecomparativesadverbsin our corpusaretemporalcomparatives. Fre-
quently, they appearmodifying anS-modifier;themodifiedheaddetermineswhatpropertiesof the
objectsarebeingcompared(e.g. equallyoften), or mayclarify thesourceof thecomparison(e.g.
earlier (thanthat) this year). Someexamplesareshown in Table3.59.
Table3.59:Comparative AdverbModifiers
# ADVP Adverbial # ADVP Adverbial
15 earlierthis year 1 laterthatday1 farthersouth 10 morerecently1 equallyoften 5 mostrecently
Somecomparatives(e.g. farther) don’t appearat all asS-modifiers;othersdo, exemplifiedin
Table3.60. In a few instancestheelementwhosepropertiesarebeingcomparedwith thoseof the
146
![Page 164: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/164.jpg)
modifiedS is madeovert with a PP, asshown in the secondcolumn. The corpusexamplewhere
more appearaloneis shown in (3.120);it comparestwo AOs,oneis reifiedfrom theinterpretation
of a clausein theprior context, andappearssynonymouswith moreover, discussedbelow.
(3.120)Within theOrganizationof AmericanStates,theremaybesomecriticismof thisunilat-
eralAmericaninterventionwhichwasnotwithout risk obviously. But therewasnocomplaintfrom
theDominicancrowdswhich lined CiudadTrujillo’ s waterfrontshouting,“V ive Yankees”! More,
theU.S.actionwashailedby aprincipaloppositionleader, Dr. JuanBosch,ashaving saved“many
livesandmany troublesin thenearfuture”. (Brown)
Table3.60:Comparative ADVP Adverbials
# ADVP Adverbial # ADVP Adverbial
2 earlier 1 evenearlierthanthat30 later 0 laterthanthat13 further 0 furtherthanthat1 more 2 morethanever
Morefrequentlyin ourcorpus,comparativeADVP S-modifiersoccurwith avarietyof specifiers
thatclarify theextentof thecomparison.Suchcasesoccur111times;in all but six theadverbhead
is earlier or later. Someexamplesareshown in Table3.61.
Table3.61:SpecifiedComparative ADVP Adverbials
# ADVP Adverbial # ADVP Adverbial
16 ayearearlier 1 muchbetter5 oncemore 7 ayearlater
Therearealsoadverbsin ourcorpusthatcannotmodify othermodifiers,but thatmayhavebeen
derived from comparatives,asshown in Table3.62. Whethertheir internalcomparative accounts
for their behavioral anaphoricityis anopenquestion.It is neverthelessclearthattheseS-modifiers
requireanAO from thecontext for their interpretation,andin somecaseswe canmake their hid-
denargumentovert (e.g. otherwisethan that). The lexical semanticsof someof thesediscourse
adverbialsarediscussedin [WJSK03, WJSK99, Kno96].
147
![Page 165: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/165.jpg)
Table3.62:Comparative-DerivedADVP Adverbials
# ADVP Adverbial # ADVP Adverbial # ADVP Adverbial
31 furthermore 53 moreover 3 nonetheless4 likewise 36 nevertheless 19 otherwise
Also in are corpusare various instantiationsof a comparative constructionof the form “asÛ adverbt as”, wherethe inner as PPtakesan S, NP, or othersub-clausalelementasargument.
50 occurrencesof this constructionarefound in our ADVP corpus;2 arefound in our PPcorpus.
Someinstantiatedforms areshown in Table3.63, alongwith their (ADVP) corpuscountsanda
corpusexample.Therearealsofive relatedconstructionsexemplifiedin thebottomsectionof the
table.“Justas” and“insofar as”alsoappearedin ourPPcorpus.
Table3.63:Comparative Constructions
# Construction Examples
1 ascheerfullyas ascheerfullyaspossible6 asearlyas asearlyas17768 asfar as asfar asi amconcerned10 aslong as aslong asthispoint of view prevails12 assoonas assoonasthetremorpassed1 assurelyas assurelyasaseesaw tilts4 aswell as aswell asin theme9 sofar as sofar asi know3 insofar as insofar assciencegeneratesany fear3 solong as solong asdeathwasnot violent12 justas justasin thecaseof every prodigychild7 nomatterWH no matterhow hot theday
In all cases,thephraseprecedingthe internalas (or WH) phrasefunctionsasanADVP; there
is someambiguity however as to whetherthe ADVP takes an internal argumentor the internal
phrasetakes an ADVP modifier; the category of theseconstructionsvariesin the literature. In
PennTreebank,the “as Û adverbt as” constructionsare taggedas ADJP when they function as
sub-clausalmodifiers,asin (3.121),andasNP whenthey functionasargumentsto transitive verbs,
148
![Page 166: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/166.jpg)
asin (3.122).
(3.121)Mary is astall asJohn(is tall).
(3.122)They yieldedasmuchas20%of theexpectedamount.
However, [MW, Lit98, PT] all treataswell asasa coordinatingconjunction,and[Lit98] also
treatsthe no matterWH constructionalongwith someof the “as Û adverbt as” constructionsas
subordinatingconjunctionswhentheinnerphraseis anS.As mentionedin Section3.5,thereis also
somequestionasto whetherall argumentsof theinnerasarenotbestrepresentedassmallclauses.
For example,in thesameway thatwe add“is tall” in (3.121)to interpretthecomparisonof Mary’s
andJohn’s tallness,so we addadditionalmaterialto (3.123)to interpretthe comparisonbetween
Michael’s cheerfulnessandthepossibilityof cheerfulness.
(3.123)As cheerfullyas(it is) possible(to entertheroom),Michaelenteredtheroom.
Aswell appearsoncein ourcorpus,shown in (3.124),indicatingthatits semanticargumentcan
beimplicit. A numberof otherinstantiationsof “as Û adverbt as” can,at leastin spokenlanguage,
leave their argumentimplicit, includingasoften, asrecently. (3.125)alsoseemsfelicitous. More-
over, this authorusesthephraseno matterasanS-modifierwithout theaccompanying WH-phrase
anddependsoncontext for interpretation.
(3.124)FrankGilmartin, a traderwho follows insurancestocksfor Fox-Pitt Kelton, saidhis
strategy wasto sell early. Then, if the stocksfell sharply, he plannedto begin buying themag-
gressively, on thetheorythatthecompaniesthatinsureagainstpropertydamageandaccidentswill
have to raiserateseventuallyto compensatefor theclaimsthey will payto earthquake victims and
victims of last month’s HurricaneHugo. As well, reinsurersand insurancebrokeragecompanies
will have improvedprofits. (WSJ)
(3.125)Janesmiledwidely andburstinto laughter. As cheerfully, Michaelbeganto sing.
3.6.4 Setsand Worlds
Approximatecorpuscountsof ADVP adverbialsdiscussedin thissectionareshown in Table3.64.
149
![Page 167: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/167.jpg)
Table3.64:ApproximateCountsof TokensandTypesof someADVP Adverbials
# of Tokens # of Types Category
137 16 Ordinal184 29 Frequency279 19 Epistemic56 31 Domain151 49 Non-Specific263 96 Evaluative/Agent-Oriented
Therearea numberof ordinalADVP in our data. Althoughonly first co-occurswith anovert
PP(first of all occurred6 times)30, thesecondcolumnof Table3.65shows thatotherscanaswell.
Table3.66shows synonymous-ly counterpartsof suchordinals.
Table3.65:OrdinalADVP Adverbials
# ADVP Adverbial Explicit Set
34 first first of all12 second secondof all7 third third of all3 fourth fourthof all1 last lastof all6 next next to that
Table3.66:Ordinal-ly ADVP Adverbials
# ADVP Adverbial # ADVP Adverbial
5 secondly 1 lastly1 thirdly 47 finally
Ordinalsindicatetheorderof themodifiedelementin a largerset.Semanticallythis setcanbe
representedasa hiddenargument,which may or maynot be madeexplicit with a PPandmayor
maynotberesolvedto a setof abstractobjectinterpretationsof VP or S in theprior discourse.For
30next to NPalsooccurredtwice,e.g.“next to theocean”;this interpretationyieldsa spatialordering,however.
150
![Page 168: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/168.jpg)
example,in (3.126a), therelevantsetis interpretedasthereasonswhy Mary is a spacecadet,and
in (3.126b), therelevantsetis interpretedastheNP manythings.... Also requiredin thesemantics
of ordinalsis representationof placementin theset.For example,onsecondthoughtrequiresafirst
thought,third of all requirestwo prior elements,andnext requiresat leastoneprior element.
(3.126a) Mary is a spacecadet.First (of all thereasonswhy), shealwaysforgetsto buy milk
for themorning.
(3.126b) I wantto do many thingstoday. First (of all thosethings),I wantto buy milk.
OtherADVP adverbialsin ourcorpusthatinvoke setsare“frequency” ADVP adverbials.Some
examplesoccurringaloneandotherwith adverb modifiersareshown in Table3.67. At times,as
usual, from our PP corpus,are also frequency adverbials. Unlike ordinals,however, frequency
adverbialsinvoke a particulartypeof set:a setof times. But they evoke this settheway quantifiers
suchasfew, all evokesets;althoughthenumberof elementscontainedin thesesetsmaybespecified
(e.g. alwaysversusoccasionally), the setandits elementsmay but neednot resolve in the prior
discourse.Frequency adverbialshave received a variety of semantictreatments;in [Roo95b], for
example,setsof timesareequivalentto events.
Table3.67:Frequency ADVP Adverbials
# ADVP Adverbial # ADVP Adverbial # ADVP Adverbial
4 frequently 19 once 14 usually2 always 2 twice 1 almostdaily8 occasionally 8 occasionally 37 again19 often 49 sometimes 2 all toooften
“Epistemic”ADVP adverbialshave alsobeenanalyzedasinvoking sets.Someexamplesfound
in our corpusareshown in Table3.68. In truth, in fact, from our PPcorpus,arealsoepistemic
adverbials.Epistemicadverbialsalsoinvoke aparticulartypeof set:asetof possibleworlds, which
are the foundationof a variety of intensionalsemantics(c.f. [HK98]). Setsof possibleworlds,
and the worlds containedthereinmay but neednot resolve in the prior discourse,andepistemic
adverbialsmayspecifythenumberof worldscontainedin theset(e.g.probablyversuspossibly).
OtherADVP adverbialsin ourcorpusthatcanbeanalyzedasevokingsetsare“domain” ADVP
151
![Page 169: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/169.jpg)
Table3.68:EpistemicADVP Adverbials
# ADVP Adverbial # ADVP Adverbial # ADVP Adverbial
83 perhaps 2 possibly 3 unquestionably48 maybe 13 probably 5 really31 actually 22 certainly 5 undoubtedly11 surely 44 indeed 1 truly
adverbials.Someexamplesareshown in Table3.69. In theory, in psychology, from ourPPcorpus,
arealsodomainPPadverbials.Thedomainsinvoked by theseadverbialsareagainnot anaphoric,
but they canbe very idiosyncratic;for example,the logical domain(e.g. wherelogic holds),the
psychological domain,etc. Becausedomainadverbsspecifya particulardomain;alternative do-
mains(where,for example,theassertiondoesnothold)maybeevoked,makingthemfeelmorelike
epistemics;we will explorein Chapter5 how suchalternativescanbeimplicated.
Table3.69:DomainADVP Adverbials
# ADVP Adverbial # ADVP Adverbial # ADVP Adverbial
1 logically 1 literally 1 mathematically6 microscopically 1 physiologically 1 technically1 theoretically 1 visually 2 statistically1 psychologically 1 publicly 1 functionally
On theotherhand,therearea wide variety of ADVP andPPadverbials,exemplifiedin Table
3.70,which saynext to nothingaboutthepropertiesof thesetthey invoke or its elements.Rather,
they specifythecomparativepositionof theelementthey modify to thatset.Someareanalyzedas
focusparticles, particularlythosein thelastcolumn;wewill discussthemin Chapter5.
As discussedin Section3.3, however, many adverbsarenot so easilyclassifiedinto a single
modificationtype. Rather, they seemto have propertiesof numerousmodificationtypes. For ex-
ample,theADVP in thefirst columnof Table3.71areat oncedomainandfrequency adverbs;in
our terms,thesetsthey describehave both temporalandidiosyncraticfeatures.TheADVP in the
secondcolumnsupplylessspecifictemporalinformation,they feelmorelikeepistemics,asdoesthe
152
![Page 170: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/170.jpg)
Table3.70:Non-SpecificSet-Evoking ADVP Adverbials
# ADVP Adverbial # PPAdverbial # ADVP Adverbial
2 basically 2 on thewhole 48 also3 essentially 3 in essence 2 even1 fundamentally 17 in particular 6 just3 specifically 41 at least 6 only3 significantly 1 atworst 11 too1 primarily 3 atbest2 mainly 1 in themain2 mostly 13 in short2 partly 3 in part
PPadverbialcounterpartin general. TheADVP in thethird columnof Table3.71arebothordinals
andtemporal;they describeorderedsetsof timesor events.
Table3.71:Multiply-FeaturedADVP Adverbials
# ADVP Adverbial # ADVP Adverbial # ADVP Adverbial
2 historically 2 ordinarily 5 initially1 traditionally 2 typically 3 originally
11 generally 4 ultimately
Many ADVP adverbialsin our corpuswhich have beenclassifiedas“evaluative” alsoconvey
“domain”, and/or“epistemic”,and/or“spatial” properties.Someexamplesareshown in Table3.72.
Again,we canusesetswith multiply featuredidiosyncraticpropertiesto representthis.
Table3.72:More Multiply-FeaturedADVP Adverbials
# ADVP Adverbial # ADVP Adverbial # ADVP Adverbial
10 clearly 4 ideally 23 obviously13 naturally 1 reputedly 2 hopefully2 evidently 1 conceivably 1 seemingly19 apparently 5 presumably 4 inevitably
“Evaluative” adverbialsarealsoeasilyconfusedwith “Agent-Oriented”adverbials. Someex-
153
![Page 171: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/171.jpg)
amplesareshown in Table3.73alongwith their counts.
Table3.73:Evaluative or Agent-OrientedADVP Adverbials
# ADVP Adverbial # ADVP Adverbial # ADVP Adverbial
2 carefully 2 cautiously 1 convulsively1 deliberately 1 desperately 2 emotionally1 enthusiastically 1 stealthily 1 tardily1 relentlessly 1 gently 1 bluntly
While, asdiscussedin Section3.4,[Ern84] clarifiesthedistinctionbetweeneventandsituation
modification(e.g. Carefully JohnapproachedtheDuchesscarelessly), thereis anotherdistinction
which he overlooksthat canhelp clarify the distinctionbetweenevaluateandagent-orientedad-
verbs.This distinctioncanbeviewedasanadditionalhiddenargument,paraphrasedasto X or, in
X’s opinion. For example,Carefully (in John’s opinion),JohnapproachedtheDuchesscarelessly
describesJohn’s opinionabouthisaction,andthuscarefully is agent-oriented.But Carefully (in the
opinionof all outsideobservers), JohnapproachedtheDuchesscarelesslydescribesanomniscient
opinionaboutJohn’s action(which may or maynot includeJohn’s opinion),andthuscarefully is
evaluative. How the readerresolvesX determinesthe function of theseadverbs. [Swa88]’s view
of not only evaluative andagent-oriented,but alsoepistemicadverbsas Speaker saysADJ(S) is
similar; only thehiddenargumentapproach,however, acknowledgescaseswheretheimplicit X is
resolvedto someoneotherthanthespeaker.
Suchananalysisappliestootherevaluatives,including(not)surprisingly, luckily, (un)fortunately,
miraculously, all of which arefound in our corpus,andsomeof which, alongwith someof those
in Table3.72, are intuitively treatedby [Kno96] asdiscourseconnectives. In otherwords, their
treatmentappearsto bedueto theeffect of this hiddenopinion,namely, thatopinionsareasserted
for a reason. If somethingis assertedto be obvious, or (not) surprising, then thereexists some
reasonthat assertionis made,be it visual or otherwiseapparent,asobviousimplies, or a logical
cause,asinevitably implies. More generally, suchananalysisshouldapplyto all adverbuses.For
example,if somethingis assertedto beprobable, deliberate, obvious, whotheassertionis attributed
to is alsorelevant; it may attributed to a particularsomeone,or to everyone,as is likely the case
154
![Page 172: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/172.jpg)
whensomethingis assertedto be first. Clearly, additionalsemantic(andpragmatic)complexity
is requiredto representthis effect, suchasa semanticswhich incorporatesmutualknowledgeand
speaker’s beliefs(c.f. [LA99, HK98, Hir91]).
3.6.5 Summary
In this section,we’ve presenteda wide variety of ADVP from our corpusof ADVP adverbials.
Using the samesemanticmechanismsasin Section3.5, we’ve arguedthat clausalanddiscourse
ADVP adverbialscanbedistinguishedby the interpretationof theadverbandits hiddensemantic
arguments.We’veseenthatalthoughsuchcasesarenotthefocusof theclause-level ADVP literature
discussedin Sections3.3-3.4,many ADVP adverbialsin our corpuscantake an optionalPPthat
instantiatesthishiddenargument.A summaryof someof themechanismsthatcancauseanADVP
adverbialto requireanentity from thediscourseor spatio-temporalcontext for its interpretationare
shown in Table3.74.
Table3.74:ADVP AdverbialSummary
Type ADVP Adverbial
potentialDD here/nowhiddenNP argument unfortunately(for me)hiddenAO argument consequently(on that)hidden � AO � argument first (aboutthat)
3.7 Conclusion
In thischapterwehaveshown thatin many caseswhathavebeencalled“cuephrases”or “discourse
connectives” arenot an accidentalgroupingof ADVP andPPadverbials; rather, their discourse
propertiesarisenaturally from their semantics.We have shown that whetheror not ADVP and
PPadverbialsfound in a corpusfunction asdiscourseconnectivesandareclassifiedasdiscourse
adverbialsdependsontheinterpretationof theirsemanticarguments.Wehaveshown thatdiscourse
adverbialsarevery similar to discoursedeixis, in that both requirefor their interpretationan AO
155
![Page 173: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/173.jpg)
madeavailablefrom a VP or S in theprior context. In Chapter4 we will discusswaysin which the
semanticframework outlinedherecanbe formalizedandincorporatedinto theDLTAG model. In
Chapter5 we will discussotherwaysapartfor the interpretationof their semanticargumentsthat
adverbialscontribute to discoursecoherence.
156
![Page 174: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/174.jpg)
Chapter 4
Incorporating Adverbial Semanticsinto
DLTAG
4.1 Intr oduction
In Chapter2, we describedsimilaritiesanddifferencesbetweendiscoursetheoriesin termsof nec-
essarymodulesin acompletediscoursemodel.We introducedDLTAG asa theoryof intermediate-
level discoursestructurethat bridgesthe gap betweenclauseand discoursetheoriesby treating
discourse connectivesas predicatesand using the samesyntacticandsemanticmechanismsthat
build theclauseto build discourse.In Chapter3, wedistinguisheddiscourseandclausaladverbials
andshowedhow thepredicateargumentstructureandinterpretationof discourseadverbialscauses
themto functionasdiscourseconnectives.
In this chapter, we investigatehow the predicateargumentstructureandinterpretationof ad-
verbialscanbe incorporatedinto a syntax-semanticinterfacefor theDLTAG model. This chapter
will be exploratoryratherthanconclusive, asa completesyntax-semanticinterfaceincorporating
all aspectsof DLTAG andall discourseconnectives requiresa thesisin its own right. In Section
4.2,wediscusstheroleof thesyntax-semanticinterface,review LTAG, theclause-level modelupon
whichDLTAG is built, andcomparesyntax-semanticinterfacesthathave beenproposedfor LTAG.
In Section4.3,we review DLTAG, discussa syntax-semanticinterfacethathasbeenproposedfor
157
![Page 175: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/175.jpg)
a similar tree-baseddiscoursemodel,andexploreDLTAG extensionsof LTAG syntax-semanticin-
terfaces. In Section4.4, we discusshow the DLTAG annotationproject canbe usedto develop
anaphoraresolutionalgorithmsfor theanaphoricargumentsof discourseadverbialsandto train a
statisticalversionof theDLTAG parserto resolve ambiguousstructuralconnections.
4.2 Syntax-SemanticInterfacesat the SentenceLevel
4.2.1 The Roleof the Syntax-SemanticInterface
Naturallanguagecanbedefinedasasetof objects1. At thesentencelevel, for example,theseobjects
correspondto grammaticalandinterpretablesentences;at the discourselevel, they correspondto
grammaticalandinterpretablediscourseunits.
The goal of a languagegrammar(syntax)is to reproducethe structuresof all andonly these
objects. The grammarmust thereforecharacterizethe propertiesof this set (e.g. if it is finite or
infinite), definetheminimal units thatcomposeits members,anddefinerulesfor combiningthese
minimalunitsthatproduceall andonly thesemembers.In thesameway, thegoalof aformalmean-
ing representation(semantics)is to reproducetheinterpretationof all andonly theseobjects.Again
the propertiesof this setmustbe characterized,andthe minimal units that composeits elements
defined,alongwith rulesfor combiningthemthatproduceall andonly theseinterpretations.
In linguistics,theprincipleof compositionalityassertsthatthemeaningof awholeis a function
of the meaningof its parts. At the sentencelevel, for example,meaningfulsentencecomponents
correspondto syntacticsentenceconstituents.Thus,if in a grammarfor Englishwe have the rule
thata sentenceis minimally composedof a nounphrasefollowed by a verbphrase(e.g. S K NP
VP), then we might supposea one-to-onecorrespondencebetweensyntacticrules and semantic
rules,suchthat the interpretationof a sentenceis minimally composedof the interpretationof a
nounphrasecombinedwith theinterpretationof a verbphrase(e.g.S’ = f (NP’,VP’)). Thegoalof
thesyntax-semanticinterfaceis thento define,with respectto thesyntacticstructure,theextraction
from andassemblyof thecomponentsinvolvedin its interpretation.
1This discussionis derivedfrom [Gaz99].
158
![Page 176: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/176.jpg)
4.2.2 LTAG: LexicalizedTreeAdjoining Grammar
An LTAG(see[JVS99])is alexicalizedtree-adjoininggrammarwhichitself is anextensionof atree
adjoininggrammar(TAG) (see[Jos87]). Theobjectlanguageof anLTAG (or TAG) is asetof trees,
ratherthanstrings. Treesallow the underlyingstructureof a surfacestring to be represented,as
well asthestringitself. Thelanguagesgeneratedby (L)TAGsarewell known to be“mildly-context
sensitive”, properlycontainingthe context-free languagesandproperlycontainedby the indexed
languages.
An LTAG consistsof a finite setof elementarytreesandoperationsfor combiningthem. El-
ementarytreesareassociatedwith at leastonelexical item, calledthe anchor. Elementarytrees
representextendedprojectionsof the anchorandencodethe syntactic/semanticargumentsof the
anchor. An anchormaybeassociatedwith morethanonetree,calledatreefamily, eachtreereflects
thedifferentsyntacticconstructionsin whichthatanchorcanappear. For example,theverbeatmay
beeithertransitive or intransitive; eachof theseformsis givenacorrespondingtree.
Therearetwo typesof elementarytreesin anLTAG: initial trees,whichencodebasicpredicate-
argumentrelations,and auxiliary trees,which encodeoptional modificationand must containa
non-terminalnode(calledthe foot node)whoselabel matchesthe label of the root. Examplesof
elementaryLTAG treesareshown in Figure4.1. Thefinal treein this figureis anauxiliary tree,all
theothersareinitial trees.
SÍ Í ÍÎÎÎNP! Ë VPÏ ÏÐÐ
V
walks
NP� ËNP
N
John
NPÙ ÙÚÚD Ë N
dog
D
the
VPÖ Ö××ADV
often
VPÌFigure4.1: ElementaryLTAG Trees
Therearetwo structure-building operationsin anLTAG for creatingcomplex trees,calledde-
rived trees:substitution(indicatedby Ë ) andadjunction(indicatedby Ì ).Thesubstitutionoperationis restrictedto non-terminalnodesmarkedby Ë on thetreefrontier.
Substitutionconsistsof replacingthis nodewith the treebeingsubstituted.Only initial treesor
159
![Page 177: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/177.jpg)
treesderived from initial treescanbe substituted,andthe root nodeof the treebeingsubstituted
mustmatchthe label of the nodebeingreplaced. For example,the treeanchoredby the canbe
substitutedfor thenodelabeledáâË in thetreeanchoredby dog. This treecanthenbesubstituted
for theinternalargument(NP� ) in thetreeanchoredby walks, andthetreeanchoredby Johncanbe
substitutedfor theexternalargument(NP! ) in thetreeanchoredby walks. Theresultof thesetwo
substitionoperationsis thederivedtreein Figure4.2.
SÍ Í ÍÎÎÎNP
N
John
VP� � ����V
walks
NPÙ ÙÚÚD
the
N
dog
Figure4.2: LTAG DerivedTreeafterSubstitions
Theadjunctionoperationis restrictedto non-terminalnodesnotalreadymarkedfor substitution.
Adjunction consistsof building a new treefrom an auxiliary tree�
andany other tree � (initial,
auxiliary, or derived). In orderto combine�
and � by adjunction,the root nodeof�
mustmatch
the labelof thenode W in � to which it is to beadjoined. If this is thecase,the root nodeof�
is
identifiedwith W ; the subtreethat wasdominatedby W is attachedto the foot nodeof�
, andthe
restof thetreethatdominatedW now dominatestherootnodeof�
. For example,thetreeanchored
by oftencanadjoin to the VP nodeof the derived tree in Figure4.2, producingthe derived tree
correspondingto thesentenceJohnoftenwalksthedog, asshown in Figure4.3.
The treesin Figures4.2 and4.3 do not recordthe informationaboutwhich elementarytrees
werecombinedandwhich operationswereusedto combinethem.Thus,in additionto thederived
treethatrepresentstheresultsof combiningtreesto form complex trees,a -q.�o7+4ãqj`b�+'T�W treein LTAG
specifiesuniquelyhow a derivedtreewasconstructed.Nodesarelabeledaccordingto theelemen-
tary treeinvolved at that point in the derivation; the root of thederivation treecorrespondsto the
labelof theinitial treewhoseroot is S. In general,�B� labelsinitial treeswhoseanchoris ) (by defi-
160
![Page 178: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/178.jpg)
nition aninitial treeis substituted),and� � labelsauxiliary treeswhoseanchoris ) (by definitionan
auxiliary treeis adjoined). A treeaddressis alsoassociatedwith eachnodein thederivation tree
excepttheroot. This addressis theaddressof thenodein the PAj/op.�Wcb treeat which thesubstitution
or adjunctionoperationhasoccurred.Theaddressof therootnodein theparenttreeis 0, theaddress
of the ä "� child of thatroot is (k), and(p.q) is theaddressof the Q "� child of anodeP .
SÍ Í Í ÍÎÎÎÎNP
N
John
VPÍ Í ÍÎÎÎADV
often
VP� � ����V
walks
NPÙ ÙÚÚD
the
N
dog
Figure4.3: LTAG DerivedTreeAfter Adjunction
Thederivation treecorrespondingto thederived treein Figure4.3 is shown in Figure4.4. As
shown, the initial tree rooting the derivation is ��������� . ��������� substitutesinto ���$�%�&�� at address
(1) (NP! ), while� ���� "!#� adjoinsinto ��������� at address(2) (VP), and �B����F substitutesinto ���$�%�&�� at
address(2.2) (NP� ). �� "��! substitutesinto ������F at address(1) (D).���������� � � � � ���������������� (1)� ���� "!'� (2) ������F (2.2)�� "��! (1)
Figure4.4: LTAG DerivationTree
4.2.3 A Syntax-SemanticInterface for LTAG Derivation Trees
[JVS99] arguethatif theLTAG operationsof substitutionandadjunctionareviewedasattachments
of one tree to anothertree, then a syntacticsentencederivation consistsof an unorderedset of
attachments,andthecorrespondingsemanticscanbuilt monotonicallyasasemanticsof attachments
161
![Page 179: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/179.jpg)
anddescribedby a flat semanticrepresentation.For example,the semanticrepresentationof the
sentencecorrespondingto the structurein Figure 4.3 might be as in (4.1), where i1, i2 denote
individualsande1denotesanevent.
(4.1) john(i1) J walks(e1,i1, i2) J dog(i1) J often(e1)
[JVS99] notehowever, that the adjunctionoperationdoesnot preserve monotonicitywith re-
spectto theimmediatedominationrelation;theVP thatis immediatelydominatedby Simmediately
dominatesV in ��������� , but no longerimmediatelydominatesV afteradjunctionof �B���� "!'� .
Although under-specificationof the immediatedominancerelation would remove this non-
monotonicity, the tacit assumptionin many LTAG formalismsis ratherthat thenodeson thetrunk
of a tree(thepathfrom theroot to theanchor)arenot distinguishedsemantically; ([KJ99, Kal02,
JVS99]andreferencestherein)argue that usinga semanticsdefinedin termsof syntacticattach-
mentsremovestheneedto make useof syntacticunder-specificationif compositionalsemanticsis
definedwith respectto the derivation tree(Figure4.4), ratherthan the derived tree(Figure4.3).
Theseauthorsarguethat this is thenaturaltreeuponwhich compositionalsemanticsof sentences
shouldbebuilt, becausethepredicateargumentstructureof a lexical itemis representedonly in the
derivationtree(not in thederivedtree),andonly thederivationtreerecordsthedifferentelementary
treesinvolvedin thederivationanddistinguishesthesubstitutionof argumentsinto elementarytrees
from theoptionalmodificationof (adjunctionto) lexical itemsby otherlexical items2.
To build the compositionalsemanticsfrom the derivation tree, [JVS99] associatea tripartite
semanticrepresentationwith eachelementarytree.Thefirst partof therepresentationspecifiesthe
mainvariableof thepredication.Thesecondpart(innerbox) statesthepredication.Thethird part
(lowerboxes)associatesvariableswith argumentnodesin theelementarytrees.As anexample,the
semanticrepresentationsof (transitive) ���$�%�&�� and � ������� areshown in Figure4.5.
Thecompositionof theserepresentationsaftersubstitutionof � ������� in thesubjectpositionof���$�%�&�� is obtainedby unifying thevariable(x M ) correspondingto thesubjectnode3 in ��������� with
thevariable(x � ) which the representationcorrespondingto � ������� is j � T�k;b . After unification,the
2See[JVS99]for detailsconcerningdifferencesbetweenthedominationrelationsin derivationanddependency trees,andconstraintsonhow thederivationtreemustbetraversedwhenbuilding thecompositionalsemantics.
3This will beformalizedbelow by [Kal02] by statingpairsof variablesandcorrespondingnodeaddresses.
162
![Page 180: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/180.jpg)
secondparts(innerboxes)aremerged.Theresultingcompositionis still j � T�kAb theeventof walking
representedas . M . The semanticrepresentationafter composing���$�%�&�� and ��������� is shown in
Figure4.6.���$�%�&�� � �������about:eMwalk(eM , x M , x g ) named:x �
about:x �John(x� )
x1 x2
Figure4.5: SemanticRepresentationsof �������&�� and ���������Johnwalks
about:eMnamed:x Mwalk(eM , x M , x g )John(xM )
x2
Figure4.6: SemanticRepresentationsof Johnwalks
[JKR03, Kal02, KJ99] further formalize a syntax-semanticinterfacein which compositional
semanticsdependson theLTAG derivation tree. In orderto representscopeambiguitiesin quan-
tifier adjuncts,they employ a restricteduseof multi-componentTAGs,alongwith morecomplex
flat semanticrepresentationusing ideasfrom Minimal RecursionSemantics([CFS97])andHole
Semantics([CFS97,Bos95]), which consistsof threeparts: typedlambdaexpressions,scopecon-
straints,andargumentvariables.[Kal02] furtherarguesthatthederivationtreecanbeenrichedwith
additionallinks to supporta compositionalsemanticsthatcanrepresentall thedifferentiatedscope
orderingsof quantifieradjuncts,suchasthoseproducedby quantifierandPPadjunctsof NPs4.
We will discussdetailsof this approachbelow in referenceto DLTAG; in theremainderof this
sectionwe illustratehow the compositionalsemanticsof a simpleexamplecanbe built from the
LTAG derivation tree. [JKR03, Kal02, KJ99]’s semanticrepresentationsfor ���$�%�&�� , ��������� , � ���� "!'�4[FvG01] proposean alternative solutionto someof theseproblemsthatusesinformationfrom both the derivation
andthederivedLTAG tree.
163
![Page 181: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/181.jpg)
and ��������� areshown in Figure4.75. As shown, lambdaexpressions(formulas)maycontainpropo-
sitionallabels) � , holes V � (meta-variablesfor propositionlabels),aswell aspropositionalargument
variables( � (whosevaluesarepropositionallabels),andholevariables � (whosevaluesareholes).
Holesandlabelsareusedto generateunder-specifiedsemanticrepresentationsandallow for scope
ambiguities,whoseorderingis constrainedby thescopeconstraints.In �������&� , for example,thereis
a holeabove thepropositionlabel ) M which mayproducescopeambiguityconstrainedash MÆå l M .Quantifiersandadverbscanintroduceadditionalholesandlabels,asshown; scopedisambiguation
occurswhenthesesemanticrepresentationsarecombined,asdiscussedbelow. Argumentvariables
maybe of any variabletype,andmaybe linked to addressesin thesyntactictree. This linking is
explicitly representedasapair (e.g. Û x M ,(1)t , which indicatesthatx M is linkedto address(1)).���$�%�&�� � ������� �B������� ������ "!#�l M : walk(xM , x g )h Mæå l M———————————arg: Û x M ,(1)t , Û x g ,(2.2)t John(x� )
———–arg: –
Fido(xç )———–arg: –
l g : often(hg )g Mæå l g , hg å sM——————arg: g M , sM
Figure4.7: SemanticRepresentationsof ��������� , ��������� , ��������� , and� ���� "!#�
Whenthe derivation tree for the sentenceJohn oftenwalks Fido is built from its constituent
trees,thesemanticrepresentationof this sentencecanalsobebuilt. This representationis shown in
Figure4.8.
JohnoftenwalksFido
l M : walk(x� , x ç ), John(x� ), Fido(xç ), l g : often(hg )h Mæå l M , h Mæå l g , hg å l M——————————————————————arg: –
Figure4.8: SemanticRepresentationsof JohnoftenwalksFido
Combiningsemanticrepresentationsconsistsof building theunionof thesemanticrepresenta-
tionsof theelementarytreesinvolved in thederivationandassigningvaluesto argumentvariables.
Thederivationtreeindicateshow thesemanticrepresentationsareto becombinedsuchthattheirar-
5As [JKR03, Kal02, KJ99] do not discusstheir semanticrepresentationof definitedeterminers,we illustrate theirbasicapproachby replacingthedog from ourearlierexamplewith è�é"ê�ë .
164
![Page 182: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/182.jpg)
gumentvariablesgetvalues.Whenatreeis substituted,its valueis appliedto theargumentvariable
pairedwith thepositionatwhich it attaches.For example,thederivationtreein Figure4.3indicates
that thevalueof x M comesfrom the semanticrepresentationof � ������� , andthe valueof x g comes
from thesemanticrepresentationof �B���6��� .Whenatreeis adjoined,however, its argumentvariablesareaddedto therepresentationandare
assignedthevaluesat thepositionat which it attaches.For example,thederivation treein Figure
4.3 indicatesthatthevaluesof sM andg� comefrom thesemanticrepresentationof ���$�%�&� . Because( M is a propositionalargumentvariablewhosevaluesarepropositionallabels,it is assignedto ) M ,andbecause M is aholevariablewhosevaluesareholes,it is assignedto V M . Theseassignmentsare
reflectedin thescopeconstraintsin thecombinedsemanticrepresentation.
Scopedisambiguationconsistsof finding bijectionsfrom holesto labelsthat obey the scope
constraints.Accordingto thescopeconstraintsin Figure4.8,h M å l g andhg å l M . We alsoknow
thatl gxt hg , becausehg appearsinsidetheformulalabeledl g . We thereforeknow thatl gÆt l M , and
we know thath Mìuv l M , becauseif h M = l M thenl M å l g andwe alreadyknow thatl g t l M .Therefore,theonly possibledisambiguationof our holesis: h M =l g andhg = l M . This yieldsthe
embeddedsemanticrepresentationin (4.2).
(4.2)John(x3) J Fido(xç ) J walk(x� , xç ) J often(walk(x� , xç ))Notethatwe have presentedin this examplethemorecomplex semanticsinvolved in thetreat-
mentof scopeambiguitiesfor thepurposeof showing how scopeambiguitiesarehandledseman-
tically in this approach;below whenwe considera DLTAG versionof this approachwe will not
considerscopeambiguities,andwe will thusfollow [KJ99] in usingsimplifiedsemanticrepresen-
tationssuchasshown in Figure4.9.���$�%�&�� �B���� "!'�l M : walk(xM , x g )———————————arg: Û x M ,(1)t , Û x g ,(2.2)t l g : often(sM )
—————arg: sM
Figure4.9: SimplifiedSemanticRepresentationof ���$�%�&�� and� ���� "!'�
165
![Page 183: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/183.jpg)
4.2.4 A Syntax-SemanticInterface for LTAG Elementary Trees
[SBDP00]presentanextensionof theLTAG grammarin which thelexical entriesof motionverbs
arecraftedto make it aseasyaspossiblefor anaturallanguagegenerationsystem(SPUD,[SD97])
to selectthe verb that besthelpsits communicative goalsbe achieved. Briefly, SPUDgenerates
instructionsfor action in a concretedomain. SPUD’s desiredoutput is to mirror the naturally-
occurringaction instructionsin a selectedcorpus. SPUD’s input consistsof (1) a representation
of the context in which instructionis to be issued,(2) a set of communicative goalsdescribing
contentthattheinstructionshouldcontain,(3) adatabaseof factsdescribinggeneralizedindividuals
involved in the action (e.g. paths,placesand eventualities). When planninga sentence,SPUD
searchesthe derivationsof a true sentencethat areadmittedby the grammarfor onewhich best
achievesits communicative goalsin thecurrentcontext.
[SBDP00]constructa lexical entry, consistingof an elementarytree,a syntax-semanticinter-
face,anda semantics,for five motion verbs,basedon an analysisof their usein an instructional
corpus.The treesassociateeachanchor(verb)with its observed rangeandorderof complements
andmodifiersaccordingto their modificationtype6, by usingexhaustive nodehierarchiesin theel-
ementarytree,therebyallowing SPUDto generatetheseelementsin any orderwhile still producing
thecorrectsurfaceorder. As anexample,theelementarytreefor slide is shown in Figure4.10.
S� � ����NPÌ VP-PRPÌ
VP-DURÌVP-PTHÌÖ Ö××V
slide
NPËFigure4.10:TheElementaryTreefor slide
This treestructurerepresentstheobservedtype,order, andoptionalityin theinvestigatedcorpus
6see[KP02]) andChapter3 for discussionof thesemodificationtypes.
166
![Page 184: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/184.jpg)
of theargumentsandmodifiersof slide. As shown, all optionalelements,whetherthey aredeter-
minedto beoptionalargumentsor adjuncts,arerepresentedusingadjunctionso thatSPUDis not
forcedto anticipatehow thesentenceis to be completedbeforeselectingamongalternative trees.
An exampledemonstratingtheuseof slideandtheseelementsis shown in (4.3).
(4.3a) Slide thecover acrossthepole quickly to achieve a tight seal.T � {`.Ci8b PAj/b�V -pkAo7j/b�+'T�W P;k;o8PAT>(�.(PTH) (DUR) (PRP)
SPUDusesanontologicallypromiscuoussemantics[Hob85] suchthateachlexical entryused
in thederivationof anutterancecontributesaconstraintto its overallsemantics;thesyntax-semantic
interfacedetermineswhichof theconstraintscontributedby anentrydescribethesamegeneralized
individuals. For example,given the phraseslide the sleeve quickly, the syntax-semanticinterface
guaranteesthattheevent . describedby slide is identifiedwith anevent .*í thatis quick. To express
thesemanticrelationshipsbetweenmultiple entriesin a derivation, [SBDP00] associateeachnode
in theelementarytreewith the individualsthat thenodedescribes.Whenonetreecombineswith
anotherby substitutionor adjunction,anodein onetreeis identifiedwith anodein anothertreeand
thecorrespondingentitiesareunified. Theindividualsassociatedwith eachnodein theelementary
treein Figure4.10areshown in Figure4.11.
The collectionof individuals associatedwith the nodesof a verb treearecalled its semantic
arguments. [SBDP00]’s notion of a semanticargumentis clearly distinguishedfrom the LTAG
notion of an syntacticargument. Eachsyntacticargumentcorrespondsto onesemanticargument
(or more),sincethe syntacticargumentpositionis a nodein the treeandis associatedwith some
semanticargument(s).However, semanticargumentsneednot be associatedwith syntacticargu-
mentpositions.For example,thereis no nodein thetreeinto which theeventuality . describedby
slidesubstitutes,but eventualitiesareneverthelesstreatedasa semanticargumentof boththeverb
andof eventmodifierssuchasquickly, asin [Dav67]. Moreover, optionalconstituentsspecifying
paths,durations,or purposesareusuallytreatedsyntacticallyasmodifiers,usingadjunction.Here,
althoughall optionality is treatedvia syntacticadjunction,theseadjunctionsitesmayeitherbeas-
sociatedwith referencesto only theoveralleventualityargumentof theverb,makingtheseadjuncts
167
![Page 185: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/185.jpg)
semanticadjunctsaswell, or with referencesto additionalsemanticarguments(e.g.paths), making
themsemanticarguments.[SBDP00,4] notehowever that it is a substantive questionfor grammar
designwhich optionalconstituentsshouldbe treatedasspecifyingadditionalsemanticarguments
for a given verb entry; they make useof the testsdescribedin Chapter3 to distinguishsemantic
argumentsfrom semanticadjuncts(e.g.thedo so test,theextraction test,thepresuppositiontest).
S K î event: eïð ð ð ð ð ð ð ð ð ðññññññññññNPÌÈK î ind: agentï VP-PRPÌòK î event: eï
VP-DURÌóK î event: eïVP-PTHÌ�K }~~� event: e
path:p
changed:obj
�&���� � � � � � ��������V K }~~� event: e
path:p
changed:obj
� ���slide
NPËôK î ind: objïFigure4.11:TheSyntax-SemanticInterfacefor (*),+'-/.
[SBDP00]furtherspecifythesemanticrepresentationassociatedwith eachverbentry, in terms
of an assertionand a presuppositionaboutthe individuals referencedin the tree. The semantic
representationassociatedwith theverbentryfor slide is shown in (4.4).
(4.4a)Presupposition:located-at-start(obj, P ), along-surface(P )
(4.4b) Assertion:caused-motion( . , agent, obj, P )
In SPUD,theassertioncontributesnew relationshipsamonggeneralizedindividuals.For exam-
ple,slideassertsthatanagentcausesanobjectto move alonga path.Thepresuppositionindicates
backgroundknowledgeaboutadditionalrelationshipsbetweengeneralizedindividualsinvolved in
theassertion7. For example,aslidingeventpresupposesthatthepathalongwhichtheobjecttravels
7We discusspresuppositionin detail in Chapter5.
168
![Page 186: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/186.jpg)
hasan origin, andpresupposesthat this path involves a surfacethat remainsin contactwith the
objectduringthesliding.
4.2.5 Comparison of Approaches
Althoughboth[JKR03, Kal02, KJ99, JVS99]and[SBDP00]proposeasemanticsandandasyntax-
semanticinterfacelinking it to the LTAG grammar, the two approachesdiffer in a numberof su-
perficial ways. First, [SBDP00]postulatesa differentsetof elementarytrees. Eachof their trees
fully specifies,ashierchicalnodes,all observedsyntacticargumentsandmodifiersthatappearwith
thecorrespondingverbin a corpus,regardlessof whetherthey aredeterminedto functionsemantic
argumentsor adjuncts.In [JKR03,Kal02, KJ99, JVS99]’s approach,only syntacticargumentsare
representedin their elementarytrees.
Second,[SBDP00] specifiesin theelementarytreethesemanticargumentscontributedby both
argumentandmodifiernodesto thesemanticrepresentation,while [JKR03, Kal02, KJ99, JVS99]
specifyonly in thesemanticrepresentationassociatedwith theentireelementarytreethesemantic
contribution of argumentnodes.
Third, [JKR03, Kal02, KJ99, JVS99] argue that thereis no semanticdistinctionbetweenthe
nodeson thetrunkof thesyntactictree(e.g.S-VP-VP-V),while [SBDP00] explicitly distinguishes
thesemanticcontribution of eachnode.
Fourth,[SBDP00]don’t specifywhether, duringsubstitutionor adjunction,theidentificationof
theentitiessuppliedby acomplementor modifierwith theentitiesassociatedwith thecorresponding
nodein theverbelementarytreeis madebasedon thederived or derivation tree. [JKR03, Kal02,
KJ99, JVS99]arguethat thederivation treeis theappropriateplaceto specifythesyntax-semantic
interfacebecausethederivedtreeis syntacticallynon-monotonicandonly thederivationtreerecords
thepredicateargumentstructureandoperationinvolvedin constructingthesyntacticrepresentation.
Although [SBDP00] do not provide detailson how the interpretationof a sentenceis con-
structed,[SBDP00]and[JKR03, Kal02, KJ99, JVS99]’sapproachesarepotentiallycomplementary.
In particular, in [SBDP00]’sapproach,eachnodehasauniqueaddress.Thereforetheidentification
of thespecifiedsemanticargumentsat eachnodewith thesemanticargumentsof treesadjoinedor
169
![Page 187: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/187.jpg)
substitutedat thosenodescanbebasedon thederivationtree.
Themostsignificantdifferencebetweenthetwo approachesis [SBDP00]’s pre-specificationof
all possibleargumentsandmodifiersin theelementarytree.Thepurposeof this is to provideSPUD
with all theinformationit mayneedto exploit in a computationallyefficient way, whengenerating
anutteranceaccordingto its conversationalgoals.GiventhatSPUDappliesin alimited domainand
its outputis meantto mirror afinite corpus,thisapproachmaybemostcomputationallyefficient in
thisdomain.It is notclearhowever, thatthisapproachis bestwhenconsideringgenerationor inter-
pretationin unlimiteddomains.For example,in Chapter3, a wide rangeof modifiersdrawn from
theWSJandBrown werediscussed,someof whichcouldbecategorizedinto multiplemodification
types. It remainsanopenquestionof whetherit is possibleto createa modificationclassification
which is at oncecompactenoughto be incorporatedinto theelementarytreesof all verbs,andat
thesametime accuratelyandcomprehensively coverstheinterpretationsof (andany idiosyncratic
semanticargumentsspecifiedby) all modifiers.
We endthis sectionwith thecommentthatLTAG is not theonly syntacticgrammarfor natural
language;CombinatoryCategorial Grammar(CCG)[Ste96] is onealternative which encodesbuth
thesyntacticandsemanticpropertiesof wordsin thelexicon. For example,thetransitive verb like
might have thelexical entryin (4.5).
(4.5) lik e=syn: Sõ NP/NP
sem: ß x ß y.like(y,x)
Briefly, in CCG,/ refersto a rightward-lookingcategory and õ to a leftward-lookingcategory.
Categoriescombineusingrulesof functionapplication. (4.5) statesthat the syntacticcategory of
lik e is afunctionthatrequiresits syntacticargument,anNP, onits right. A functionapplicationrule
is applied,suchthat the NP on the right is identifiedandthe correspondingsemanticargumentis
simultaneouslyboundto theoutervariable� . A new functionis producedthatrequiresits syntactic
argument,againan NP, on its left. Anotherfunctionapplicationrule is applied,suchthat the NP
on the left is identifiedandthe correspondingsemanticargumentis simultaneouslyboundto the
variable� . Theresultis anSwith semanticslike( � , � ), where� and � havebeenboundasdescribed.
Onereasonfor usingCCG is that it removesthe needfor a syntax-semanticinterfacespecifying
170
![Page 188: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/188.jpg)
how a semanticsanda syntaxarerelated.See[Ste96, JVS99]for a discussionof similaritiesand
differencesbetweenthetwo grammars.
4.2.6 Summary
In this sectionwe have overviewed the LTAG grammar, andhave presentedtwo syntax-semantic
interfacesthathavebeenproposedfor LTAG. In thenext sectionwewill focusonthedetailsof DL-
TAG, whichbuildsdiscoursegrammardirectlyon topof theLTAG clausegrammar, andinvestigate
how syntax-semanticinterfacesfor suchLTAG-baseddiscoursegrammerscanbedefined.
4.3 Syntax-SemanticInterfacesat the DiscourseLevel
4.3.1 DLTAG: LexicalizedTreeAdjoining Grammar for Discourse
Like many of the other discoursemodelsdiscussedin Chapter2, DLTAG [FMP�
01, CFM�
02,
WJSK03,WKJ99, WJSK99, WJ98] arguesthat discoursecanbe modeledin termsof syntaxand
semantics,but unlikeothermodels,DLTAG definesdiscoursestructureandmeaningin termsof the
samemechanismsthatarealreadyusedat thesentencelevel, andbuilds them,furthermore,directly
ontopof theclause.As [WJSK03, 23]note,thenotionthatdiscourserelatesto syntaxandsemantics
in a completelydifferentway thanthesentenceseemsstrangewhenwe considerexamplessuchas
(4.6),whereanentirediscourseis containedwithin a relative clause,exhibiting thesamecohesive
andargumentative connectionswhicharecharacteristicof otherdiscourses.
(4.6) Any farmerwho hasbeatena donkey andgonehomeregrettingit andhasthenreturned
andapologisedto thebeast,deservesforgiveness.
In DLTAG, discourseconnectivesaretreatedakin to verbsat theclauselevel. As discussedin
Section4.2,verbsat theclauselevel aregenerallyviewedaspredicatesthat take entity interpreta-
tions andsupplyrelationsbetweenthemto form a sentenceinterpretation.In DLTAG, discourse
connectivesarealsopredicatesthat take entity interpretationsandsupplya relationbetweenthem
to form interpretationsof larger discourseunits. Thesetof discourseconnectives in DLTAG cur-
rently includesthesubordinatingandcoordinatingconjunctions,punctuationat clauseboundaries,
171
![Page 189: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/189.jpg)
anddiscourseadverbials,As we saw in Chapter3, theentity interpretationsthey relateareabstract
objects(AOs),which may comefrom non-NPconstituentswithin clauses,clausesthemselves,or
discourseunits that arecomposedfrom both clausesanddiscourseconnectives, within or across
sentenceboundaries.Wewill thususeD 5 to representthesyntacticargumentsof all discoursecon-
nectivesandtheunit thatresults(ratherthanS),bothto indicatethattheseunitsarebeinganalysed
from thepointof view of discourse,andbecausetheclause-level syntacticconsituentcorresponding
to theseunitscanvary.
DLTAG currently builds discourseusing the structuresand structure-building operationsof
(LTAG)[JVS99], which itself is widely usedto model the syntaxof sentences.As in LTAG, in
DLTAG eachelementarytree is anchoredby at leastone lexical item or correspondingfeature
structure8. Also as in LTAG, thereare two kinds of elementarytrees: initial treesthat represent
atomicunits andlocalizepredicateargumentdependencies,andauxiliary treesthat representop-
tional modification.
In DLTAG, two initial treesareproposedin the treefamily that representssubordinatingcon-
junctions,exemplified in Figure 4.12. Two treesare proposedbecauseof the syntacticalterna-
tion that subordinatingconjunctionsallow with repectto their positionrelative to their arguments
[QGLS85],asshown in (4.7).
(4.7a)Johnis hardto find, althoughheis generous.
(4.7b) Althoughheis generous,Johnis hardto find.
D 5� � � � ������D 5 Ë although D 5 Ë D 5� � � �ö ö����
Although D 5 Ë D 5 ËFigure4.12:DLTAG Initial Treesfor SubordinatingConjunctions
In LTAG, subordinatedclausesaretreatedasadjunctsbecausethey arenotpartof theextended
projections(e.g. argumentstructure)of theverbof themainclause.In DLTAG, however, it is the
extendedprojectionsof thediscourseconnective, not theverb,thatarebeingmodeled;subordinat-
8See[WJ98] for a discussionof reasonsfor treatinglexical anchorsas featurestructuresthat may or may not belexicalized.
172
![Page 190: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/190.jpg)
ing andcoordinatingconjunctionsrelatetwo clausalinterpretationto form a larger discourseunit
andthusarerepresentedastaking two substitutedarguments.Subordinatingconjuctionsarethus
modeledwith initial trees;asshown in (4.8), the local dependenciesbetweentheir arguments(4.8
a) canbe stretchedlong-distancevia adjunctionof an additionalclause(4.8 b), asis alsotrue of
localdependenciesat theclauselevel (e.g.Apples,Bill saysJohnmaylike.).
(4.8a)AlthoughJohnis generous,he’s hardto find.
(4.8 b) Although Johnis generous–forexample,he givesmoney to anyonewho askshim for
it-he’s hardto find.
In DLTAG,two differenttypesof auxiliarytreesareproposed.Thefirst typeis usedto represent
simplecoordinationandanemptyconnective 0 , asexemplifiedin Figure4.13.
D 5Í Í ÍÎÎÎD 5 Ì and D 5 Ë D 5� � ����
D 5 Ì 0 D 5 ËFigure4.13:DLTAG Auxiliary Treefor andand 0
While both argumentsin thesetreescomestructurally, adjunction to a discourseunit in the
prior discourse(ratherthansubstitution)representsthe fact that and, or, 0 convey a continuation
(or optionalmodification)of somethingin theprior discourse.In otherwords,simplecoordination
provides further descriptionof a situationor of one or more entities(objects,events,situations,
states,etc.)within thesituation[WJSK03]. This is akin to thenotionof elaboration, asexemplified
in (4.9a); it alsoaccountsfor caseswhereacoordinatingconjunctionis usedto connecttwo clauses
thatsupplythesamerelationvia astructuralconnective to theprior discourse,asexemplifiedin (4.9
b), wherebothdisjunctsconvey analternative pointat whichJohnwill quit his job.
(4.9a)Johnwentto thezoo[and/.] H/hetookhis cell phonewith him.
(4.9b) Johnwill quit his job whenhewins thelottery [and/or] hemarriesa rich woman.
Thecoordinatingconjunctionsso,but convey morethansimplecontinuation,however; so, for
example,conveys a result relation in (4.10). Theseconnectives are thus representedwith initial
173
![Page 191: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/191.jpg)
trees9.
(4.10)You didn’t eatyourspinachsoyouwon’t getdessert.
Thesecondtypeof auxiliary treeproposedin DLTAG representsdiscourseadverbials;asshown
in Figure4.14,therearetwo treesin thetreefamily representingdiscourseadverbialsdueto their
ability to appearS-initially andS-finally. Notehowever that,asdiscussedin Chapter3, discourse
adverbials, like all adverbials,can appearin a variety of other positions. Currently in DLTAG,
discourseadverbialsareextractedfrom S-internalpositionsandthemodeledusingtheS-initial tree
with a traceleft in their originalposition(see[FMP�
01] for details).
D 5÷ ÷øøD 5 Ì then
D 5÷ ÷øøthen D 5 Ì
Figure4.14:DLTAG Auxiliary Treesfor DiscourseAdverbials
TheseDLTAG treesarestructurallyidenticalto LTAG treesfor S-modifyingadverbials(except
for thelabelof their root node);thedifferencelies in thefact that in theDLTAG (discourse)gram-
marall discourseunitsarestructurallyrelatedto theprecedingdiscourse.A discourseadverbial is
viewedasanoptionalmodificationof theincomingunit, which suppliesanadditionalsemanticre-
lationoverandabove thesemanticrelationsuppliedby thestructuralconnection;thustheargument
a discourseadverbial modifiesis representedasadjunction. Only the modifiedargumentcomes
structurally, however. Theotherargumentinvolved in thesemanticrelationsuppliedby theadver-
bial mustbe resolved anaphorically. In orderto connecta discourseunit modifiedby a discourse
adverbial to theprior discourse,therefore,a structuralconnective mustbe employed (e.g. 0 , and,
etc.),whichsuppliesits own semanticrelation.Moreover, theremaybeadditionalinferredrelations
betweentheincomingunit andtheprior discourseover andabove boththerelationsuppliedby the
structuralconnectionandthe relationsuppliedby any discourseadverbials. For example,in DL-
TAG’sview, 0 andasa resultin (4.11)eachsupplyasemanticrelationbetweentheinterpretationsof
Johncamehomelate andMary left him; in addition,a temporalrelationbetweenthesetwo clauses
9This is notexplicitly statedfor but; however, by definitionit mustbethecase.Thesameargumentmayalsohold forcertainusesof and,or; see[WJSK03],footnote17, for discussion.
174
![Page 192: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/192.jpg)
is inferred10.
(4.11)Johncamehomelate.As a result,Mary left him.
As discussedin Chapters2 and3, behavioral evidenceis presentedin [WJSK03]to supportthe
theoreticalview that discourseadverbialstake their prior argumentanaphorically. This evidence
includestherangeof waysthisargumentcancomefrom theprior discourse.For example,although
discourseconnectives aregenerallytaken assignallingdiscourserelationsbetweenadjacentdis-
courseunits,just ascanNP anaphora,discourseadverbialscanalsotake their prior argumentfrom
intra-sententialand implicit material. In (4.12) [WJSK03, 7], embeddedneverthelessrelatesthe
interpretationof the matrix clauseto the interpretationof the relative clause. This option is not
availableto subordinatingandcoordinatingconjunctionsbecausetheir argumentsareconstrained
to beadjacentdiscourseunitsof like syntactictype.
(4.12)Many peoplewho have developednetwork softwarehave neverthelessnever gottenvery
rich. (i.e. despitehavingdevelopednetworksoftware)
In (4.13)[WJSK03, 7], otherwisecanaccesstheinferredconditionof if thelight is notred. This
materialis not availableto structuralconnectives;or canonly accesstheconsequentclause(stop)
or thesentenceasa whole.
(4.13a) If thelight is red,stop.Otherwisegostraighton.
(4.13b) If thelight is red,stop,or gostraighton.
Wesaw furtherevidencein Chapter3, wherewe consideredtherangeof semanticmechanisms
underlyingthepredicateargumentstructureandinterpretationof S-modifyingadverbials.We saw
that we could distinguishdiscourseadverbialsandclausaladverbialsaccordingto whetheror not
their interpretationdependedon an abstractobject in the prior discourse.We saw that discourse
adverbialscontainsemanticargumentsinstantiatedasexplicit discoursedeicticreferenceto abstract
objects,demonstrative NP referenceto abstractobjects,comparative abstractobjects,relational
abstractobjects,etc. Becauseall of theseargumentsareanaphoricto abstractobjectsin theprior
discourse,thediscourseadverbialscontainingthemfunctionsemanticallyasdiscourseconnectives.
10SeeChapter2 for anexampleof how this inferenceis modeled(in [LA93]’ s discoursemodel).
175
![Page 193: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/193.jpg)
Moreover, theanaphoricargumentinvolvedin therelationsuppliedby anadverbialmayor may
not resolve to theprior argumentinvolved in thestructuralrelation.In fact,a propertyof structural
connectives is that they do not allow crossingof predicate-argumentdependencies.For example,
while (4.14)[WJSK03, 5] is interpretableasanembeddedif S1,S2constructionwithin analthough
S1’,S2’construction,crossingthesedependenciesasin (4.15)[WJSK03, 5] is eitheruninterpretable
or at leastyieldsadifferentinterpretation;thedependenciesin theoriginal constructionsarelost.
(4.14)
a. AlthoughJohnis very generous-
b. if youneedsomemoney,
c. youonly have to askhim for it -
d. he’s very hardto find.
(4.15)
a. AlthoughJohnis very generous-
b. if youneedsomemoney -
d. he’s very hardto find-
c. youonly have to askhim for it.
It appearshowever thatdiscourseadverbialsdoallow crossingdependencies,asshown in (4.16)
[WJSK03, 6]. For thenin (d) to getits first argumentfrom (b), it mustcrossthestructuralconnection
betweenthe clausesin (c) and(d) that arerelatedby � .�i�j/k$(�. . Of course,as[WJSK03, 6] note,
anaphorafrequentlyshow crossingdependencies(e.g.JohnM told Mikeg heM wouldmeethimg later.
[WJSK03] show thatmodellingthesediscourserelationsstructurallywouldcreateadirectedacyclic
graph,which goesbeyondthecomputationalpower of LTAG and,moreoever, createsa completely
unconstrainedmodelof discoursestructure.
(4.16)
a. JohnlovesBarolo.
b. Soheorderedthreecasesof the’97.
c. But hehadto canceltheorder
d. becausethenhediscoveredhewasbroke.
It remainsto beshown however whetheror not all discourseadverbialsallow crossingdepen-
dencies;the fact that the felicity of constructedexamplescan be difficult to determinehas led
[FMP�
01] to outline a moreempirically-basedapproachto modelingdiscourseconnectives. As
176
![Page 194: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/194.jpg)
their goal is to build the mostcomputationallyefficient discourseparserpossible,they arguethat
predicateargumentdependenciesshouldbedefinedstructurallywheneverpossible,regardlessof the
compositionalsemanticsof thepredicate.In otherwords,thedecisionto treata discourseconnec-
tiveanaphoricallywouldbebasedentirelyonwhethercorpusannotationindicatesit to benecessary
to avoid modelingcrossingdependenciesstructurally, ratherthanon their compositionalsemantics
or on constructedexamples. This approachmay help distinguishwhencompositionalsemantics
determineshow anadverbialretrievesits prior argumentandwhenit doesnot.
Certaindiscourseadverbials,however, arealreadyrepresentedin DLTAG astakingbothargu-
mentsstructurally. In particular, DLTAGdistinguishesparallel constructions,conveying disjunction
(“either...or”), contrast (“on theonehand...ontheotherhand”),addition“not only...but also”), and
concession(“admittedly...but”). Becauseof the interpretedinter-dependency of thediscoursecon-
nectivesin theseconstructions,they aremodeledwith initial trees,asin Figure4.15.
D 5� � � � � � ��������D 5Í Í ÍÎÎÎ
Ontheonehand D 5 Ë D 5Í Í Í ÍÎÎÎÎOn theotherhand D 5 Ë
Figure4.15:DLTAG Initial Treefor AdverbialConstructions
However, thesediscourseadverbialsdo not alwaysappearin theseparallelconstructions.The
majority of them,morefrequentlythesecondin thepair ([WJSK03]), canalsoappearalone,asin
(4.17),in whichcasethediscourseadverbialtakesthefirst auxiliary treein Figure4.14.
(4.17)Mike likesicecream.On theotherhand,hehatesmilk.
We have alreadydiscussedhow the two structurebuilding operationsin (D)LTAG work, we
now illustratewith theexamplein (4.18)theDLTAG treesthey produce.Wewill addressadditional
examplesin subsequentsections.
(4.18)On theonehand, I noticedthesolitudein New Hampshire,and thenI hopedwe could
stay. On theotherhand,whenI noticedthelackof multi-culturalism,I hopedwe would leave.
Werepresentclausesusingthesymbolfor initial treessubscriptedby thenameof themainverb
177
![Page 195: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/195.jpg)
(e.g. �B�@����! ). In fact,oneof thebenefitsof DLTAG is that it parsesdiscourseon top of theclause
level parse;thuseachatomicclauseis itself a complex tree11. Thederivedtreefor (4.18)is shown
in Figure4.16.
D 5ð ð ð ð ð ð ð ð ð ð ð ðññññññññññññD 5� � � � � �������
On theonehand D 5� � � � �ùù������ ���� ���34! and D 5Ö Ö××then � ' "��9
D 5� � � � � �������On theotherhand D 5� � � �����
when � �7�� ���34! �B�&!���=�!Figure4.16:DLTAG DerivedTreefor Example(4.18)
The derivation tree for our exampleis shown in Figure4.17. We representinitial treeswith
discourseconnective anchorsase.g. ������� (= on theone/otherhand), auxiliary treeswith discourse
connectiveanchorsase.g.� "��!#� , andsubstitutionandadjunctionaddressesarerepresentedasabove
(i.e. with respectto theparenttree(e.g.(2.2)). Thereadershouldreferto theabove figuresto view
theelementarytreesthatcorrespondto eachdiscourseconnective.�B������ � � � ������� �7�� ��63'! (1.2)� ���7� (0)� 4 "��9 (3)� "��!#� (0)
���$�C!'� (2.2)Í Í ÍÎÎÎ� ���� ���34! (2) �B�&!���=%! (3)
Figure4.17:DLTAG DerivationTreefor Example(4.18)
11See[FMPÑ 01] for detailsof theDLTAG parser.
178
![Page 196: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/196.jpg)
4.3.2 Syntax-SemanticInterfaces for DerivedTrees
In Chapter2 webriefly discussedtwo similarTAG-basedapproachesto incrementaldiscoursestruc-
ture, one([Web91]) which outlines“right frontier” constraintson discoursedeixis reference,and
another((LDM - see[Pol96, vdB96]) which outlineshow the“right frontier” andthediscoursere-
lation betweendiscourseunitsaccountfor constraintson theantecedentsof NP anaphorain local
discoursespans.Bothof theseapproachesemploy thesametwo operations([Gar97b]) for combin-
ing incomingelementarydiscourseunits(clauses),althoughtheir terminologyvaries,andbothusea
similarsyntaxsemanticinterfacewith respectto thederivedtree.Theoperations,calledattachment
andadjunctionin [Web91], andtheireffecton thesemanticinformationateachnode,areillustrated
againrespectively in Figure4.18.
Figure4.18: Illustrationof [Web91]’sAttachmentandAdjunctionOperations
In thefirst treefor theattachmentoperation,two nodeshave alreadycombined(by rootadjunc-
tion), andtheir semanticinformationhasbeencombinedin theparentnode,e.g. “(1,2)”. Attach-
mentof a third nodeto thisparentnodecreatesthesecondtreeandcausesthesemanticinformation
“(3)” associatedwith this incomingnodeto be incorporatedinto the semanticinformationof the
parentnodeto which it attachesto yield “(1,2,3)”. Roughly, attachment,e.g. inclusionin an ex-
isting discoursesegment,correspondsin bothapproachesto thesemanticlist relation.A discourse
correspondingto theresultof attachmentis shown in (4.19).
(4.19)I like summerandI like winterandI like autumn.
In thefirst treefor theadjunctionoperation,againtwo nodeshave alreadycombined(by root
adjunction),and their semanticinformationhasbeencombinedin the parentnode,e.g. “(1,2)”.
Adjunctionof a third nodeto this parentnode(root) createsa new discoursesegmentnode(whose
179
![Page 197: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/197.jpg)
daughtersaretheoriginal parentandthe incomingnode)asshown in thesecondtree,andcauses
thesemanticinformationof bothchildrento beassociatedwith this new nodeto yield “((1,2),3)”.
Roughly, adjunction,e.g. creationof an embeddeddiscoursesegment,correspondsin both ap-
proachesto beginning a list relation,begining a temporalprogression,a causalrelation, etc. A
discoursecorrespondingtheresultof adjunctionis shown in (4.20),wherethefirst two clauseswill
beembeddedunderacausenode.
(4.20)Johnjoined thesoccerteamandMike joined the football teambecausethey wantedto
impresstheir fathers.
In bothapproaches,theseoperationsareconstrainedto applyto nodeson theright frontier (the
smallestsetof nodescontainingthe root suchthat whenever a nodeis on the right frontier, so is
its rightmostchild[Web91]). Wheretheapproachesdiffer is with respectto upwardpercolationof
semanticinformationasaresultof adjunctionatnodesotherthantheroot. [Web91] doesnotprovide
formal detailsconcerningthe syntaxsemanticinterfaceor explicitly addressthe issueof upward
percolation,however her examplesof adjunctionat a leaf show upward percolationof semantic
informationafteradjunctionat a leaf,asshown in figure. In this tree,afteradjunctionof i to � , not
only doestheir new parentnodecontainthe information(b,c), but this informationhaspercolated
up to therootnode,replacing(a,b)in thefirst treewith (a,(b,c))in thesecondtree.
Figure4.19:Webber’s AdjunctionataLeaf
In contrast,althoughLDM explictly defineshow theadjunctionoperationcombinestheseman-
ticsateachchild nodein thenew parentnode,they donotaddresstheneedfor upwardpercolation.
[Gar97b] arguesthat this lack of upward percolationis a problemfor LDM, becausethereis no
obviousway to readsemanticsoff treesandthereis no way to retrieve theavailableantecedentsof
180
![Page 198: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/198.jpg)
discoursedeixisoff theright frontier of thetree,becausethenecessarysemanticinformationis not
madeavailablethere.Gardentillustratesthisusing[Web91]’sexample,first presentedin Chapter2
andrepeatedin (2.41)-(2.42).As Webbernotes,thediscoursedeicticreferencein (2.42)is ambigu-
ous;it canreferto any of thenodeson theright frontier of the(derived)tree:(thenodesassociated
with) clause(2.41e),clauses(2.41d)-(2.41e),clauses(2.41c)-(2.41e),clauses(2.41a)-(2.41e).
(2.41a)It’s alwaysbeenpresumedthat
(2.41b)whentheglaciersreceded
(2.41c)theareagot very hot.
(2.41d)TheFolsummencouldn’t adapt,and
(2.41e)they diedout.
(2.42)That’s what’s supposedto have happened.It’s thetextbookdogma.But it’s wrong.
UnderLDM’ s approach,the treefor (2.41) is shown in Figure4.20. Neitherthe root nor the
right frontier describesthesemanticsof this discoursecorrectly. For example,whatwe interpretas
presumedis not only � , but all of � - . , andwhatwe interpretwhenrelatingis not � and i , but � andi - . . Moreover, resolutionof that in (2.42)to � - . will incorrectlyyield asa semanticsfor b�VXj/b the
propositiondenotedby when(b,c)12.
presume(a,b)ú úûûa when(b,c)ú úûû
b cause(c,d)ú úûûc cause(d,e)� ���
d e
Figure4.20:DerivedTreefor Example(2.41)
[Gar97b] proposesDTAG,agrammarthatusesmodifiedversionsof thesyntactictree-construction
operationsand featurestructuresin feature-basedTAG (FTAG) (see[Gro99, Shi86]) alongwith
LDM’ ssemanticsandlexicon to solve LDM’ sproblemsarisingfrom lack of upwardpercolation.
12Lack of percolationis nota problemfor rootadjunctionbecauseit retainsthesemanticinformationof its children.
181
![Page 199: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/199.jpg)
FTAG is identical to LTAG with respectto its structurebuilding operations.However FTAG
associateseachtreenode W , exceptfor substitutionnodes,with a top ( b � ) andbottom( � � ) feature
structure.Top featurescapturethe relationof W to its super-treeandbottomfeaturescapturethe
relationof W to its sub-tree.Substitutionnodeshave only top featuressincethetreesubstitutingin
logically carriesthebottomfeatures[Gro99, 8]. As shown in Figure4.21,aftersubstitution,thetop
featuresof thesubstitionnodeunify with the top featuresof thesubstitutednode,andthebottom
featuresareprovidedby thesubstitutednode.As definedin [JVS99], unificationcreatedtheunion
(U) of thespecifiedfeaturesandthereplacementof any featurevariableswith featuresthatcontain
valuesfor thesevariables.Onceprocessingatanodeis complete,its topandbottomfeaturesunify.
Y� b 9 g� 9 g �ü üýý + Xú úûû
Z YË [ b 9 M ] K XÍ Í Í ÍÎÎÎÎZ Y
� b 9 M U b 9 g� 9 g �ü üýýFigure4.21:Substitutionin FTAG
As exemplifiedin Figure4.22,after adjunction,the nodein X beingadjoinedinto splits, and
its top featuresunify with the top featuresof the root adjoiningnode,while its bottomfeatures
unify with thebottomfeaturesof thefoot adjoiningnode.Two setsof featuresallow thesemantic
relationshipsbetweenX andits sub-treeandsuper-treeto be maintainedafter adjunction.Again,
onceprocessingatanodeis complete,its topandbottomfeaturesareunified.
Xú ú úûûûA Y
� b 9 M� 9 M �þ þÿÿ+ Y
� b 9 g� 9 g �� � ����B YÌ � b 9 �� 9 � �
K XÍ Í ÍÎÎÎA Y
� b 9 M U b 9 g� 9 g �Í Í Í ÍÎÎÎÎB Y
� b 9 �� 9 M U � 9 ���þ þÿÿFigure4.22:Adjunctionin FTAG
182
![Page 200: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/200.jpg)
In [Gro99]’sdescription,featurescapturehow predicatesconstrainor assignsemanticattributes
suchascase,agreement,numberetc, of the lexical items they take asarguments. For example,
prepositionsassignaccusative caseto their substitutedinternalNP arguments.In a PPelementary
tree,this assignmentis explicitly statedby an“assigncasefeature”[Gro99, 24], becauseNPsare
givena default casefeaturevalue.Without this feature,feature-unificationaftersubstitutionwould
notalterthedefault valueof thecasefeaturesof asubstitutedNP.
DTAG usesfeaturestructuresandoperationsto allow upwardpercolationof semanticinforma-
tion. DTAG contains1) asetof “discoursebasic”(B) trees,whicharesingle-nodetreesimplement-
ing the elementarydiscourseunits (DCUs) andtheir typedfeaturestructuresin LDM, 2) a setof
“discourserule” (R) trees,eachof which implementsa discoursegrammarrule of LDM, and3)
operationsfor combiningthem. Eachnodeof a DTAG treeis associatedwith two setsof feature
structuresmodeledafterthosein FTAG.
RecalltheLDM typedfeaturestructureof theDCU Johnsmiledrepeatedin Figure4.23,where
basicrepresentsDCU typeand (/z�{q| representsthesemanticsof Johnsmiled13.}~~��� j�(�+'iSEM (qz�{/|SCHEMA (qz�{/|
�&���Figure4.23:LDM ElementaryDCU
In DTAG, this featurestructureis identifiedwith boththetopandbottomfeaturesof anelemen-
taryDCU, asshown in Figure4.24.}~~~~~~~�TOP
}� � jq(C+'iSEM (qz�{/| ��BOTTOM
}� � jq(C+'iSEM (qz�{/| ���&��������
Figure4.24:DTAG ElementaryDCU
13Thevalueof theSCHEMAfeatureis identicalto theSEM featurein LDM elementaryDCUs.
183
![Page 201: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/201.jpg)
RecallfurthertheLDM list grammarrule from Chapter2 shown againin Figure4.2514, which
statesthat any two discoursetreescancombineto form a new treeof type list that representsa
list relation(indicatedby SEM). The valueof an additionalSCHEMA featureis requiredto be a
non-trivial generalizationover themeaningof thetwo trees.}~~� ),+#(CbSEM ),+#(Cb�z4��.�_ M �%� .�_�gC|SCHEMA ^q.�W�z4� .�_�M*�%� .�_ g |
�&��� K}~~� -pb�op.C.SEM � .�_ MSCHEMA ��i�V;.�_�jXM
�&��� ,
}~~� -pb�op.C.SEM � .�_�gSCHEMA ��i�V;.�_�j g
�&���Figure4.25:LDM List Rule
Again, in DTAG eachnodeis expandedto containboth top andbottomfeatures,therebypro-
ducingthegeneralizedDTAG R treeversionshown in Figure4.2615. In this tree,R is instantiated
by thediscourserelationholdingbetweendaughters,(e.g. list, cause, etc.). As shown, thebottom
featuresof theparentnodeis theconjunctionof theapplicationof R to thebottomfeaturesof the
childrennodes(A andB) with top features(TA andTB) of thechildrennodes.}~� TOP î SEM T ïBOTTOM î SEM R(A,B) J TA J TB ï �&��ð ð ð ð ð ð ðñññññññ}~� TOP î SEM TAï
BOTTOM î SEM Aï � ��}~� TOP î SEM TBïBOTTOM î SEM Bï � ��
Figure4.26:DTAG R Tree
Gardentstatesthat her versionof the FTAG substitutionoperation,called - -substitution,is
unchangedexceptthatit is restrictedto thesubstitutionof any treeinto theright leaf of any � tree.
Her illustrationof the - -substitutionoperationis shown in Figure4.27.
DTAG’s versionof the FTAG adjunctionoperation,called - -adjunction,is also unchanged,
exceptthat it is limited to the right frontier andis no longerlimited to “recursive structures”(e.g.
14Thesegrammarrulesaresimplified; see[Pol96] for additionalinformation that is containedin a completeLDMfeaturestructure.
15Gardentdoesnot includetheSCHEMAfeature.
184
![Page 202: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/202.jpg)
optionalmodificationstructureswhoseroot andfoot nodesareidentical).Her illustrationof the - -adjunctionoperationis shown in Figure4.28.Althoughnotshown in thefigure,[Gar97b, 12] states
that “on adjoining,the treedominatedby the leftmostdaughterof the local treebeingadjoinedis
‘closed-off ’ in thatall its b and � categoriesareunified(which in effect preventsany adjunctionto
thissubtree)”.This meansnodesnoton theright frontier arenotavailablefor processing16.
Figure4.27: [Gar97b]’s - -Substitution
Figure4.28: [Gar97b]’s - -Adjunction
As illustration,consider[Gar97b]’sexplanationof thederivationsof thediscoursein (4.21).For
clarity, sheremovesbracketingandfeaturestructurelabeling.
(4.21a) Dick doesnot cometo work
(4.21b) becausethetrainsaren’t running
(4.21c) andbusesaren’t either.
Gardentassertsthat theDCU for (4.21b)canbe - -substitutedinto thecausalR tree. This tree
is then - -adjoinedto the DCU for (4.21 a), making it unavailable for further processing,and its
16Gardentalsoarguesthattheattachmentoperationcanbemodeledusing ê -adjunction.
185
![Page 203: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/203.jpg)
featuresunify. The result is shown in the first tree in Figure 4.29, where j and � representthe
eventualitiesdescribedby (4.21a)and(4.21b)respectively. TheelementaryDCU for (4.21c)is then- -substitutedinto thelist R tree.This treeis then - -adjoinedto the(b) nodeof thefirst tree,making
it unavailablefor furtherprocessingandits featuresunify, yielding thesecondtreein Figure4.29.
Whenprocessingis complete,all remainingtop andbottomfeaturesunify. The semanticsof the
rootbecomes:cause(a,b)J a J list(b,c) J b J c.�T
cause(a,b)J a J TB�Ï ÏÐÐ�a
a� �TB
b �K �
T
cause(a,b)J a J TB�� � � ������a
a� �TB
list(b,c) J b J TC�Ï ÏÐÐ�b
b� �TC
c �Figure4.29:First DTAG Derivationof Example(4.21)
Thereis anotherinterpretationof (4.21),however, namelythat both � and i togethercausej .Gardentarguesthatthis interpretationcanbederivedif (4.21c) first - -substitutesinto thelist R tree,
which then - -adjoinsto (4.21b), yielding thefirst treein Figure4.30. This treethen - -substitutes
into causalR tree.Theresultis then - -adjoinedto (4.21a),yielding thesecondtreein Figure4.30.
Whenprocessingis complete,all remainingtop andbottomfeaturesunify. The semanticsof the
rootbecomes:cause(a,(list(b,c)J b J c)) J a J list(b,c) J b J c.�T1
list(b,c) J b J TC�Ï ÏÐÐ�b
b� �TC
c �K �
T0
cause(a,(list(b,c)J b J TC)) J a J T1�� � � ������a
a� �T1
list(b,c) J b J TC�Ï ÏÐÐ�b
b� �TC
c �Figure4.30:SecondDTAG Derivationof Example(4.21)
186
![Page 204: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/204.jpg)
In its essence,DTAG presentsa viable approachto obtainingthe compositionalsemanticsof
a discoursefrom its discoursetree. However, it is not clear that the featurestructuresin Figures
4.29and4.30havebeenconstructedaccordingto thedefinitionsof - -substitutionand - -adjunction.
“Irrelevant information” hasbeenomittedfrom thesefigures[Gar97b, 15]; if we stepthrougheach
stage,however, it is not clearthatwe would yield thesamefeaturestructures.Consideragainthe
secondderivationof (4.21).To avoid conflatingtheidentitiesof theTB variablesin thetwo R trees
involved in this derivation,we will useTX in onetree,andTZ in theothertree. In thefirst step,
theDCU for (4.21c) - -substitutesinto theright daughterof the list R tree,which by definitionof- -substitutionproducestheunionof thetopandbottomfeaturesasshown in Figure4.31.�T1
list(X,C) J TX J TC�ú úûû�TX
X � �TC
C �+�c
c� K �T1
list(X,C) J TX J TC�� � �����TX
X � �TC U c
C U c �Figure4.31:StepOnein theSecondDTAG Derivationof Example(4.21)
In the secondstep,the list R tree - -adjoinsto the DCU for (4.21 b), which by definition of- -adjunctionproducestheunionof thetop featuresof theDCU for (4.21b) with thetop featuresof
theparentnodeof the list R tree,andtheunionof thebottomfeaturesof theDCU for (4.21b) with
thebottomfeaturesof theleft daughternodeof the )r+�(�b R tree,asshown in Figure4.32.�T1
list(X,C) J TX J TC�� � �����TX
X � �TC U c
C U c �+�b
b� K �b U T1
list(X,C) J TX J TC�Í Í ÍÎÎÎ�TX
b U X� �TC U c
C U c �Figure4.32:StepTwo in theSecondDTAG Derivationof Example(4.21)
The result is not identicalto thefirst treein Figure4.30,which is Gardent’s representationof
this stage.Part of thedifferenceis dueto thefact that the leaf correspondingto (4.21b) hasbeen
pushedoff the right frontier, so accordingto the definition for - -adjunction,its top and bottom
187
![Page 205: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/205.jpg)
featuresunify. Theresultis thatTB andB areinstantiatedasthesingleavailablevalue, � . We can
thenreplaceall otherinstancesof thesevariableswith � , producingthetreein Figure4.33.�b U T1
list(b,C) J b J TC�� � �����b
b� �TC U c
C U c �Figure4.33:StepThreein theSecondDTAG Derivationof Example(4.21)
This treeis still not identicalto Gardent’s version.Onereasonis thatwe have not fully unified
the rightmostleaf, becauseit is not clearwhat Gardenthasdone. ShehasreplacedC with i , but
shehasnot replacedTC with i . Both TC andC arevariablesand i is a value,andall areof like
type (e.g. BOTTOM-SEM and TOP-SEM,respectively). We will thus completethe derivation
without resolvingvariablesafter theunionof featuresat right frontier nodes,andseewhatresults.
Anotherdifferenceis thatGardenthasnot shown theunion“b U T1” in theparentnode,aswould
beexpectedby - adjunction.Gardentdoessaythat - -adjunctionto a leaf is a specialcase,but this
unionwouldalsobeproducedafteradjunctionat othernodes.Wewill thusincludethisunion.
In stepfour the list tree - -substitutesinto the right-mostleaf of a causeR tree,producingthe
unionof thetopandbottomfeatures,asshown in thethird treein Figure4.34.Notethatin Gardent’s
version(thesecondtreein Figure4.30),GardenthasidentifiedZ with list(b,c)J bJ TC, andshehas
also identifiedTZ with T1, in contrastto above,whereshedid not identify TC with i .�T0
cause(A,Z)J TA J TZ�Ï ÏÐÐ�TA
A � �TZ
Z �+
�b U T1
list(b,C) J b J TC�� � �����b
b� �TC U c
C U c �K �
T0
cause(A,Z)J TA J TZ�� � � ������TA
A � �TZ U b U T1
Z U list(b,C)J bJ TC�� � �����b
b� �TCU c
C U c �Figure4.34:StepFour in theSecondDTAG Derivationof Example(4.21)
In stepfive, theresultingcausetree - -adjoinsto theDCU for (4.21a),yielding thethird treein
188
![Page 206: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/206.jpg)
Figure4.35.�T0
cause(A,Z)J TA J TZ�� � � ������TA
A � �TZ U b U T1
Z U list(b,C)J bJ TC�� � �����b
b� �TC U c
C U c �
+�a
a� K �aU T0
cause(A,Z)J TA J TZ�� � � � �������TA
a U A� �TZ U b U T1
Z U list(b,C)J bJ TC�� � �����b
b� �TC U c
C U c �Figure4.35:StepFive in theSecondDTAG Derivationof Example(4.21)
Now theleafcorrespondingto (4.21a)hasbeenpushedoff theright frontier, soby - -adjunction,
its variablesareinstantiatedas j , asareall instancesof TA andA, producingthetreein Figure4.36.�a U T0
cause(a,Z)J a J TZ�� � � ������a
a� �TZ U b U T1
Z U list(b,C)J bJ TC�� � �����b
b� �TC U c
C U c �Figure4.36:StepSix in theSecondDTAG Derivationof Example(4.21)
At this point thereis no moreinput andso all top andbottomfeaturesunify. The problemis
that in mostnodescontainingvariableswe no longerhave a singlevaluewith which they canbe
identified.We do have a singlevaluein our rightmostleaf, sowe unify TC andC with i , andthen
identify all otherinstancesof TC andC with i , producingthetreein Figure4.37.
Again,however, this treedoesnot correspondto Gardent’s intendedfinal derivation for (4.21).
In orderto reproduceherintendedderivation,wehave to understandwhy topfeaturesof elementary
DCUsarenot alwaysidentifiedwith top featuresin thesubstitutednodeaftersubstitution,andwe
have to understandwhy top featuresof nodesbeingadjoinedto arenot unified with top features
in theparentnodeof theadjoiningtree. As statedabove, [Gar97b, 12] doesassertthatadjunction
to a leaf is a “specialcase”,but shedoesnot defineit, andthe sameproblemswould ariseafter
189
![Page 207: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/207.jpg)
adjunctionatothernodeson theright frontier.�a U T0
cause(a,Z)J a J TZ �� � � ������a
a� �TZ U b U T1
Z U list(b,c)J bJ c�÷ ÷øø�b
b� �c
c�Figure4.37:StepSevenin theSecondDTAG Derivationof Example(4.21)
One way to reproduceGardent’s final derivation would be to explicitly statehow features
“unify”after adjunctionand substitution. We would requirethat in substitution,the bottom fea-
turesof the parentnodearereplacedby the bottomfeaturesof the substitutingnode,but the top
featuresof thesubstitutingnodearereplacedby the top featuresof the incomingnode. In Figure
4.27,thiswouldbe � � K � � and b � K b � . Wewouldrequirethatin adjunction,thebottomfeatures
of the left daughterof theadjoiningtreearereplacedby thebottomfeaturesof the treebeingad-
joinedto, but top featuresof theadjoiningtreereplacetop featuresof thetreebeingadjoinedto. In
Figure4.28,thiswouldbe � ��� K � � and b � K b � . Alternatively, wemightdefinesubstitutionnodes
ashaving only top featuresasin FTAG, andelementaryDCUsashaving only bottomfeatures;we
would thenonly have to definehow adjunctionaffectedfeatureunification.
4.3.3 A Syntax-SemanticInterface for DLTAG Derivation Trees
Becausein DLTAG, discourseconnectivesarepredicates, bothsyntacticallyandsemantically, DL-
TAG canbuild boththesyntaxand thecompositionalsemanticsof thesepredicatesusingthesame
syntacticandsemanticmechanismsthatareusedto build thesyntaxandcompositionalsemantics
of predicatesat theclauselevel.
As discussedabove, DLTAG currentlyusestheLTAG grammarto build discoursesyntax. As
such,in thissectionweexplorehow the[JKR03,Kal02, KJ99, JVS99]syntax-semanticinterfacefor
LTAG,whichemploysaflat semanticrepresentationusingideasfrom Minimal RecursionSemantics
190
![Page 208: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/208.jpg)
([CFS97])andHole Semantics([CFS97,Bos95]), canalsoapply to DLTAG. This sectionwill be
exploratoryratherthanconclusive,asacompletesyntax-semanticinterfaceincorporatingall aspects
of DLTAG anddiscourseconnectivesrequiresa thesisin its own right.
As introducedin Section4.2, [JKR03, Kal02, KJ99, JVS99] argue that producinga compo-
sitional semanticsfor LTAG shouldcorrespondto establishingsemanticpredicate-argumentrela-
tionshipsusingthe LTAG derivation tree,becauseit is this tree,ratherthanthe derived tree,that
reflectstheserelationships.To illustratethe basicsof the extensionof their interfaceto DLTAG,
we begin with a few simpleexamplesof two-sentencediscoursesconnectedby structuraldiscourse
connectives.Wewill thenconsidermorecomplex discoursesanddiscusswhy [JKR03, KJ99]’suse
of multipcomponentTAGsand/or[Kal02]’s enrichedderivation treeis sometimesneededto build
thecompositionalsemanticsof discourse.
Considerfirst (4.22),wheretwo clausesarelinkedby thesubordinatingconjunctionbecause.
(4.22)JohnlikesMary becauseshewalksFido.
The elementaryDLTAG treesfor (4.22) are shown in Figure 4.38. SC representssubordi-
nating conjunction. Although the internalstructureof clausesis accessiblein the DLTAG parse
([FMP�
01]), in all of ourexamplesin thissectionwe modelatomicclauseswith elementaryinitial
trees(e.g. �B�@����! ). As discussedabove, D 5 is a genericdiscourseunit root label usedto represent
bothatomicclausesandconstituentscomposedof clausesandpredicates.
D 5� � � �����D 5 Ë SC
because
D 5 Ë D 5�B�@����! D 5��������Figure4.38:DLTAG ElementaryTreesfor Example(4.22)
Figure4.39shows thesemanticrepresentationsof theelementarytreesin Figure4.38. In these
andall of our following semanticrepresentationswewill employ thesemanticsoutlinedin [JKR03,
Kal02, KJ99]. In our discourse-level extension,however, their propositionallabels,e.g. ) � , will
now be associatedwith the semanticsof j/)E) discourseunits, both atomicandcomplex, andtheir
191
![Page 209: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/209.jpg)
propositionalvariables,e.g. ( � , will now beusedasdiscourseunit variables,whosevaluesarethese
labels. Furthermore,we will employ a simplified representationof clausesemantics,akin to the
treatmentof NPsin [Kal02], in which thevaluesof theclauseargumentsarealreadyprovided.For
example,we will use ) g��p),+#äy.��2z�{p��_Å| for thesemanticvalueof theclauseJohnlikesMary.��12!�34��5*'! �B�@����!� ���$�%�&��l M : because’(sM , sg )——————————arg: Û sM ,(1)t , Û sg ,(3)t l g : like’(j, m)
—————arg: –
l � : walk’(m, f)—————arg: –
Figure4.39:SemanticRepresentationof �B12!#3'��5*#! , �B�@����!� and ���������As shown, becausetakes two substitutedargumentsthat are associatedwith positionsin its
elementarytree. Figure4.40 shows the derived andderivation treesthat result from substituting�B�@����! and ���$�%�&� into thesepositionsin �B12!#34��5*#! , alongwith thesemanticrepresentationthatresults.
D 5� � � � ������D 5�B�@����! SC
because
D 5���������B12!#3'��5*#!� � �������&���8! (1) �������&� (3)
l M : because’(lg , l � ), l g : like’(j, m), l � : walk’(m, f)———————————————————–arg: –
Figure4.40:DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.22)
As discussedin Section4.2, combiningsemanticrepresentationsin this approachconsistsof
building theunionof thesemanticrepresentationsof theelementarytreesinvolvedin thederivation
andassigningvaluesto argumentvariables,wherethederivationtreeindicateshow argumentvari-
ablesgetvalues:whena treeis substituted,its valueis appliedto theargumentvariablepairedwith
thepositionat which it attaches.For example,thederivation treein Figure4.40indicatesthat the
sM argumentvariablein thebecauseelementarytreeshouldbeassignedthe labelof �B�@����! because�B�@����! substitutesin at position(1) andposition(1) is associatedwith thesM argumentvariable. In
thesameway, thederivation treeindicatesthat sg shouldbeassignedthe label of ���$�%�&� . Theflat
192
![Page 210: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/210.jpg)
semanticsshown in Figure4.40leadsto theembeddedsemanticrepresentationin (4.23).
(4.23)like’(j, m) J like’(m, f) J because’(like’(j, m), walk’(m, f))
Theanalysisof a discoursecontainingthecoordinatingconjunctionand andtwo clausalargu-
mentsproceedssimilarly17. Considerfor examplethediscoursein (4.24).
(4.24)Johnsaw Mary andhekissedher.
The elementaryDLTAG treesfor (4.24)areshown in Figure4.41. CC indicatescoordinating
conjunction. This analysisalsoappliesto theemptyconnective, 0 , asdiscussedabove.
D 5Í Í ÍÎÎÎD 5 Ì CC
and
D 5 Ë D 5� #!#! D 5�B�8���Figure4.41:DLTAG ElementaryTreesfor Example(4.24)
Figure4.42shows thesemanticrepresentationsof theelementarytreesin Figure4.41.Only the
substitutedargumentof and(sg ) is linkedto anaddress;asdiscussedin Section4.2,in asubstitution
stepat position P , the argumentvariablelinked to P will get the valueof the substitutedelement,
andin anadjunctionstep,theargumentvariableof theincomingtreeis addedto therepresentation
andassignedthevalueat thepositionwhereit attaches.� ����� � #!#! ���8�"�l M : and’(sM , sg )————————arg: sM , Û sg ,(3)t l g : see’(j,m)
—————arg: –
l � : kiss’(j, m)—————arg: –
Figure4.42:SemanticRepresentationof� ���7� , � '!�! and �B�8�"#
Figure4.43shows thederivedandderivation treesthatresultfrom substituting�B�8�"# into� ���7�
andadjoining� ���7� to � #!#! , alongwith thesemanticrepresentationthatresults.Again,thederivation
treein Figure4.43 indicatesthat thevalueof thesg argumentvariablein theand elementarytree
is assignedthe semanticlabel of ���8�"# , andfurther indicatesthat the sM argumentvariablein the
17As discussedabove,so,but take aninitial tree,andareanalysedlike because.
193
![Page 211: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/211.jpg)
andelementarytreeis addedto therepresentationandassignedthesemanticlabelof � #!�! . Thisflat
semanticrepresentationleadsto theembeddedsemanticrepresentationshown in (4.25).
(4.25)see’(j,m) J kiss’(j, m) J and’(like’(j, m), kiss’(j, m))
D 5Í Í Í ÍÎÎÎÎD 5� '!�! SC
and
D 5�B�8�"#� '!�!� ���7� (0)�B�%�"� (3)
l M : and’(lg , l � ), l g : see’(j,m), l � : kiss’(j, m)——————————————————arg: –
Figure4.43:DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.24)
Considernow themorecomplex discoursein (4.26). Theargumentsof becauseareitalicized,
andthe argumentsof and arebracketed. To make it clear that thesearethe interpretedsemantic
argumentsof eachconnective,we includeacontextual question.Figure4.44shows thederivedand
derivation treesandthe semanticrepresentationfor (4.26) after substituting�����D;��� ¿�¿ 9 and �B���6�7�into ��12!�34��5*'! , substituting���"�DA#��� into
� ���7� , andadjoining� ����� to the o7T7T�b of the � .Ci�j`k�(*. tree.
(4.26)(Who is happy andwho is sad?)
[Mary is happybecauseherhusbandfounda job] and[Johnis sad].
D 5� � � � � �ú ú ú������D 5� � � � �ö ö�����
D 5���"�D;��� ¿�¿ 9 SC
because
D 5�B���6�7�CC
and
D 5�����DA#����B12!#34��5*#!� � � � � �� ����������"�D;��� ¿�¿ 9 (1) �B���6�7� (3)
� ����� (0)���"�DA'�%� (3)
l � : is-happy’(m), l ç : find’(h, j), l : is-sad’(j),l M : because’(l� , l ç ), l g : and’(lM , l )————————————————————————————————-arg: –
Figure4.44:DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.26)
Thisflat semanticrepresentationleadsto theembeddedsemanticrepresentationshown in (4.27).
194
![Page 212: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/212.jpg)
This is theexpectedinterpretation;by adjoiningto therootof thebecausetree,thevalueof theand
adjunctionargumentvariableis thelabelcorrespondingto theentirebecausetree.
(4.27)is-happy’(m) J find’(h, j) J is-sad’(j)J because’(is-happy’(m), find’(h, j)) J and’(because(is-happy’(m), find’(h, j)), is-sad’(j))
But now considerthesimilardiscoursein (4.28).Again,theargumentsof becauseareitalicized,
the argumentsof and arebracketed,and to make it clear that theseare the interpretedsemantic
argumentsof eachconnective,we includeacontextual question.Figure4.45shows thederivedand
derivation treesandthe semanticrepresentationfor (4.28) after substituting�����D;��� ¿�¿ 9 and �B���6�7�into ��12!�34��5*'! , adjoining
� ����� to theleaf ( �����6��� ) of theresult,andsubstituting�B�@����! into� ���7� .
(4.28)(Why is Mary happy?)
Mary is happybecause[herhusbandfounda job] and [helikesit].
D 5� � � � � � � �������D 5���"�D;��� ¿�¿ 9 SC
because
D 5Í Í Í ÍÎÎÎÎD 5�����6��� CC
and
D 5���&���8!��12!�34��5�'!Í Í Í ÍÎÎÎÎ���"�D;�C� ¿�¿ 9 (1) �����6��� (3)� ���7� (0)�B�@����! (3)
l � : is-happy’(m), l ç : find’(h, j), l : like’(h, j), l M : because’(l� , l ç ), l g : and’(lç , l )————————————————————————————————-arg: –
Figure4.45:DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.28)
Thisflat semanticrepresentationleadsto theembeddedsemanticrepresentationshown in (4.29).
(4.29)is-happy’(m) J find’(h, j) J like’(h, j)J because’(is-happy’(m), find’(h, j)) J and’((find(h,j)), like’(h, j))
Assumingthat Mary beinghappy is causedby both her husbandfinding a job and liking it,
this is not the interpretationproducedby this approach,wholly becausetheand adjunctionis not
retrievedfrom theargumentposition(3) of becausein thederivationtree18.
18Note that theproblembecomesenormouslymorecomplex whenwe considerthe currentDLTAG parser’s “lowestadjunction”default for theemptyconnective. See[FMP Ñ 01] for detailsaboutthisdefault.
195
![Page 213: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/213.jpg)
In fact,thesameproblemarisesin clause-level conjunction.Considerfor example(4.30).
(4.30)JohnlikesMary andSue.
In (4.30),theunit Mary andSueis built by adjunctionof an j`WU- treeto � j/o�� , andthesubsti-
tutionof Sueinto theandtree.Theand treehereis identicalto auxiliaryandtreein DLTAG,except
that its root, substitutionandadjunctionnodesareall labeledNP. This tree,alongwith theLTAG
derived andderivation treesfor (4.30), are shown in Figure4.46. As shown, the compositional
semanticsof theverbis likes(j,m), because� � ��<�9 is whatsubstitutesinto address(2.2).
NPÍ Í ÍÎÎÎNPÌ CC
and
NPË SÍ Í Í ÍÎÎÎÎNP
John
VPÍ Í Í ÍÎÎÎÎV
likes
NPÍ Í Í Í� �ÎÎÎÎNP
Mary
CC
and
NP
Sue
���&�6��!Í Í ÍÎÎÎ�� %����� (1) � � ��<�9 (2.2)� ����� (0)� 45*! (3)
Figure4.46:LTAG DerivedandDerivationTreesfor Example(4.30)
Onesolutionat theclauselevel is to make theNP-conjoiningj/WU- treeinto an initial tree,but
althoughthis would solve theproblemin (4.30),it is not only NP conjunctionthatyields this type
of problem;any adjunctionto a substitutedelementwill not be reflectedin thesecompositional
semantics19. This solutioncouldalsobeappliedat thediscourselevel, e.g. if DLTAG modelsand
(and 0 ) with initial trees;thentheand treein example(4.28)couldsubstituteinto position(3) in the
becausetree,andproducethedesiredinterpretation.
Thereis moregeneraltechnicalsolutionproposedin [Kal02] to dealwith scopein Frenchquan-
tifiers,whichhave beenanalyzedasadjunctsthatadjointo anNP, asillustratedin Figure4.47.We
overlookdetailsof thesemanticsof Frenchquantifiershere;roughlystated,thequantifiersemantics
19This solutionfor NP coordinationwassuggestedseparatelyby LauraKallmeyer andAravind Joshi,personalcom-munications.As Aravind Joshinotes,it is naturalfor NP coordinationto be representedin LTAG with an elementarytreebecauseany NP treein LTAG hasthe (root) label NP; however, VP, whosecoordinationcanalsobe viewed asScoordinationin which two subjectnodesareidentified,doesnot exist in LTAG asanelementarytreewhoseroot label isthesameasanelementarytreethatcouldconjoin it; rather, theroot labelof theVP treeis S. He suggestsinsteadthataVP coordinationtreebeconstructeddynamicallyduringparsing.
196
![Page 214: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/214.jpg)
requiresaccessto the verb semantics,andvice versa,but thereis no link (edge)in the derivation
treebetweenthem20.
NÖ Ö××DET
chaque
N Ì + N
chien
+ S÷ ÷øøNË VP
V
aboie
K SÍ Í ÍÎÎÎNú úûû
DET
chaque
N
chien
VP
V
aboie
, aboie
chien(1)
chaque(0)
Figure4.47:Quantifiersin French
[Kal02, 104]’s solutionto this problemis to enrichthederivation treewith anadditionaledge
betweenthequantifierandtheVP, asshown in Figure4.48.
aboie
chien(1)
chaque(0)
Figure4.48: [Kal02]’s . -Edgesfor Quantifiersin French
This additionallink, it is argued,makesexplicit the intuitive dependency relationshipswe can
alreadyseein thederivationtreebetweentheVP treeinto whichchiensubstitutes,andelementsthat
adjointo chien. In otherwords,[Kal02] proposesthat in thecaseof anadjunctionat theroot node
of someelementarytree � (in this casechien), the adjoinedtree(in this casechaque) is not only
linkedby anedgeto � , but is alsolinkedby anadditionaledgeto thetreeto which � wasaddedin
somepreviousderivationstep,which is in thiscasethetreefor aboie. [Kal02] notesthatin factthis
additionaledgereflectstheunificationof featuresaftersubstitutionof annodeW (whichcreatesthe
unionof top features(seeFigure4.21))followedby adjunctionat W (whichcreatestheunionof the
top featuresin theparenttreewith thetop featuresof W (seeFigure4.22)).
More generally, [Kal02] proposesthe following definition of the e-derivation graph(it is no
longera tree): all edgesin the derivation treeareprimary e-derivation edges.Furthermore,there
20Translation:chaque= each; chien=dog; aboie=barks
197
![Page 215: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/215.jpg)
is a secondary. -derivation edge( . -edge)betweentwo nodesª and�
if, in the derivation tree,
therearenodesª ’,� M ,...� � suchthat ª ’ is a daughterof ª ,
� M is a daughterof ª ’ with position0
(adjunctionat therootnodeof ª ’),� � � M is adaughterof
� � with position0 (1 � i Û n) and� � =
�.
Thisdefinitionis sketchedin Figure4.49. ªª ’� M (0)
...� � (0)
Figure4.49: [Kal02]’s . -DerivationGraph
[Kal02] then redefineshow substitutionand adjunctionyield the semanticrepresentationto
incorporatethe contribution of . -edges.By her new definitions,a variablein the semanticrepre-
sentationof a nodecanobtain its value either from a tree linked to it by a primary edgein the
derivation tree,or from a treelinked to it by a secondary. -edgein the . -derivation structure.For
example,avariablein thesemanticrepresentationof aboiecanobtainits valuefrom eitherchienor
chaque. Theonly furtherrequirement,obviously, is that thevariableandthevalueit obtainsareof
like semantictype.
Returningnow to the DLTAG example(4.28),what addingthe additional . -edgeseffectively
doesis createambiguityasto the interpretedsemanticargumentof because, becauseall variables
andvalueswe have consideredso far areof like semantictype (e.g. discourseunits). Consider
the . -derivationgraphfor (4.28),shown in Figure4.50alongwith thederivedtree. If we compute
semanticsbasedonthis . -derivationstructure,thenin additionto thesemanticrepresentationof this
discoursethatwealreadydiscussed,shown in Figure4.45(wherebecausetakesl � : ���"�D;��� ¿�¿ 9 andl ç :�����6��� asits arguments),thereis anotherpossiblesemanticrepresentationfor this discourse,shown
in Figure4.51.Thisadditionalinterpretation,which leadsto theembeddedsemanticrepresentation
shown in (4.31),is theintendedinterpretation.It is producedby theadditional. -edge,whichmakes
198
![Page 216: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/216.jpg)
availablethevalueof theand treeto theargumentvariablein thebecausetree.
(4.31)is-happy’(m) J find’(h, j) J like’(h, j) J and’(find’(h, j), like’(h, j))J because’(is-happy’(m), and’(find’(h, j), like’(h, j)))
D 5� � � � � � � �������D 5���"�D;��� ¿�¿ 9 SC
because
D 5Í Í Í ÍÎÎÎÎD 5�����6��� CC
and
D 5���&���8!��12!�34��5�'!Í Í Í ÍÎÎÎÎ���"�D;�C� ¿�¿ 9 (1) �����6��� (3)� ���7� (0)�B�@����! (3)
Figure4.50:DLTAG DerivedTreeand . -DerivationGraphfor Example(4.28)
l � : is-happy’(m), l ç : find’(h, j), l : like’(h, j), l M : because’(l� , l g ), l g : and’(lç , l )————————————————————————————————-arg: –
Figure4.51:Additional SemanticRepresentationfor (4.28)dueto . -DerivationGraph
The questionthenbecomesoneof whetherwe want this ambiguity. We certainlywant some
ambiguity, the problemis that we may not want the first interpretationof (4.28) to be possibleat
all. Thatis, we don’t wantto producearepresentationfor (4.28)wherebecausetakesl � : �����D;��� ¿�¿ 9andl ç : �B���6�7� asits arguments,andand takes l ç : �����6��� andl : ���&���8! , becauseit is not clear that
this is even a possibleinterpretationof of (4.28). Nor, perhaps,do we want the . -edgein Figure
4.50to allow j`WU- to resolve its adjunctionvariableto the interpretationof because. While doing
so introducesa possibleinterpretation,in fact this is the sameinterpretationalreadyachieved by
adjunctionof theand treeto therootof because, aswe saw in (4.26).
In otherwords,thereappearto beonly two possibleinterpretationsfor (4.28),oneis achieved
by adjunctionof and to the root of the becausetree, and the other is madeavailable by the . -edgethat allows becauseto take the and tree as its secondargument. The third representation,
wherebecausetakes �����6�7� asits secondargumentandand takes �����6�7� asits first argument,is not
clearly interpretable.To prevent suchunwantedinterpretationsarisingfrom DLTAG . -derivation
graphs,we could of coursedefineconstraintson the effect that . -edgescanhave on the valueof
199
![Page 217: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/217.jpg)
semanticargumentvariableswhosevaluesarediscourseunit labels. As illustration, let us define
two constraintsthatrestrictthesemanticvaluesmadeavailableby DLTAG . -edges:
Constraint(1): if thereis an . -edgebetweentwo elementaryDLTAG treesthat both take two
structuralarguments(via substitutionor adjunction)whosevaluesareboth discourseunit labels,
thenthis . -edgewill determinethevalueof theargumentof thehigherelementarytree.
Constraint(2): theargumentvalueproducedby Constraint(1) is theonly additionalargument
valuemadeavailableby . -edgesbetweenDLTAG elementarytrees21.
Webriefly illustratetheeffectof theseconstraintsby consideringthediscoursein (4.32),where
the intendedargumentsof becausearebracketed. Thederived treeand . -derivation graphfor this
exampleareshown in Figure4.52.
(4.32)[Mary is happy] because[herhusbandfoundajob andhelikesit andit paysgoodmoney].
D 5ð ð ð ð ð ð ð ðûû ññññññññD 5�����D;��� ¿�¿ 9 SC
because
D 5� � � � �ÚÚ �����D 5�����6�7� CC
and
D 5Í Í Í ÍÎÎÎÎD 5�B�@����! CC
and
D 5� ¿ ��9
�B12!�34��5*#!Í Í Í ÍÎÎÎÎ���"�D;��� ¿�¿ 9 (1) �����6��� (3)� ���7� (0)�B�@����! (3)� ���7� (0)� ¿ ��9 (3)
Figure4.52:DLTAG DerivedTreeand . -DerivationGraphfor Example(4.32)
As thederived treealreadyshows, andConstraint(1) requires,we want thehigherand to take
thevalueof the lower and asthevalueof its substitutionargumentvariable,andwe wantbecause
to take the valueof the higherand asthe valueof its substitutionvariable. Constraint(2) would
prevent the . -edgesfrom allowing any othersemanticinterpretations,suchasthelower and taking
the valueof the higherand asthe valueof its adjunctionargument– becausethis canalreadybe
achievedby adjunctionto therootof thehigherand. Essentially, however, it shouldbeobviousthat
21This cannotbestipulatedat theclauselevel, for chaqueneedsaccessto thelabelof aboie.
200
![Page 218: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/218.jpg)
combining[Kal02] e-derivation graphswith constraintsthat reducethe interpretationsyieldedby
thesegraphsis anattemptto avoid asituationwheretheDLTAG derivationstructure(treeor graph)
producesthewrongresultandthusis notabetterbasisfor semanticinterpretationthansimplyusing
theDLTAG derivedtreein thefirst place.
Thereis an alternative solutionproposedin [JKR03], however, which allows us to derive all
andonly the intendedsemanticinterpretation(s)from theoriginal DLTAG derivation treewithout
requiringtemperingconstraintsor additional . -edges.This solutionemploys thenotionof flexible
directionof composition22, which we illustratefirst usinga context-freegrammar(CFG)rule such
asA K BC. To produceA, wecanview B asa functionandC asits argument,or wecanview C as
thefunctionandB asits argument.BecauseCFGsprovide string rewriting rules,in which function
andargumentare‘string-adjacent’strings,thisuseof flexible compositioneffectsneithertheweak
generative capacity(setof stringsgenerated)nor the stronggenerative capacity(setof derivation
treesgenerated)of theCFG.
A TAG, however, providestreerewriting rules. Functionandargumentin a TAG arecomplex
topologicalarguments(trees)thatare‘tree-adjacent’;thus,dependingonhow it is specified,theuse
of flexible compositionin aTAG canpotentiallyeffectbothits weakandstronggenerativecapacity.
[JKR03] specifytheuseof flexible compositionin aTAG asfollows: if a tree b composesinto atreek , k mustbeanelementarytree. If both b and k areelementarytrees,thedirectionof composition
cango eitherway. If both b and k arederivedtrees,they cannotcomposewith eachother. Roughly
stated,this definitionof flexible compositionallows thederivation treeto betraversedin a flexible
mannerwhile ensuring‘tree locality’: thederivation treecanbetraversedstartingat any node,but
as traversalcontinuesthe growing complex (derived) treecanonly composeinto ’tree-adjacent’
elementarytrees.
To take a simpleexample,considerthe constructionof theclauseFunnypeoplesmile, whose
syntaxandsemanticscanbe producedthroughcompositionof the threeelementaryLTAG trees
shown in Figure4.53alongwith theresultingderivedandderivation trees.Note thatalthoughthe
derivation treerepresentshow theseelementarytreescombine,andthederived treerepresentsthe
22This discussionof flexible compositionin TAG is derivedfrom [JKR03, 8].
201
![Page 219: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/219.jpg)
resultingclausestructure,neitherof thesetreesshow thetraversalorderin which theseelementary
treeswerecomposed.By theTAG definitionof flexible composition,wecanfor examplefirst com-
pose� ¿ !�� ¿ �&! and �� � ���&! andthencomposetheresultingderived treeinto� ��5�����9 23. Alternatively,
we canfirst compose� ��5����*9 and � ¿ !#� ¿ �! , andthencomposetheresultingderivedtreeinto �B � ���! .
NPÖ Ö××ADJ
funny
NPÌ + NP
people
+ SÖ Ö××NPË VP
V
smile
K SÍ Í ÍÎÎÎNPú úûû
ADJP
funny
NP
people
VP
V
smile
, �� � ���&!� ¿ !#� ¿ �! (1)� ��5��*��9 (0)
Figure4.53:Flexible Compositionin LTAG
Althoughthesetraversalordersareall possibleby thedefinitionof flexible compositionin TAG,
only thelatterbottom-uptraversalyield thedesiredsemantics.As illustration,supposetheseman-
tics correspondingto � ¿ !�� ¿ �&! is people’(x), thesemanticscorrespondingto� ��5����*9 is funny’(y), and
thesemanticscorrespondingto �B � ���! is smile’(z). If we first compose� ¿ !�� ¿ �&! and �B � ���&! , then sis identifiedwith people’(x); subsequentcompositionof this derived treewith
� ��5����*9 identifies �with people’(x)too, yielding theclausesemantics:smile’(people’(x))J funny’(people’(x)). How-
ever, if we first compose� ¿ !#� ¿ �! with� ��5�����9 , then � will be identifiedwith people’(x), yielding
funny’(people’(x)). Substitutingthecorrespondingderivedtreeinto �� � �6�! will causes to beiden-
tified with funny’(people’(x)), yielding thedesiredsemantics:smile’(funny’(people’(x))).
In this thesis,it is the impactof flexible compositionon the computationof semanticsfrom
theDLTAG derivation treethat is our mainconcern.First, considerhow flexible compositionand
an assumptionof bottom-uptraversalof the DLTAG derivation tree producesonly the intended
interpretationof (4.28),repeatedbelow, wheretheintendedargumentsof becausearebracketed.
(4.28)(Why is Mary happy?)
[Mary is happy] because[herhusbandfounda job andhelikesit].
Thederivedandderivationtreesfor this examplearerepeatedin Figure4.54.We have already
seenhow a top-down traversalof thederivation treeyieldsanunintendedsemanticrepresentation23Allowing simultaneouscompositionis alsonecessarysoasnot to excludestandardTAG derivations[JKR03].
202
![Page 220: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/220.jpg)
for this clause(seeFigure4.45),Figure4.54shows the intendedsemanticrepresentationfor this
example,which results,very simply, from abottom-uptraversalof thederivationtree.
D 5� � � � � � � �������D 5���"�D;��� ¿�¿ 9 SC
because
D 5Í Í Í ÍÎÎÎÎD 5�����6��� CC
and
D 5���&���8!��12!�34��5�'!Í Í Í ÍÎÎÎÎ���"�D;�C� ¿�¿ 9 (1) �����6��� (3)� ���7� (0)�B�@����! (3)
l � : is-happy’(m), l ç : find’(h, j), l : like’(h, j), l M : and’(lç , l ) l g : because’(l� , l M )————————————————————————————————-arg: –
Figure4.54:DLTAG DerivedandDerivationTreesandSemanticRepresentationfor (4.28)
We will now considertheanalysisof two-sentencediscoursesin which thesecondsentenceis
modifiedby adiscourseadverbial.Wewill show thattheuseof flexible composition,whichallows
a bottom-uptraversalfor DLTAG derivation trees,is sometimescrucial to obtainingthe intended
semanticinterpretation.We will further illustratehow [KJ99]’s enrichedderivation treecould be
usedinstead,but would yield greatersemanticambiguity.
As discussedin Chapter3, the distinctionbetweenclausaladverbials,which do not function
semanticallyasdiscourseconnective, anddiscourseadverbials,which do functionsemanticallyas
discourseconnectives, is derived from their predicateargumentstructureand interpretation.For
example,in (4.33),theinternalargumentof thePPdiscourseadverbial is a demonstrative AO, this
way, which refersto theinterpretationof theprior sentence.
(4.33)Thecompany interviewedeveryone.In thisway, they consideredall theiroptions.
Of course,theanaphoricityof demonstrativeNPreferenceisnotmodeledstructurallyin (D)LTAG;
asdiscussedin Chapter3, theanaphoricityof pronounscanberepresentedsemanticallyusingas-
signmentfunctions[HK98]. In general,[[ � � ]] � à is readas“x denotesanentity . via anindex + that
is mappedto . relative to anassignmentfunction j , where j is determinedby a context i ”. How-
ever, definitenounshave beenrepresentedsemanticallyusingpartial functions: thedomainof the
definitearticlecontainsonly nounsthatcorrespondto one(andonly one)entity in thesetof individ-
203
![Page 221: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/221.jpg)
uals([HK98]). Althougha definitenounthuspresupposesoneandonly oneentity corresponding
to its denotation,it mayor maynot beanaphoricin thesensethat it refersto a saliententity in the
context. Demonstrative NPsaremoreakin to pronounsin that they usuallyare anaphoricin the
above-mentionedsense.However, in LTAG, demonstrative determinersadjoin to an NP andtheir
associatedfeaturestructurecontainsa +definite feature([Gro99, 159]). As statedabove, definite
descriptionsarenot discussedin [JKR03, Kal02, KJ99]; aswe will seebelow, they do discussthe
semanticrepresentationof quantifiers,modelingthemwith a“scopepart” anda“predicate-argument
part”. As definitedeterminersarenotquantifiers([Gro99, 161]),we will extrapolatetheir semantic
representation.We will alsoextend[JKR03, Kal02, KJ99]’s representationof PPsasNP-adjuncts
to PPsasS-adjuncts.
Theelementarytreesfor (4.33)areshown in Figure4.55; to build thediscoursestructure,the
elementarytreerepresentingtheemptyconnective (anchoredby 0 ) is employed.Figure4.56shows
thesemanticrepresentationsof theseelementarytrees.
D 5� � ����PP� �
P
in
NPË D 5 Ì NPÖ Ö××DET
this
NPÌ NP
way
D 5� � ����D 5 Ì 0 D 5 Ë D 5� �6�* "!#<�=���!'� D 5�B34���>4����!#<
Figure4.55:DLTAG ElementaryTreesfor Example(4.33)
� � � � "���" � ����9l M : in’(x M , sM )—————————-arg: Û x M ,(1.2)t , sM this’(pM (z))
—————arg: pM q M : way’
————-arg: –�A: � � �� "!#<�=��6!#� ��3'�#�>'�6��!'<
l g : 0 ’(s g , s� )————————-arg: sg , Û s� ,(3)t l � : interview’(c, e)
———————–arg: –
l ç : consider’(c,o)———————arg: –
Figure4.56:SemanticRepresentationof� �6� , � "���" , � ����9 , �A: , � �6�* "!#<�=���!'� and �B34���7'����!'<204
![Page 222: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/222.jpg)
As shown,� �6� contains� M ; asin [Kal02], � , � , s areargumentvariableswhosevaluesareNP-
denotations.� �6� alsocontains( M , which aswe have alreadystatedis anargumentvariablewhose
valuesarediscourse-unitlabels.� "���" containsp M , which as in [Kal02] is an argumentvariable
whosevaluesareunarypredicates.� �$��9 is labeledwith theunarypredicatevalueq M . Werepresent
theinterpretationof theemptyconnective, e.g. thecontinuationof thediscourse,simply as 0 ’; the
restof its representationis identicalto thatfor and.
Figure4.57 shows the derived tree, derivation tree, and . -derivation graphfor this example,
alongwith thesemanticrepresentationthatwouldresultfrom abottomuptraversalof thederivation
tree, e.g. from adjoining� "���" to � ����9 , substitutingthe result into
� �6� , adjoining the result to�B34���7'����!'< , substitutingtheresultinto� :
, andadjoiningtheresultto � �6�* "!#<�=���!'� .
D 5� � � � � �ûûû ������D 5� �6�* "!#<�=���!'� 0 D 5� � � �����
PPú ú úûûûP
in
NPÖ Ö××DET
this
NP
way
D 5�B34���>4����!#<� � �� "!#<�=��6!#��A:
(0)�B34���7'����!'< (3)� �6� (0)� ����9 (1.2)� "���� (0)
� �6�* "!#<�=���!'��;:(0)�B34���7'����!#< (3)� �6� (0)� ����9 (1.2)� "���" (0)
l � : interview’(c, e), l ç : consider’(c,o), this’(way’(z)), l M : in’(z, l ç ), l g : 0 ’(l � , l M )———————————————————————————————arg: –
Figure4.57:DLTAG DerivedandDerivationTrees,. -DerivationGraphandSemanticsfor (4.33)
This leadsto thefinal semanticrepresentationshown in (4.34).Notethattheanaphoricityof this
wayhasnotbeenrepresentedor resolvedby thecompositionalsemantics.Anaphora/Demonstrative
NP resolutionshoulddeterminethatit refersto l � : interview’(c, e).
(4.34)interview’(c, e) J consider’(c,o) J 0 ’(interview’(c, e), in’(this’(way’(z)), consider’(c,o)))
Clearly, bottom-uptraversalof thederivationtreeyieldstheintendedsemanticinterpretation.If
insteadwe usea top-down traversalof the . -derivationgraph,we couldstill achieve this interpreta-
205
![Page 223: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/223.jpg)
tion. In this case,the . -edgebetween� "���" and
� �6� is crucial; asin [Kal02], the representationof
thedeterminerthiscontainsthearguments which is identifiedwith thesubstitutionargumentatpo-
sition (1.2) in therepresentationof theprepositionvia the . -edgebetweenthem.However, asnoted
above,these. -edges,if notconstrained,allow numerousotherinterpretations.Moreover, Constraint
(1) doesnot requireus to usethe . -edgebetween�A:
and� �6� becauseonly oneof
� �6� ’s arguments
is a discourseunit variable. The interpretationproducedby consideringa top-down traversalof
primaryedgeswould bethatof two separatediscourserelations:therelationconveyedby 0 would
bebetweenthefirst andsecondsentence- the fact that in this wayadjoinsto thesecondsentence
would not bereflectedin the 0 relation. Therelationconveyed by in this waybetweenthesecond
sentenceandtheprior discoursewould bereflectedin a separate formula. Consideringthe . -edge
couldproducestill additionalinterpretations;however, Constraint(2) would preventadditionalin-
terpretationsarisingfrom this . -edge. Clearly, bottom-uptraversalprovidesa betterapproachto
deriving theintendedsemanticinterpretationfrom at leasttheseDLTAG structures.
As shown in Chapter3, however, explicit AO reference,(e.g. this way), is not theonly way an
adverbialcanfunctionasa discourseconnective. Both PPandADVP adverbialsmayalsocontain
hiddendefiniteAO argumentsthatcansometimesbemadeexplicit by aPPmodifier, e.g.asa result
(of that),consequently, for anexample(of that). Considerfor examplethediscoursein (4.35).
(4.35)Mike foundno new clients.Consequently, helosthis job.
The elementaryDLTAG treesfor (4.35) areshown in Figure 4.58. As shown, consequently
takes only a single structuralargument; the discourseunit it modifies. Again, DLTAG usesthe
emptyconnective to build thestructuralconnectionbetweenthetwo sentences.
D 5� � ����ADVP
ADV
consequently
D 5 Ì D 5� � ����D 5 Ì 0 D 5 Ë D 5�����6��� D 5�B�&��'!
Figure4.58:DLTAG ElementaryTreesfor Example(4.35)
206
![Page 224: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/224.jpg)
Figure 4.59 shows the semanticrepresentationsof the elementarytreesin Figure 4.58. As
shown,� 34���7#!#?�5C!#�� "�@9 contains( M , which representsthe interpretationof adjunctionargumentvari-
able,andit alsocontains[[s � ]] � à , which representsa hiddenAO argumentthat mustbe resolved
anaphorically. Herewe experimentwith theexplicit useof anassignmentfunctionto representthis
anaphoricity;becausethe first sentenceyields the intendedvalue for + , we usethe ( variableas
generalizedvariablefor AO interpretations.� 34���>'!�?�5C!#�* "�&9 �;: �����6��� �����'!l M : consequently’([[s� ]] � à , sM )——————————-arg: sM l g : 0 ’(s g , s� )
———————arg: sg , Û s� ,(3)t l � : find’(m, c)
————–arg: –
l ç : lose’(m,j)—————-arg: –
Figure4.59:SemanticRepresentationof� 34���7#!#?�5C!#�� "�@9 , �;: , �����6��� and �����'!
Figure4.60shows thederived tree,derivation tree,and . -derivation graph,alongwith these-
manticrepresentationthatwould resultfrom a bottomup traversalof thederivation tree,e.g. from
adjoining� 3'�#�>#!#?�5C!#�* "�&9 to �B�&��#! , substitutingtheresultinto
� :, andadjoiningtheresultto �����6��� .
D 5� � � � �ûûû �����D 5�����6�7� 0 D 5� � ����
ADVP
ADV
consequently
D 5�����'!�����6�7��;:
(0)�B�&��'! (3)� 3'�#�>#!#?�5C!#�* "�&9 (0)
�����6����A:(0)�B�&��#! (3)� 34���>'!�?�5C!'�� "�@9 (0)
l � : find’(m, c), l ç : lose’(m,j), l M : consequently’([[s� ]] � à , l ç ), l g : 0 ’(l � , l M )————————————————————————————————-arg: –
Figure4.60:DLTAG DerivedandDerivationTrees,. -DerivationGraph,andSemanticsfor (4.35)
This leadsto the final semanticrepresentationshown in (4.36). Again, anaphoraresolution
shoulddeterminethat theanaphorresolvesto l � : find’(m, c). And alsoasin theprior example,the. -derivationgraphwouldproducethis,alongwith numerousother, semanticinterpretations.
(4.36)find’(m, c) J lose’(m,j) JÅ0 ’(find’(m, c), consequently’([[s� ]] ��à , lose’(m,j)))
207
![Page 225: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/225.jpg)
As notedabove and in Chapter3, in PPadverbialssuchasas a result (of that), the internal
argumentcontainsahiddenor overt anaphoricAO argument.Whenthisargumentis overt,we take
thesametackasin [Kal02], wheresimilar binaryNP predicates(e.g. winnerof NP) aremodeled
usingNP elementarytreeswith a substitutedPPargument.Considerfor examplethediscoursein
(4.37).TheelementaryDLTAG treesfor (4.37)areshown in Figure4.61.
(4.37)Mike foundno new clients.Asa resultof that, helosthis job.
D 5� � ����PPÙ ÙÚÚ
P
as
NPË D 5 Ì NPÖ Ö××DET
a
NPÌ NPú ú úûûûNP
result
PP� �P
of
NPËNP
that
D 5� � ����D 5 Ì 0 D 5 Ë D 5�B��� �7� D 5�����'!
Figure4.61:DLTAG ElementaryTreesfor Example(4.37)
As shown, there is no extra elementarytree for the of preposition. Rather, it is treatedas
semanticallyvoid and is part of the elementarytree for result that selectsfor the PP containing
its internalargument.Furthermore,this treecontainsa substitutionsite for this internalargument.
Figure4.62shows thesemanticrepresentationsof theelementarytreesin Figure4.61.� �8 � � ��<�!�'5C�@ ED;��� �� "���� l M : as’(xM , sM )————————–arg: Û x M ,(1.2)t , sM a’(pM (z))
————arg: p M qM : ß y[result-of’(y, x g )]
—————————–arg: Û x g ,(2.2)t that’([[x � ]] ��à )
—————-arg: –�;: �����6��� �����#!
l g : 0 ’(s g , s� )———————arg: sg , Û s� ,(3)t l � : find’(m, c)
————–arg: –
l ç : lose’(m,j)—————-arg: –
Figure4.62:SemanticRepresentationof� �8 , � � , ��<�!�'5C�@ ED;��� , �� "���� , � : , �����6�7� and �B�&��#!
As shown,� �8 contains(>M , which asusualrepresentstheinterpretationof theadjunctionargu-
208
![Page 226: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/226.jpg)
mentvariable,andit alsocontainsx M , whichrepresentsthesubstitutedNP. Wealsofollow [Kal02]’s
representationof thequantifier j , exceptthatwe condensethescopeandpredicatepartsinto a sin-
gle formula; we will discussscopeissuesbelow. Note that j suppliesthe individual variablefor
thebinarypredicateresult, andtakesanargumentvariablep M to thispredicate.Following [Kal02]’s
representationof thebinarypredicatewinner-of, result-of is representedasabinarypredicatevalue;
it takesa substitutedargumentandtheentity it denotesis treatedasa boundvariablewhichwill be
instantiatedwith theindividual variablesuppliedby j (z). We treatthepronounthat asdenotingan
entity � whosevaluemustbefixedby anassignmentfunction.
Figure4.63shows thederivedandderivationtrees,. -derivationgraphandsemanticsthatresult
from adjoining� � to ��<�!�'5C�@ ED;��� , substituting�� "�C�� into theresult24, substitutingtheresultinto
� �% ,adjoiningtheresultto �B�&��#! , substitutingtheresultinto
�;:, andfinally adjoiningtheresultto �����6��� .
D 5ð ð ð ð ð ð ð���� ñññññññD 5�����6��� 0 D 5� � � � � �������
PPÍ Í ÍÎÎÎP
as
NPÍ Í ÍÎÎÎDET
a
NPú ú úûûûNP
result
PP� �P
of
NP
that
D 5�B�&��'!�����6���� :
(0)�B�&��#! (3)� �% (0)��<�!�'5C�@ ED;��� (1.2)� � ����� � (0) �� "���� (2.2)
�����6���� :(0)�����#! (3)� �% (0)��<�!�'5C�@ ED;��� (1.2)� � ����� � (0) �� "���� (2.2)
l � : find’(m, c), l ç : lose’(m,j), l M : as’(a’(ß y[result-of’(y, that’([[x � ]] � à ))](z)), l ç ), l g : 0 (l � , l M )————————————————————————————————-arg: –
Figure4.63:DLTAG DerivedandDerivationTrees,. -DerivationGraphandSemanticsfor (4.37)
This leadsto thefinal semanticsshown in (4.38).Again,anaphoraresolutionshoulddetermine
that the anaphoricreferenceof the explicit internalargumentof result resolvesto l � : find’(m, c).
24Thetraveralbeginsat frontier nodes;left or right orderingdoesnotmatter.
209
![Page 227: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/227.jpg)
Notethatif wechoseinsteadto employ a top-down traversalorderusingthe . -derivationgraph,the. -edgebetween� � and
� �% would becrucial,asthequantifierintroducestheargumentneededby
thepreposition.Also asabove, . -edgescouldproduceotherinterpretations.
(4.38)find’(m, c) J lose’(m,j) JÅ0 ’(find’(m, c), as’(a’(result-of’(z, that’[[x � ]] � à ), lose’(m,j)))
As shown in Figure4.39and(4.39), if the internalargumentof result is hidden,we canrep-
resentresultsyntacticallyusingtheatomicNP tree,andrepresentits hiddenargumentonly in the
semantics.Figure4.65 shows the derived andderivation trees, . -derivation graphandsemantics
thatresultfrom adjoining� � to ��<�!�'5C�@ , substitutingtheresultinto
� �8 , adjoiningtheresultto �����'! ,substitutingtheresultinto
�;:, andadjoiningtheresultto �����6��� . Thisleadsto thesemanticsin (4.40).
(4.39)Mike foundno new clients.As a result,helosthis job.
NP
result
qM : ß y[result’(y, [[x � ]] � à )]—————————–arg: –
Figure4.64:DLTAG ElementaryTreeandSemanticRepresentationfor ��<�!�45*�@ in (4.39)
D 5� � � � � ���� ������D 5�����6�7� 0 D 5� � � �����
PP� � ����P
as
NPÏ ÏÐÐDET
a
NP
result
D 5�B�&��'!�����6�7��;:
(0)�����'! (3)� �% (0)��<�!�'5C�& (1.2)� � (0)
l � : find’(m, c), l ç : lose’(m,j), l M : as’(a’(ß y[result’(y, [[x � ]] ��à )](z)), l ç ), l g : 0 (l � , l M )————————————————————————————————-arg: –
Figure4.65:DLTAG DerivedandDerivationTrees,. -DerivationGraphandSemanticsfor (4.39)
(4.40)find’(m, c) J lose’(m,j) JÅ0 ’(find’(m, c), as’(a’(result’(z,[[x � ]] � à )), lose’(m,j)))
210
![Page 228: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/228.jpg)
Now, we have shown how bottom-uptraversalof theDLTAG derivationtreeyieldsa singlese-
manticinterpretationfor theabove examples,ascomparedto the . -derivation graph,which would
yield multiple additionalinterpretationsof eachexample. The next issueto addressconcernex-
ampleswherewe may want somesemanticambiguity, to seeif it can be achieved via flexible
compositionin theDLTAG derivationtree.
Recall that discourseadverbialsdo not composewith their left argument, and, becausethe
sentence-level parseis retainedat the discourselevel, the interpretationof the right argumentof
discourseadverbialsis alwaysthe interpretationof the S they modify. Recall further that, in the
two-sentencediscoursescontaininga structuralconnective anda discourseadverbial thatwe have
sofarconsidered,bottom-uptraversalof thederivationtreealwaysyieldsthestructuralconnective’s
secondargumentastheinterpretationof thesecondsentencemodifiedby thediscourseadverbial.
Do we ever want, for example,an interpretationwherethe structuralconnective’s secondar-
gumentis insteadthe interpretationof the unmodifiedsecondsentence?[WJSK03] identify four
separatecasesconcerningthe interactionof therelationsuppliedby a discourseadverbialwith the
relationsuppliedby a structuralconnective. Case1 representsdiscoursesin which thetwo connec-
tivesareinterpretedaseachsupplyinganindependentrelationto thediscourse.Theexamplethey
usewaspresentedin Section4.3asanexampleof how discourseadverbialsallow crossingdepen-
dencies,andis repeatedbelow in (4.16). As alreadynoted,thediscourseadverbial thenrelatesthe
orderingsituationdescribedin b. to thediscoveringsituationdescribedin d., which itself precedes
(temporally)the cancelingsituationdescribedin c. The structuralconnective becauserelatesthe
cancelingsituationdescribedin c. to thediscoveringsituationdescribedin d.
(4.16)
a. JohnlovesBarolo.
b. Soheorderedthreecasesof the’97.
c. But hehadto canceltheorder
d. becausethenhediscoveredhewasbroke.
ContrastCase1 with Case2, which representsdiscourseswherethe relationsuppliedby the
discourseadverbial is interpretedastheright semanticargumentof thestructuralconnective. The
exampleof this caseusedin [WJSK03] is shown in (4.41). In this case,the interpretationcanbe
211
![Page 229: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/229.jpg)
paraphrasedasIf the light is red,stop,becauseif the light is redandyoudo somethingother than
stop,you’ll geta ticket: [WJSK03]arguethattheleft argumentof otherwiseis theinferredsituation
wherethelight is redandyoudo somethingotherthanstop25.
(4.41)
a. If thelight is red,
b. stop
c. becauseotherwiseyou’ll geta ticket.
If in Case1 theright argumentof becauseis theunmodifiedclausein (4.16d), andin Case2
the right argumentof becauseis the modifiedclausein (4.41c), thenthe DLTAG derivation tree
canonly accountfor thesedifferentinterpretationsby varyingthetraversalorder, suchthatCase2
is achievedvia bottom-uptraversal,andCase1 is achievedvia top-down traversal.Allowing both
traversalsintroducessemanticambiguity into our analysesof all the examplesaddressedin this
sectionthat containa structuralconnective anda discourseadverbial, suchthat the interpretation
producedby a top-down traversalyieldstwo separaterelationsconveyed,andabottom-uptraversal
yields the discourseadverbial’s relation embeddedin the structuralconnective’s relation. Note
however thatsuchambiguityis still lessthanthatallowedby . -edges.As illustration,thederivation
treeand . -derivationgraphfor (4.41)areshown in Figure4.66.��12!�34��5�'!� � � � ����������� (1)� � ������<�!�� (1) � ' "� ¿ (3)
� F�!' (3)� �� "��!'<��$�"'! (0)
�B12!#3'��5*#!� � � � ���������"� (1)� � ������<�!#� (1) � 4 "� ¿ (3)
� F�!# (3)� �� "��!#<��A�"#! (0)
Figure4.66:DLTAG DerivationTreeand . -DerivationGraphfor Example(4.41)
Cases3 and4 correspondin somesenseto theoppositeof Case2. Case3 representsdiscourses
wherethe relation suppliedby a discourseadverbial to the secondsentenceis parasitic on the
relation that the structuralconnective suppliesbetweenthe first and secondsentence,and Case
4 concernscaseswherethe relationsuppliedby the structuralconnective is incorporatedinto the
semanticsof thediscourseadverbialasa defeasiblerule. We focusbelow on Case3; Case4 would
behandledsimilarly. An exampleof Case3 ([WJSK03])is shown in (4.42).
25See[WJSK03,KKW01b, KKW01a] for detaileddiscussionof thelexical semanticsof otherwise.
212
![Page 230: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/230.jpg)
(4.42)Johnjustbroke his arm.So,for example, hecan’t cycle to work now.
Theinterpretationof thisexampleis thatJohnnotbeingableto cycle to work is oneexampleof
theresultof Johnbreakinghis arm. In otherwords,theleft argumentof for exampleis dependent
on the relation suppliedby the structuralconnective so betweenthe first and secondsentences.
[WJSK03] arguethat theinterpretationof for exampleinvolvesfirst abstractingthemeaningof the
left argumentwith respectto thethemeaningof theunit it modifies,andthenmakinganassertion
with respectto this abstraction.In their terms,if ª representstheinterpretationof hecan’t cycleto
work now, � representstheinterpretationof Johnjust broke his arm, andresult(� , ª ) representsthe
interpretationof the relationsosuppliesto thesearguments,thenthe interpretationof for example
is asin (4.43),whereexemplifyrepresentstherelationfor examplesupplies.
(4.43)exemplify ( ª , ß X. result(X, � ))
Interestingly, [WJSK03]arguethattheinterpretationof for examplethusresemblestheinterpre-
tationof aquantifier, in thatthescopeof its interpretationis wider thanis explainedby its syntactic
position. In otherwords,our semanticanalysisshouldtake into accountthe fact that in order to
interpretfor example, we appearto alwaysabstractthe interpretationof precedingpredicate.Note
thatalthugh[WJSK03] don’t give for exampleananalysisthatfollowsfrom its internalpredicatear-
gumentstructureandsemantics(i.e.,hiddenargument),but rathertreatit asanunanalysedlexeme,
theirapproachis compatiblewith ananalysisthattakesits internalpredicateargumentstructureand
semanticsinto account.
In order to understand[WJSK03]’s treatmentof for exampleas a quantifier, we must back-
track andexamine[JKR03, Kal02, KJ99]’s accountof Englishquantifiers,which we have so far
overlooked. Above we discussedhow prior analysesof Frenchquantifiersas NP-adjunctsled
[Kal02] to proposederiving semanticinterpretationsfrom the . -derivation graph,ratherthan the
derivation tree. In English,however, quantifiershave beenanalysedasboth NP adjuncts(auxil-
iary trees)andasNPsinto which genericnounssubstitute(initial trees)26. [JKR03, Kal02, KJ99]
addressthe treatmentof Englishquantifiersasinitial trees,andanalysethemashaving a “scope”
and “predicate-argument” part, which they representusing multi-componentTAGs (MC-TAGs).
26see[Kal02] for references.
213
![Page 231: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/231.jpg)
Briefly, eachquantifieris associatedwith two elementarytrees:oneauxiliary treeconsistingof a
singlenoderepresentingthescopepartof thesemanticsof thequantifier, andoneinitial treerep-
resentingthepredicateargumentpart. Thesetreesareshown respectively asthefirst two treesin
Figure4.67,alongwith their semanticrepresentations.Thescopepart (shown first), introducesa
proposition(l g ) containingthequantifier, holesfor its restrictive (hg ) andnuclear(h� ) scope,andits
variable(sM ), which is assertedto bein thenuclearscopeof thequantifier(sM � h� ). Thepredicate
argumentpartintroducesaproposition(l � ) containingapredicatevariable(pM ); thispropositionis in
therestrictive scopeof thequantifier(l � � hg ). After� !#=�!'<�9 adjoinsto therootof �B12��<��� , sM obtains
thevaluel M . After �B����F substitutesinto � !#=�!'<�9 , pM obtainsthevalueq M . After � !#=�!'<�9 substitutesinto�B12��<��� , x M obtainsthevalue � . Theonly possibledisambiguationof holesis then:hM K l g , hg K l � ,h� K l M , which leadsto thesemantics:every’(x,dog’(x), bark’(x)).
SÌ NP÷ ÷øøQ
every
NË N
dog
SÖ Ö××NPË VP
V
barks� !#=�!'<�9 � !#=�!#<�9 �����#F �B12��<���l g : every’(x, hg , h� )sM�� h�——————–arg: sM
l � : p M (x)l ��� hg—————arg: Û p M , (2) t q M : dog’
———–arg: –
l M : bark’(xM )l M�� hM——————arg: Û x M , (1) t
Figure4.67:ElementaryLTAG TreesandSemanticRepresentationsof� !#=�!#<�9 , � !#=�!#<�9 , �B����F , � 12��<���
Now, aswe saw above, when[Kal02] analysesthesemanticsof Frenchquantifers,sheargues
thatMC-TAGs(e.g. associatingquantifierswith two treesto accountfor their scope)shouldn’t be
used,becauseFrenchquantifiersareusuallytreatedasNP-adjuncts,andin orderfor theirscopepart
to adjoin to S, non tree-localMC-TAGs would be required. Becausean unrestricteduseof non-
tree-localMC-TAGshasbeenshown to bemuchmorepowerful thanTAG,sheproposesinsteadthe. -derivation graph,which is closein power to TAG. On theotherhand,in [JKR03] analternative
approachis taken,usingflexible compositionin combinationwith a restricteduseof non-tree-local
214
![Page 232: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/232.jpg)
MC-TAGs (e.g. only adjunctionof the scopepart of quantifiersis allowed to be non-tree-local),
whichdoesnoteffect thegenerative capacityof thegrammar.
Thesyntacticandsemanticanalysisof NP quantifersis not at issuehere;what is at issueis the
syntacticandsemanticanalysisof discourseadverbialssuchas for example. We have illustrated
theuseof MC-TAGsfor Englishquantifersbecause[WJSK03] extendthisanalysisto for example.
As notedabove, [WJSK03]arguethatfor examplebehaveslike aquantifer, in thatits interpretation
musttakescopeoveraprecedingpredicate,whichit abstracts.They suggestthatfor examplecanbe
associatedwith theMC-TAG in Figure4.68,consistingof two auxiliary trees.They arguethat the
secondauxiliary treeshown in thefigure(thepredicateargumentpart)adjoinsto therootof theS it
modifies,while thefirst auxiliary treeshown in thefigure(thescopepart)adjoinsto theroot of the
higherdiscourseunit. For example,this treewouldadjointo therootof thesotreein thederivation
of example(4.42).
D 5 Ì D 5� � ����for example D 5 Ì
Figure4.68:ElementaryDLTAG Treesfor Examplefor example
In fact, it seemsnaturalconsiderhow [WJSK03]’s analysisof scopeeffects in for example
extendsto the interpretationof all discourseadverbialswhoseinternalargumentsaremodifiedby
quantifiersor aregeneric,includingan example, a result,everycasein asan example, asa result,
in every case, etc. For example,in (4.44), the scopeeffects of for an examplecanbe analysed
identicallyto for examplein (4.42)above.
(4.44)Johnjustbroke his arm.So,asanexample, hecan’t cycle to work now.
We leave thedetailsof this extensionfor futurework. Notebriefly however that if a top-down
traversalof thederivationtreeis used,then[WJSK03]’sanalysisof for examplewouldrequirenon-
tree-localMC-TAGs,sincethesecondauxiliary treeshown in theabovefigureadjoinsto therootof
oneelementarytree(theS it modifies),andthefirst auxiliary treeadjoinsto theroot of a different
elementarytree(the higherstructuralconnective). On the otherhand,if a bottom-uptraversalof
215
![Page 233: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/233.jpg)
thederivation treeis used,thantree-localMC-TAGsresult. As illustration, thederivation treefor
[WJSK03]’s analysisof for exampleis shown asthe first treein Figure4.69,where� ����<�!���� � ¿ �! M
signifiesthepredicate-argumentpartof theMC-TAG, and� ����<�!���� � ¿ �! g signifiesthescopepartof
the MC-TAG. In a bottom-uptraversal,we canview ��329834�&! ascomposinginto� ���#<�!���� � ¿ �&! M . The
resultis aderivedtreewith ascopepart,bothof whichcomposeinto � #� .Thesecondderivation treeshown in Figure4.69representsananalysisof for examplethat in-
corporatesits internalpredicateargumentstructure.In thiscase,thescope(� !���� � ¿ �! ) andpredicate
argument( ��!���� � ¿ �&! ) partsof anMC-TAG areassociatedwith thegenericNPexample. In this case,
we cannotsimultaneouslyemploy bothtree-localMC-TAGsandbottom-uptraversal.In a bottom-
uptraversal,�B!���� � ¿ �&! and� ���#< compose;theresultingderivedtreemustcomposeinto ��329834�&! . When
theresultcomposesinto � #� , thescopepart,� !���� � ¿ �&! , adjoinsat theroot; this is anon-tree-localuse
of MC-TAGsakin to theanalysisof quantifiersin [JKR03,10], whichdoesnotaffect thegenerative
capacityof the grammar. On the otherhand,flexible compositionallows us to startat any node.
If we first compose��329834�&! into� ����< , thenthe resultcancomposeinto �B!���� � ¿ �&! . Whenthe result
composesinto � #� , thescopepart,� !���� � ¿ �&! adjoinsat theroot; this is a tree-localuseof MC-TAGs.� #�ð ð ð ð ð ð ð ð��ññññññññ�B1E<�����! (1) �B329834�&! (3)� ����<�!���� � ¿ �&! M (0)
� ����<�!���� � ¿ �! g (0)
� '�� � � � � � ������������1E<�����! (1) �B329%3'�&! (3)� ����< (0)��!���� � ¿ �&! (2)
� !���� � ¿ �! (0)
Figure4.69:DerivationTreesfor PPDiscourseAdverbialswith QuantifiedInternalArguments
We endthis sectionwith the commentthat the analysespresentedabove extendto larger dis-
courses,suchasin (4.45),but alsointroduceadditionalconsiderations.We illustratethis with two
possiblederivationtreesthatcanbeproducedfor (4.45),shown in Figure4.70,alongwith apossible
derivedtree.
(4.45)Mary founda job. ThenMike got a raise.Consequentlythey hadenoughmoney to buy
ahouse.
216
![Page 234: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/234.jpg)
In the first derivation tree in Figure 4.70, we show multiple adjunctionat � F�!# . In [Kal02]
multiple adjunctionat a singlenodeis avoidedwhenpossible,ascombiningMC-TAGs with the
unrestricteduseof multiple adjunctionat a singlenodegoesbeyond the power of LTAG. It may
be that in DLTAG too, multiple adjunctionat a singlenodeshouldbe avoided,dependingon the
scopingpossibilitiesof the relationsconveyed by discourseconnectives in discoursescontaining
multiplediscourseconnectives;this is anissuefor futurestudy. In thesecondderivationtreein Fig-
ure4.70,we haveshown adjunctionof� "��!#� 27 to � F�!# andadjunctionof
�;:to� "�C!'� . Notehowever
thatoneinterpretationproducedby boththesederivationtreesis thatMikeandMary having enough
money to buy a houseis a consequenceof Mike gettinga raise.However, anotherinterpretationof
this discoursecouldbethatMike andMary having enoughmoney to buy a houseis a consequence
of both Mike gettinga raiseandMary finding a job. This interpretationhighlightsan additional
possiblederivation treefor this discourse,namelyonein which thesecond� :
, adjoinsto the root
of thefirst�;:
. Thepotentialinteractionbetweentheresolutionof theleft argumentof consequently
andtheadjunctionsiteof thesecond� :
is not yet fully understood.Althoughasdiscussedabove,
[WJSK03] presentthreecasesdescribinghow the relationssuppliedby discourseadverbialsand
structuralconnectivescaninteract,themoregeneralquestionof how theresolutionof theanaphoric
argumentsof discourseconnectivescanberestrictedby thestructuraldescriptionof thediscourse
hasnot yet beenaddressed.In fact,it maywell bethatthis interactionis bestaddressedvia consid-
erationof discoursedeixisresearch,whichhasalreadyshown thattheresolutionof discoursedeixis
interactswith the structuraldescriptionof the discourse(seeChapter2). We will addresssimilar
remainingquestionsin Chapter6.
Thediscussionsabove indicatethatwe maywantto allow someambiguityin theinterpretation
of the substitutionargumentof both the higherand the lower� :
, andwe may want to allow for
someambiguityin theinterpretationsof theleft argumentsof thediscourseadverbialsthen,conse-
quently, but possiblyonly in somecases,andpossiblyonly with respectto their interactionwith the
interpretationof prior structuralrelations.
27Thediscourseadverbial thencanberepresentedstructurallyakin to consequently
217
![Page 235: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/235.jpg)
D 5� � � � � � ����� �������D 5�B���6�7� 0 D 5� � � � � �ÚÚ ������
D 5Ï ÏÐÐADVP
then
D 5� F�!' 0 D 5� � ����
ADVP
consequently
D 5�B����=�!�����6���� :(0)� F�!# (3)� � � ������ "��!'� (0)
�;:(0)���C��=�! (3)� 34���7#!�?#5*!'�� "�@9 (0)
�����6���� :(0)� F�!# (3)� "��!#� (0)�A:(0)�B����=�! (3)� 34���>'!�?�5C!'�� "�@9 (0)
Figure4.70:DLTAG DerivedandDerivationTreesfor (4.32)
4.3.4 Comparison of Approaches
Thegreatpotentialfor ambiguitythatarisesin discourseis duein partto thefactthat thesemantic
typeof all discourseunitsis thesame.Thus,while wehaveshown that[Kal02]’senrichedderivation
structurecan be usedat the discourselevel to yield compositionalsemanticson the DLTAG . -derivationgraph,we’ve alsoshown thatflexible compositionin thederivation treeis likely a more
parsimoniousapproach.However, theconsiderationof morecomplex discoursesis neededbeforea
compositionalsemanticsfor theDLTAG derivationtreeis complete.
All of the approachesto building a syntax-semanticsinterface for discoursethat have been
discussedin this sectionareexploratory, ratherthanconclusive. Nevertheless,theessentialtheory
behindeachis well-defined,enablingtheir similaritiesanddifferencesto becompared.
218
![Page 236: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/236.jpg)
Apart from the definitional inconsistenciesdiscussedabove, [Gar97b]’s approachto building
a syntaxsemanticinterfaceis a viable onethat builds on feature-basedapproachesto aspectsof
compositionalsemanticsthathave alreadybeenproposedat theclauselevel. Gardent’s discourse
grammar(DTAG) is actuallyquitesimilar in many respectsto DLTAG, in thatit usestreesandthe
operationsof substitutionandadjunctionfor combiningthem.
In fact,it appearsthatall of theelementaryR treesthatGardentexemplifiescouldberepresented
asshown in Figure4.71,e.g. with oneexplicit adjunctionandoneexplicit substitutionsite,where
eachnodeis associatedwith thefeaturestructureshown in Figure4.26.
R[]Ö Ö××A[] Ì B[] Ë
Figure4.71:AnotherRepresentationof theR Treein Figure4.26
Of course,this is nota“recursive” structure,becausethefoot androotnodesarenotof thesame
category. Moreover, therearethusno “anaphoric”discourserelationsin Gardent’s grammar, which
[WJSK03] have shown to be necessaryto limit the computationalpower requiredby discourse
structureto thatof a tree-basedgrammar, asdiscussedabove.
Furthermore,[Gar97b]’s approach(DTAG) relies on the definition of discourserelationsas
featurestructures.ThemajordifferencebetweenDTAG andDLTAG, andindeedbetweenDLTAG
andall otherapproachesto discoursestructureand interpretationdiscussedin Chapter2, is that
DLTAG views cuephrasesthemselvesastheanchors of theelementary“relation” treesinvolvedin
theconstructionandinterpretationof thediscoursemodel.Theseanchorshaveapredicateargument
structureandameaningwhichconveys a relationbetweentheirarguments.
While it is likely thatsomeaspectsof discourserelationsarebestmodeledasfeatures,DLTAG
arguesthat basicpredicateargumentrelationsarealso involved. Becauseat its mostbasiclevel,
discourseconnectives arepredicatesin DLTAG, so in DLTAG we would like to make useof the
structuresthatretainpredicate-argumentinformation,whenbuilding compositionalsemantics.Al-
thoughDLTAGhasalreadyarguedthatthestructuresneededatthediscourselevel aremuchsimpler
thanthoseneededat the clause-level [WJ98], our exploratoryextensionof [Kal02]’s approachto
219
![Page 237: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/237.jpg)
DLTAG alreadyappearsto provide morepossibilitiesthanareneededat thediscourselevel; aswe
saw above, for example,many . -edgesmaybevacuous.The[JKR03] approach,basedon traversal
of thederivationtree,appearsto bemoreviablefor DLTAG.
Featuresrecordedin the derived tree could also be employed in DLTAG, however, perhaps
akin to the way they areemployed at the clauselevel in FTAG, e.g. as indicatingconstraintson
propertiesof argumentsandpredicatesthatmustbepresentin orderfor their treesto combinewith
eachother. For example,in FTAG thepresenceof a Û modet feature(presentin elementaryverb
trees)is requiredin theargumentof thethink tree,indicatingthatthisargumentmustbeaclause,not
a subclausalconstituent.Moreover, while predicateargumentaspectsof compositionalsemantics
canbedefinedwith respectto thederivation tree(or . -derivation graph),it might benecessaryto
usea combinationof thederivation treeandthederived treefor anaphorresolution,if thederived
treedefinessomenotionof locality or distancefor anaphorresolution(e.g. the right frontier) that
is not asobvious with thederivation tree. A wholly feature-basedapproach,however, ignoresthe
predicateargumentstructureof connectives,andmoreover might requireanextremelylargesetof
featuresto representtheir idiosyncraticmeanings.In contrast,theassociationof lexical itemswith
treeanchorsmaintainsconsistency with the clauselevel andthe lexicon. However, [Kno96] has
alreadyshown that therelationsimpartedby a wide varietyof cuephrasescanbeviewed in terms
of a limited setof features(althoughthe idiosyncraticmeaningof thesecuesis still lost). DLTAG
semanticscould make useof thesefeatureswhenbuilding compositionalsemanticsbasedon the
derivedtree. Knott’s approachalsolendsitself well to thepossibilityof lexicalizing inferenceand
representingit, oncecomputed,bothstructurallyandsemanticallyasfeaturestructureswithin or in
additionto thefeaturestructuresof the 0 (or otherstructural)connective28.
Otherdifferencesbetweenthe two approachesarelesssignificant. For example,Gardentmo-
tivatesherapproachby thedesirabilityof theincrementalconstructionof discourseinterpretation,
but asshenotes,the ( - -)substitutionoperationalreadypermitssome“lookahead”with respectto
thebuilding of intermediatetrees;fully incrementaltreeconstructionis not possiblein LTAG, nor
is it necessarilydesirable. In addition,both approachespreserve monotonicityin the semantics.
28This suggestionwasoriginally madeby Aravind Joshiin theDLTAG meetingsat theUniversityof Pennsylvania.
220
![Page 238: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/238.jpg)
The derivation treeprovides is oneway of preservingthe monotonicityof compositionalseman-
tics evenwhile allowing nonmonotonicityin thesyntacticstructure,andtheuseof top andbottom
featurestructuresis another. Thus,thetwo approachesarelargely complementary, anda complete
syntax-semanticsinterfacefor DLTAG will likely combineaspectsof bothapproaches.
4.3.5 Summary
In this sectionwe have discussedhow theDLTAG grammarbuilds discoursedirectly on top of the
LTAG clausegrammar. We thendiscusseda syntax-semanticinterfacethathasbeenproposedfor
a discoursegrammar(DTAG) similar to DLTAG, andwe alsodiscussedextensionsto DLTAG of
LTAG interfacespresentedin Section4.2. We thencomparedtheapproaches,andconcludedthat
aspectsof bothwill likely playa role in acompletesyntax-semanticinterfacefor DLTAG.
4.4 DLTAG Annotation Project
Becausein both thediscourselevel andclauselevel parse,only oneof theargumentsof discourse
adverbialscomescompositionally, the othermustbe retrieved from thediscourse.DLTAG views
thisasaproblemof anaphoraresolution.As with otheranaphora,developingalgorithmscapableof
resolvingthemin way that reflectstheir actualdistribution in discourserequiresdevelopinganan-
notatedcorpus.In thissection,wepresentanoverview of theDLTAGannotationprojectanddiscuss
two preliminarystudiesthathave alreadybeenperformedin anticipationof thelargerproject.
4.4.1 Overview of Project
Themainobjective of theDLTAG annotationprojectis to build acorpuswith discourseannotation.
While not a completerepresentationof discoursestructure,this projectaddressesa rich interme-
diate level betweenhigh level discoursestructureandclausestructurethat canbe reliably anno-
tated,namely, the syntaxandsemanticsassociatedwith discourseconnectives. We usethe Penn
Treebankannotatedcorpus,which containsnaturallyoccurringdatafrom a varietyof sources,has
alreadybeenannotatedfor clausestructureandpart-of-speech,andis currentlybeingannotatedfor
221
![Page 239: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/239.jpg)
predicate-argumentstructure.Our annotationschemawill bedesignedto build anadditionallayer
of discourseannotationinto thePennTreebankcorpus,with links to thisclauselevel information.
Discourseannotationwill occurin two stages.First, the DLTAG parser[FMP�
01] is usedto
parsethediscourse,i.e. thestructuralargumentsof eachdiscourseconnective. Thisparsewill incor-
porateany clauselevel annotationthathasalreadybracketedtheS-internalargumentsof structural
connectives.Second,humanannotatorscorrectany errorsin theparse,andaddannotationtagsfor
the anaphoricargumentsof the discourseadverbials. This two-stagestrategy hasalreadyproved
successfulin the clause-level annotationof the PennTreebankcorpuswith respectto minimizing
humaneffort. Oncecomplete,this annotationcanbe used,alongwith thesyntacticandpredicate
argumentannotationalreadyin Treebank,to developanaphoraresolutionalgorithmsfor adverbial
discourseconnectives.It canalsobeusedto trainastatisticalversionof theDLTAG parserto select
themostlikely parsefrom amongthemany possiblestructuralconnections,andit canbeusedfor
furtherresearchanddevelopmentof NLP applications.
In general,preliminarydevelopmentof theDLTAGannotationprojectinvolvesfirst determining
an initial setof discourseconnectivesto beannotated.While it is hopedthateventuallyall lexical
itemsfunctioningaslinks betweenclausalunits will be annotated,initially the projectwill likely
focuson high-frequency connectives. A reliableannotationschemaandannotationguidelineswill
alsobe developed,consistingof a setof annotationtagsandproceduresfor their use. Moreover,
a “semanticframe” will be built for eachconnective, detailing the semanticpropertiesof each
connective andits arguments.In the remainderof this sectionwe discussin moredetail thekinds
of preliminary studiesaddressingtheseissuesthat will be performedfor eachconnective to be
annotatedin theDLTAG annotationproject.
4.4.2 Preliminary Study 1
Thereareat leasttwo typesof preliminarystudiesinvolved in theannotationof discourseconnec-
tivesandtheir arguments.Thefirst typeof studyhasrecentlybeenillustratedin [CFM�
02]. There
arethreegoalsfor this type of study. First, onesimply wantsto investigatethe syntacticproper-
tiesof discourseconnectivesandtheir arguments.In [CFM�
02], ninediscourseconnectiveswere
222
![Page 240: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/240.jpg)
selectedfor study, shown in Table4.1. As shown, threeof the selectedconnectivesconvey a re-
sultativerelation,threeconvey anadditiverelation,andthreeconvey a concessiverelation. Three
differentannotatorseachannotatedseventy-five tokensof oneconnective from eachset.
Table4.1: NineConnectivesStudiedin [CFM�
02]
Resultative Additi ve Concessiveasa result also neverthelessso in addition whereastherefore moreover yet
The annotationschemaconsistedof four annotationtags. First, eachannotatorannotatedthe
boundariesof theleft andrightargumentof eachconnective,usingtheXML tagsÛ ARG t ...Û /ARG tto annotatetheleft argument,and Û CONNt ... Û /CONNt to annotatetheright argumentthatalso
containedthe connective. The remainingannotationtags, illustratedin Table 4.2, were usedto
capturefeaturesthatwould beautomatically-derivable from a parsedcorpus.As shown in thefirst
column,eachannotatorannotatedthesyntactictypeof theleft argumentwith aTYPEtagAs shown
in the secondcolumn,eachannotatoralsoannotatedthe presenceof otherdiscourseconnectives
andpunctuationthatco-occurwith theconnective beingannotated.As shown in thethird column,
eachannotatoralsoannotatedthepositionof thediscourseconnective in thecontainingsentence.
An examplefrom the corpusstudy is shown in (4.46). As shown, the discourseconnective
beingannotatedis asa result. Its left argumentis theprior sentence,thereareno otherdiscourse
connectiveswithin its left or right argumentexcepttheemptyconnective (signaledby theperiod),
andit occurssentence-initially.
(4.46) Û ARG TYPE=MAIN t YourJuly26editorialregardingthepositionof Attorney General
RobertF. Kennedyonprospective taxrelief for DuPontstockholdersis basedonanerroneousstate-
mentof fact Û /ARG t . Û CONNCOMB=PERIODPOS=INITIAL t As a result, yourcriticism of
Attorney GeneralRobertF. KennedyandtheDepartmentof Justicewasinaccurate, unwarranted
andunfair Û /CONNt .
It wasfoundthat featurepercentagesvariedacrossthediscourseconnectives. For example,so
alwaysoccurredsentence-initially, neverthelessoftentook a sub-clausalconstituent(XP) asits left
223
![Page 241: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/241.jpg)
Table4.2: AnnotationTagsfor theNineConnectivesStudiedin [CFM�
02]
TYPE COMB POSITIONMAIN (sentence) PERIOD INITIALMULT (multiplesentences) COMMA MEDIALSUB (subordinateclause) (SEMI-)COLON FINALXP (sub-clausalconstituent) AND/BUT
argument,andtherefore oftentookasubordinateclause(SUB)asits left argument.
Eachof theannotatorsthenannotatedanadditionaltwenty-five tokensof onediscourseconnec-
tive from eachsemanticset: asa result,in addition,andnevertheless. It wasfoundthat the initial
patternsof featurespercentagesremainedstable,indicatingthat theseconnectivesdisplaypatterns
with respectto thesefeaturesthataresystematicenoughto aid in automaticargumentdetection.
Thesecondgoal in this type of studyis to testinter-annotatorreliability with respectto argu-
mentannotation.For [CFM�
02], threeadditionalannotatorseachannotatedthe left argumentof
thosetwenty-fiveadditionaltokensof asa result,in addition,andnevertheless. For thisannotation,
theTYPEtagwasreplacedwith aslightly moregeneralLOC tag,whosepossiblevaluesareshown
in Table4.3.TheLOC tagdefinesthesentence,consistingof amainclauseandany attachedsubor-
dinateor adjoinedclauses,astheminimalatomicunit from which theleft argumentis derived.The
valuesof theLOC tagdistinguishargumentsderived from thesentencecontainingtheconnective
(SS),thesingleprior adjacentsentence(PS),any sequenceof adjacentsentences(PP),or asentence
or sequenceof sentencesnot contiguousto theclausecontainingtheconnective. This tag is more
generalthantheTYPEtagin thatit doesnotaskannotatorsto distinguishsub-clausalor subordinate
clauseconstituents;ontheotherhand,it addstheinformationof whethertheargumentis contiguous
with thesentencecontainingtheconnective. All otherfeatureswereautomaticallyderivablesothe
additionalannotatorsdid notannotatethem.
Table4.4shows theinter-annotatorresults.Thefirst columnindicatesfour-way agreement,e.g.
whereall annotatorslabeledlabeledthe left argumentwith thesameLOC value. As shown, four-
224
![Page 242: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/242.jpg)
Table4.3: LOC TagValues
SS (samesentence) PP (previousadjacentparagraph)PS (previoussentence) NC (non-contiguous)
wayagreementis greaterthan50%in all cases.Thesecondcolumnindicatesthree-way agreement.
Thethird columnindicatesthecasewheretwo annotatorsagreedon oneLOC value,andtheother
two annotatorsagreedon anotherLOC value;thefourth columnindicatesthatonly two annotators
agreedon a LOC value. Adding the first two columnsshows that annotationof the arguments
of theseconnectivescanbedonereliably; majority agreement(three-way or better)is 92%for in
addition, 96%for asa result. and88%for nevertheless.
Table4.4: Inter-AnnotatorAgreement
Connective 4� 4 3� 4 [2,2] � 4 2� 4in addition 76%(19) 16%(4) 4%(1) 4%(1)asa result 84%(21) 12%(3) 4%(1) 0nevertheless 52%(13) 36%(9) 12%(3) 0
The third goal in this type of studyis to seewhat thesourcesof disagreementteachus about
the annotationguidelinesthat will be neededand the sortsof resolutionalgorithmsthat can be
constructedbasedon syntacticpatterns.Oneguidelinewasdevelopedbasedin part on an initial
“exact match” comparisonbetweenthe left argumentboundariesannotatedby eachof the four
annotatorsfor thethreeconnectivesmentionedabove. It wasfoundthat theannotatorswereusing
differentunderlyingassumptionswhendecidingonthesizeandsyntacticform of theleft argument.
For example, (4.47) containsa discourseof the form cause-result-result. One annotatormight
annotateboththecauseandthefirst resultastheleft argumentof asa result, while anotherannotator
might annotateonly thefirst resultastheleft argumentof asa result.
(4.47)[Lee won thelottery. [Sohewashappy]]. As a result, hisbloodpressurewentdown.
This typeof disagreementcanbereducedby theuseof aminimal unit guideline.If annotators
225
![Page 243: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/243.jpg)
areinstructedto annotatetheminimal unit which couldserve astheleft argumentof a connective,
thenmostannotatorswould annotatethe first resultonly in (4.47). The relationbetweenthe first
andsecondsentenceis not lost, for sowill take asits left argumentthefirst sentence,andtake the
secondsentenceasits right argument. Similarly, in (4.48)oneannotatormight annotatejust the
adjective overworkedastheleft argumentof asa result, while anotherannotatormightannotatethe
entireprecedingclause(Leeis overworked).
(4.48)[Johnis [overworked],andasa result, tired.
Whetherthe minimal unit guidelineappliesin this casedependson how “minimal unit” is
defined.If it is definedastheminimal clause, thentheonly optionfor theannotatoris to annotate
the entireprecedingclause. If it is definedasany phrasalconstituent,then the annotatorwould
annotatetheadjective.
(4.48)alsoillustratesa possiblesyntacticresolutionheuristicfor theleft argumentof discourse
adverbials: in all but onecasein this corpusstudy, whena coordinatingconjunctionlinked two
clauses,and the secondclausecontaineda discourseadverbial, the discourseadverbial and the
coordinatingconjunctionbothtook thesameLOC valuefor their left argument.
4.4.3 Preliminary Study 2
Thesecondtypeof preliminarystudyinvolvedin theDLTAG annotationprojectconcernstheiden-
tificationof lexico-syntacticfeaturesthatdistinguishcontextualargumentsof discourseconnectives
from otherdiscourseunitsin thecontext. Suchastudyis currentlybeingpreparedfor thediscourse
adverbial insteadfor [CFM�
03]. In this study, four annotatorseachannotatethe left argumentof
twenty-five different tokensof insteaddrawn from the PennTreebankcorpus,yielding a total of
onehundredannotatedtokens.Again, theXML tags Û ARG t ...Û /ARG t areused.
To retrieve the left (contextual) argument,eachannotatoris instructedto instantiateit as an
explicit nominalizedAO. For example,in (4.49), the bracketedargumentcould be instantiatedas
Insteadof offenders beingreleasedlocally. To ensureinter-annotatorreliability, eachannotatoris
additionallyannotatingonesetof twenty-five tokensthathasbeenannotatedby anotherannotator,
suchthateachsetis annotatedby two annotators.
226
![Page 244: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/244.jpg)
(4.49)Theprisonis abig employer, andpeoplewerereassuredthat Û ARG t no offenderwould
bereleasedlocally Û /ARG t . Instead, they would be releasedfrom theprisonthey hadfirst been
sentto.
Moreover, it hasbeennotedthatthecontextual clauseargumentof insteadoftenhasanegative
subject,object,or verb,or the verb may be modal,asshown in bold-facein (4.49),or, asshown
bold-facedin example(4.50), the left (contextual) clauseargumentmay be embeddedbeneatha
non-factive verb29. What all of thesefeaturesappearto have in commonis that in one way or
anotherthey allow their clauseto be interpretedwith respectto an alternative setof propositions.
Non-factives,for example,do not presupposethetruth of their complementclause;it canbeeither
trueor false.In (4.50),becausetheeventof themtakinga monthin Europein (4.50)is notasserted
to occur, insteadcan,anddoes,assertstheoccurrenceof analternative event(e.g. thembuilding a
dreamhouse).
(4.50)Their broker encouragedthem Û ARG t to take a monthin EuropeÛ /ARG t ; +4W�(Cb�.�jq-they movedto SouthCarolina,wherethey beganbuilding adreamhouseon thebeach.
Eachannotatoris thusalsoannotatingthepresenceof thesefeaturesfor eachof their twenty-five
tokens.In (4.49)-(4.50),notethatthecontextualalternativeclausesdonothave thesefeatures.Each
annotatoris thusalsoannotatingcompetingclausesin the context for thesefeatures,to ascertain
whethertheseandadditionalfeaturesdo in factdistinguishtheleft (contextual)argumentof instead
from othercontextual clauses30.
4.4.4 Future Work
Essentially, thepreliminarystudiesdescribedabove arethesamekinds of studiesalreadydoneat
theclauselevel to determinethepredicateargumentstructuresof verbs.Futurework will include
doing thesetypesof studiesfor all connectives in thecorpus,therebyenablingfurther refinement
of theDLTAG annotationtagsandguidelines.They will alsoenable“semanticframes”,modeled
afterthoseusedin clause-level predicate-argumenttagging(see[KP02]) to beconstructedfor each
29Thesefeatureswereoriginally notedby BonnieWebberin aDLTAG meeting.30Resultsandfurtherdetailsconcerningthis studyis reportedin [CFM Ñ 03].
227
![Page 245: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/245.jpg)
discourseconnective that incorporatetheir predicate-argumentstructure,meaning,any constraints
on theAO interpretationof their arguments,andany lexico-syntacticfeaturesthatdistinguishtheir
argumentfrom alternatives.Thesesemanticframeswill serveasabasicsemanticsfor eachconnec-
tive, to helptheannotatorsdeterminetherelevantsemanticrolesplayedby thecontext aroundthem
in thecorpusdiscourses.
4.5 Conclusion
In this chapter, we focusedon theconstructionof LTAG andDLTAG trees,andthecomputationof
compositionaldiscoursesemanticsfrom thesestructures.Two syntax-semanticinterfacefor LTAG
thathave beenproposedwerepresentedandcompared.We alsodiscusseda syntax-semanticinter-
facethathasbeenproposedfor DTAG, a discoursegrammarsimilar in somerespectsto DLTAG.
Drawing on theseinterfaces,wediscussedhow Chapter3’s discussionof thesemanticmechanisms
underlyingthe predicate-argumentstructureand interpretationof discourseadverbialscanbe in-
corporatedinto a syntax-semanticinterfacefor DLTAG. We also discussedthe resolutionof the
anaphoricargumentsof discourseadverbials,framing this discussionin termsof a large DLTAG
annotationprojectcurrentlyunderway.
228
![Page 246: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/246.jpg)
Chapter 5
Other WaysAdverbials Contrib ute to
DiscourseCoherence
5.1 Intr oduction
Weconcludeour investigationof S-modifyingADVP/PPadverbialsby emphasizingthatwearenot
claiming that it is only dueto their argumentstructureandinterpretationthat adverbialsestablish
or contribute to discoursecoherence.For example,theargumentstructureof theADVP adverbials
actuallyandreallycannotexplainwhy they have beentreatedasdiscourseconnectives(see[KP02,
Kno96]); asdiscussedin Chapter3, theseadverbialstake only oneAO argument:theinterpretation
of themodifiedclause,whosetruth or fact is assertedto beactualor real. Similarly, theargument
resolutionof thePPadverbialsin anycaseand in fact cannotexplain why they have beentreated
asdiscourseconnectives(see[KP02]); asdiscussedin Chapter3, their internalindefiniteor generic
NP argumentsdenoteunspecified(setsof) entities,andarenot in andof themselvesreferential.
In this chapterwe explore other explanationsfor why suchadverbialscan requirediscourse
context for their interpretation;in particular, thosethat involve the interactionof their semantics
with other aspectsof discoursecoherence.In Section5.2 we introduceprosodyas a semantic
mechanismof discoursecoherenceanddiscussprior analysesof (topic) focus. In Section5.3 we
investigatewhat prior researchhascalled the focussensitivityof certainmodifiers,and discuss
229
![Page 247: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/247.jpg)
how focuseffects in both clausalanddiscourse(S-modifying)adverbialscontribute to discourse
coherence.In Section5.4we introduceGriceanimplicatureasanadditionalaspectof meaningthat
arisesfrom theassumptionof discoursecoherenceanddiscusshow prior analyseshave accounted
for it and distinguishedit from the relatednotion of presupposition.In Section5.5 we suggest
how clausalanddiscourse(S-modifying)adverbialscanbeusedto convey implicatures.In Section
5.6 we point to additionalmechanismsthat mustalsobe consideredboth aloneandin relationto
“discourseconnectives”, in orderto constructacompletemodelof discourse.
5.2 Focus
The useof prosodyto convey meaningis a very active areaof currentresearch.Thereareissues
involved in theseanalysesthatarebeyondthescopeof this thesis;in this sectionwe illustratetwo
semanticanalysesof focusthatassumetree-basedgrammarsakin to DLTAG; we alsohighlight an
approachusingcategorial grammarsthatincorporatestheinsightsof boththeseanalyses.[Gar97a]
citesotherapproachesto theanalysisof focus,in particular, [Pul97].
5.2.1 The Phenomena
Theterm focus1 is usedto referto theprosodicemphasizingof partsof utterancesfor communica-
tive purposes.Focusis typically expressedin spoken languageby pitch movement,duration,or
intensityon a syllable(see[Kri , Lad66, Ste00a]). In addition,certainspecificsyntacticconstruc-
tions,suchastheEnglishcleft sentenceshown in (5.1),makeuseof focusto achievecommunicative
effects(see[Pri86]). Hereandbelow weusecapitallettersto markthefocusedphrase,unlessapar-
ticularanalysisemploys adifferentrepresentation.
(5.1) It wasBILL thatsheinvited for dinner.
Therearealsolanguagesthatmake useof specificsyntacticpositions(e.g. thepreverbalfocus
positionin Hungarian),dedicatedparticles(e.g. Quechua),or syntacticmovement(e.g. Catalan),
to achieve thecommunicative effectsof focus([Kri ]).
1Thereis anotheruseof the term focus,which refersto discoursereferentsthat are salientat the currentpoint ofdiscourseandarepotentialantecedentsfor pronouns(see[GS86]).
230
![Page 248: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/248.jpg)
To illustratethediscourseeffectsof focus,considertheexamplesdiscussedby [Roo95a, Gar97a].H QuestionAnswer Congruence
Thequestionsin (5.2) canbeansweredby theanswersin (5.3) non-contrastively (a) or con-
trastively (b), but notby theanswersin (5.4):
(5.2a)Who did Mary invite for dinner?
(5.2b) Did Mary invite Bill or Johnfor dinner?
(5.3a)Mary invited BILL for dinner.
(5.3b) Mary didn’t invite BILL for dinner, but JOHN.
(5.4a)Mary invited Bill for DINNER.
(5.4b) Mary didn’t invite Bill for DINNER, but JOHN.
Theanswersin (5.3)-(5.4)areidenticalexceptfor thepositionof focus.Thepositionof focus
thuscorrelateswith theWH-phraseor disjoinedalternativesin questions.
However, (5.4 b) hasanadditionalcontrastive readingthatMary invited Bill for something
other than dinner; in this casethe contrastive focus on dinner doesnot coincidewith the
positionof theWH-phraseor disjoinedalternatives. See[Kri92] for ananalysisof multiple
focusconstructions.H Reasonsand Counterfactuals
Imaginethat JohnandMary arefriends. Johnfinds out that he will inherit a fortuneif he
marrieswithin the year. He arrangesto marry Mary becausegoing throughthe processof
finding someoneelseto marryis, in his opinion,too time-consuming.
Underthesecircumstances,thesetof sentencesin (5.5)areeasilyacceptedastrue.
(5.5a)ThereasonJohnMARRIED Mary wasto qualify for theinheritance.
(5.5b) ThereasonJohnmarriedMARY wasto avoid a time-consumingprocess.
(5.5c)If Johnhadn’t MARRIED Mary, hemightnothave gottentheinheritance.
231
![Page 249: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/249.jpg)
Thesetof sentences(5.6)aremorelikely perceivedto befalse.
(5.6a)ThereasonJohnmarriedMARY wasto qualify for theinheritance.
(5.6b) ThereasonJohnMARRIED Mary wasto avoid a time-consumingprocess.
(5.6c) If Johnhadn’t marriedMARY, hemight nothave gottentheinheritance.
Again, thesentencesin (5.5)-(5.6)areidenticalexceptfor thepositionof focus.Theposition
of focuscanthusinfluencethetruth-conditionsof reasoningandcounterfactualstatements.H Conversational Implicatur e
ImaginethatMary andJohnjust received their reportcards.Their motherasksMary about
their Economicsgrades. If Mary answerswith (5.7 a), shegives the impressionthat John
barelypassed.If Mary answerswith (5.7b), shegivestheimpressionthatshedid notpass.
(5.7a)Well, JohnPASSED.
(5.7b) Well, JOHNpassed.
Again, the sentencesin (5.7) areidenticalexceptfor the positionof focus. The positionof
focuscanthuseffect theimplicatureswe draw from whatwe say.
5.2.2 Inf ormation-Structur e and Theoriesof Structured Meanings
[Cho76] observedthatfocusedconstituentspatternsyntacticallylikequantifiersandWH-constituents
with respectto crossover phenomena.For example,supposeheM refersto John. Thenwhile (5.8)
hasonly acoreferentialreading,(5.9)hasbothacoreferentialandaboundvariablereading.
(5.8)Weonly expectedthewomanheM lovesto betrayHIM M .(5.9)Weonly expectedHIM M to bebetrayedby thewomanheM loves.
Thecoreferentialreadingis distinguishedasfollows: We expectedJohnto have theproperty:ß x.x is betrayedby thewomanJohnloves.
Theboundvariablereadingis distinguishedasfollows: WeexpectedJohnto have theproperty:ß x.x is betrayedby thewomanx loves.
232
![Page 250: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/250.jpg)
[Cho76] thusproposesthat focusedconstituentsbe analyzedlike WH-constituentsandquan-
tifiers. In otherwords,they mustmove andthey areassignedscopeat the interpretationlevel of
Logical Form (LF), suchthat an emptyvariablein the surfacepositionof the scopingelementis
boundby a lambdaoperatorin thesemanticinterpretation.As notedby [Roo95a], in Chomsky’s
view focushastheforceof anequality, expressedin termsof adefinitedescriptionas“thex is John”.
TheLF for (5.8) is representedasshown in (5.10).
(5.10)We( ÕUÒ only (HIM) ( ÕUÒ expectedthewomanheM lovesto betrayeM ))Chomsky’sboundvariableprinciplethenaccountsfor thecrossovereffectsin (5.9),by allowing
two LFs,shown in (5.11a)-(5.11b). Chomsky’s boundvariableprinciple is asfollows: At LF, the
phonologicalcontentof a pronounmaybeoptionallydeletedif it is c-commandedby a co-indexed
emptyvariable.
(5.11a) LF: We( Õ�Ò only (HIM) ( ÕUÒ expectedeM to bebetrayedby thewomanheM loves))
(5.11b) LF: We( Õ�Ò only (HIM) ( ÕUÒ expectedeM to bebetrayedby thewomaneM loves))
A problemfor thisanalysisis thatfocusmovementin Englishis notgovernedby generalmove-
mentconstraints.In particular, it canviolate islandconstraints,asshown (5.12),which cannotbe
violatedby WH-constituentsor quantifiermovement,asshown (5.13)-(5.14)[Gar97a, Roo85].
(5.12)They investigated[thequestionof whetheryouknow thewomanwhochairedTHE ZON-
ING BOARD]
(5.13)*(Which board)M did they investigate[thequestionof whetheryouknow thewomanwho
chairedeM ?]
(5.14) *They investigated[the questionof whetheryou know the womanwho chairedevery
boardin town] (whereeveryboard in townscopesover thewoman)
In otherresearchcircles,focusis analyzedin termsof anadditionalpartitioningof theclause,al-
thoughthetheoreticalbasisfor thisvariesaccordingto thebackgroundtheoryof theresearcher. For
example,assummarizedby [vH00], [vdG69] introducesthe pair psychological subject-predicate,
viewing psychologyis theultimatebasisfor languagestructure,while ThePragueSchool[Fir64]
usesthetermstheme-rhemeandtopic-comment, which arebothborrowedfrom traditionalrhetoric
233
![Page 251: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/251.jpg)
andphilology andarere-envisionedby the AmericanStructuralists,who analyzeof focusasex-
pressingwhat is new in an utterance(see[Hal67], [SHP73]). In this view, the questionWhodid
Mary invite for dinner? canbeansweredby Mary invited BILL for dinner becausetheanswerre-
tainsthegiven informationthatMary invited someonefor dinnerandsuppliesthenew information
thatthis personis Bill. Bill is thusaccentedandotherconstituentsarede-accented.[Pri81] argues,
however, thata binarydistinctionbetweenthefamiliarity of informationinadequatelyaccountsfor
numerousdiscoursephenomenaandproposesa five-way taxonomy. [Cho71] and[Jac72] rephrase
thegiven-new distinctionin termsof presupposition-focus, stressingtheir semantic-pragmaticna-
ture. [Jac72] introducesthenotionof focusasa semanticfeature.
Theoriesof “structuredmeanings”[Kri92, vS82] combinethefocusmovementapproachwith
contemporarytheoriesof informationstructure,reformulatingthedistinctionin termsof background-
focus, andproducingasemanticaccountof focussuchthatphrasesdiffering in thelocationof focus
havedifferentsemanticvalues.They assumethatthepresenceof a focusfeaturecausesthefocused
expression(F) to bemovedoutof its originalposition,leaving a traceatLF, which is interpretedas
a variable. Thebackground (B) consistsof the remainderof theclausewith a lambdaabstraction
over thevariableleft by the focus. This backgroundcorrespondsto presupposedinformationthat
is givenor canbeaccommodated,in thecontext, andis alsorelatedto what [Pri86] calls theopen
propositionof anutterance[Ste00a]. Thefocusconstitutesthenew information.
In structuredmeaningtheories,theresultof aclausewith asinglefocusis astructuredmeaning:
a pair consistingof 1) aproperty(B) obtainedby abstractingthefocusedposition,2) thesemantics
of thefocusedphrase.Thepropertyin (5.15a), for example,is thepropertyof beingintroducedby
Johnto Sue,and � is theindividual denotedby Bill , yielding thestructuredmeaningin (5.15b).
(5.15a) JohnintroducedBILL to Sue.
(5.15b) ( ß x.[introduce(j,x,s)],b)
Thepropertyin (5.16a) is thepropertyof beinganx suchthatJohnintroducedBill to x, and (is theindividual denotedby Sue, yielding thestructuredmeaningshown in (5.16b).
(5.16a) JohnintroducedBill to SUE.
(5.16b) ( ß x.[introduce(j,b,x)],s)
234
![Page 252: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/252.jpg)
5.2.3 Alter nativeSemantics
Alternativesemantics[Roo85, Roo92, Roo95a] alsoseeksto producea semanticaccountof focus
suchthat phrasesdiffering in the locationof focushave differentsemanticvalues. However this
theoryreliesonaslightly differentinterpretationof focusthanthepartitioningeffect representedin
structuredmeaningtheories,andconsequentlyproducesawholly semanticanalysisof thephenom-
ena,which is performedin situwithoutany notionof focusmovement.
Accordingto evoking alternativepropositionsis the generalfunction of focus. For example,
a questionlike Who did Mary invite for dinner? asksfor answersof the form Mary invited X
for dinner, whereX variesover persons.The answer, Mary invited BILL for dinner, identifiesa
particularanswerof thisform. Focusonanexpressionis viewedasmarkingthefactthatalternatives
to this expressionareunderconsideration2.
Thustheuseof focusin alternative semanticsis viewednot asdistinguishingtwo partsof the
clause(focusandbackground),but ratherasa semanticfeaturethat triggersthecomputationof an
additionalsemanticvaluefor theentireclause:analternativeset, of which theordinarysemantic
value is a subset.During the interpretationprocess,the focus is left in situ, andthe alternatives
that are generatedfrom the focusedexpressionto yield additionalsemanticvalue arecomputed
wholly semantically. Thenotionof alternativesetshasbeenemployedin avarietyof otherresearch,
including[Bie01, KKW01b, Ste00a].
As shown in(5.17)-(5.18),the focus featureon eachfocusedexpression� , indicatedas � � ,
triggerstheassignmentof bothanordinarysemanticvalue[[.]] � , anda focussemanticvalue[[.]] � :thesetof semanticobjectsobtainablefrom theordinarysemanticvalueby makingasubstitutionin
thepositioncorrespondingto � � .
(5.17)[[mary� likessue]]� = like(m,s)0 D , whereD is thedomainof truth values.
(5.18)[[mary� likessue]]� = like(x,s)for all x 0 D � , whereD � is thedomainof individuals.
More generally, focussemanticvalueis definedrecursively asshown in (5.19),where � rep-
resentsthemeaningof a lexical item, � is thesemantictype of � , and ± ( � M ,...,� � ) representsthe
meaningof acomplex phrasesuchasaclauseor complex verbphrase.
2[SCTÑ 94] useeye-trackingtechniquesto observe theconstructionof alternative setsduringsentenceprocessing.
235
![Page 253: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/253.jpg)
(5.19)
a. [[ � � ]] � = D � ,
b. [[ � ]] � = � [[ � ]] � �c. [[ ± ( � M ,...,� � )]] � = ��± (x M ,...,x� ) ¬ x � 0 [[ � � ]] � �
As shown in (5.19a), thefocussemanticvalueof a focusedlexical item � is thesetof semantic
objectsof samesemantictypeas � . As shown in (5.19b), thefocussemanticvalueof anon-focused
lexical item is the singletonset of its ordinarysemanticvalue. As shown in (5.19 c), the focus
semanticvalueof a complex phraseis computedcompositionallyfrom the focussemanticvalues
of its componentlexical items.Thusin (5.18)above, ± ( � M ,...,� � ) would representtheproposition
Mary� likesSue, andits focussemanticvaluewould bethesetof propositionsof the form x likes
Sue, wherex rangesover individuals.
Restrictivealternative semantics[Roo92, Roo95a] hasbeenintroducedto handlecaseswhere
thealternative setthatis usedin theinterpretationof focusis asubsetof thefocussemanticvalueof
aproposition.In restrictivealternativesemantics,� is usedto representthisalternativeset,denoting
a syntacticallycovert (or Vy+#-`-/.�W ) freesemanticvariable,which focusevokesin a presuppositional
way. Whenfocus is used,the focusfeatureis interpretedby the focus interpretationoperator, ˜,
whichconstrainsC andtherebyhandlestheinterpretationof focusasdefinedin (5.20).
(5.20)Where � is asyntacticphraseandC is asyntacticallycovert semanticvariable,� ˜ C introducesthepresuppositionthatC is asubsetof [[ � ]] � containing[[ � ]] � andat
leastoneotherelement.
Like otherfreevariables,C mustfind a referent.Focusinterpretationcontributesa constraint,
but doesnot fix this referentuniquely. In eachspecificcase,C is identifiedwith somesemanticor
pragmaticobjectthatis presentfor independentreasons.Identifying thevariablewith theappropri-
ateobjectis amatterof anaphoraresolution[Roo95a].
In casesof question-answercongruence,an antecedentfor C is introducedby the semantics
and/orpragmaticsof questions:if we view the ordinarysemanticvalueof a questionasa setof
possibleanswers,i.e. a setof propositionscorrespondingto potentialanswers,bothtrueandfalse,
thentheantecedentfor C canbetheordinarysemanticvalueof thequestionitself.
236
![Page 254: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/254.jpg)
For example,theordinarysemanticvalueof thequestionDoesEvawant teaor coffee?, is the
setcontainingthe propositionsEva wantstea andEva wantscoffee. If the answeris Eva wants
coffee� , thentheconstraintintroducedby ˜ is thatC bea setof propositionsof theform Evawants
y containingat leastEvawantscoffeeandsomethingelse.If theanswerinsteadhadfocuson Eva,
theconstraintwould bethatC is a setof propositionsof theform x wantscoffee. However, in this
lattercase,C wouldbeinconsistentwith theinformationindependentlycontributedby thequestion.
5.2.4 Backgroundsor Alter natives?
Conceptually, a major differencebetweenthe structuredmeaningand alternative semanticsap-
proachesis the distinctionbetweena background(or themeor presupposition)anda setof alter-
natives. The dialoguein (5.21) motivatesthe view that focus usepartitionsthe clauseinto the
background,which expressesgiven information(expressedin thequestion),andthe focus,which
givesnew information(Fred).(5.22)and(5.23)motivatetheview thatfocusyieldstheconstruction
of alternative sets.In (5.22)thereis no prior context at all; thefocusedexpressionis understoodto
expresssomecontrastto otherpossiblereferents.In (5.23),thesecontrastingreferentsareexplicit.
(5.21)Speaker A: Who did Samtalk to?
Speaker B: Samtalkedto FRED.(5.22)Samtalkedto FRED.
(5.23)Speaker A: DoesEdawantteaor coffee?
Speaker B: EdawantsCOFFEE.
Both thestructuredmeaningapproachandthealternative semanticsapproachprovide a single
analysisof the above examples. In truth, we would like both analyses,focus-backgroundandal-
ternative sets,to play a role in a completetheoryof focusinterpretation.As evidenceof this [Kri ]
presentsthedialoguein (5.24).
(5.24)Speaker A: My carbroke down.
Speaker B: Whatdid youdo?�
cananswerwith (1) I calleda mechanicor with (2) I fixedit. If focusexpressesnewness,(1)
shouldhave focuson calleda mechanic, and(2) shouldhave focusjuston fixed, asthecar (i.e. the
referentof it) is given. The lack of accenton it shows thatgivennessplaysa role in accentuation;
237
![Page 255: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/255.jpg)
pronounsaregenerallynotaccentable[Kri ]. But thesameuseof focuscanalsoindicatethepresence
of alternative actions�
couldhave takenwhenheanswerswith either(1) or (2). Onewould like to
representall of this information.
As [Kri] notes,theprocessingpower requiredfor theconstructionof (context-dependent)alter-
native setsmaymake (restrictive) alternative semanticsapproacheslesseconomicalthanstructured
meaningapproaches,especiallyfor casesin whichmultiple foci areinvolved,asin (5.25).
(5.25)Mary only invited BILL for dinner. Shealsoonly invited BILL g for LUNCH M .[Roo95a] however givesa detailedcomparisonof structuredmeaningandalternative semantic
approaches,concludingthattheprosandconsof eachtheoryarenearlyequallybalanced.
For our purposes,oneaspectof this differencebetweenthesetwo theoriesis mostsignificant.
Structuredmeaningapproachesform the backgroundby treatingthe focus featureasa semantic
operator, which mustscopeover a boundvariable,forming anabstractedproperty, or background
(or presuppositionor openproposition),which is thenappliedto the focusedphrase.However, in
this semantics,relevantvariationsin therangeof entitesotherthanthefocusedentitiy to which the
propertycanapplyarenot distinguished.For example,in (5.16a), thebackgroundis theproperty
of JohnintroducingBill to someone. Therelevant rangeof peopleotherthanSuethatJohncould
have introducedBill to is notdistinguishedfrom thesetof all individuals.
The equivalent of this abstractedpropertyin alternative semanticapproachesis the focusse-
manticvalueof aclause,i.e. analternative setof propositionsproducedby substitutingalternatives
in thepositioncorrespondingto the focusedphrase.Again, the relevant alternativesthat couldbe
substitutedfor the focusedphrasearenot distinguishedfrom thesetof all individuals. Restrictive
alternative semantics,however, employs a freevariableC whosereferenceto a relevantalternative
setin thecontext is fixedvia anaphoraresolution,andis constrainedonly to beasubsetof thefocus
semanticvalueof theclausecontainingthe focusedphrase.Thus,restrictive alternative semantic
approachesallow therangeof alternativesto thefocusedphraseto bedependentonthecontext. We
will returnto this dependency anddemonstrateits effectsonS-modifiersin Section5.3.
238
![Page 256: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/256.jpg)
5.2.5 ContrastiveThemes
[Ste00a] makesuseof bothpartitionsandalternative setsin hiscombinatorialgrammar-basedanal-
ysisof focus,theaimof which is to produceaviableaccountof thesyntax-phonologyinterface.In
particular, [Ste00a] retainsboththeme-rhemeandfocus-backgroundpartitions,while incorporating
thenotionof “contextually-relevant” alternative sets.
In Steedman’s analysis,the intonationpatternsof an utteranceestablisha themeanda rheme.
Essentially, the L+H* LH% tune (amongothers)is associatedwith a theme,and the H* LL%
tune(amongothers)is associatedwith a rheme3. His theme-rhemedistinctioncorrespondsroughly
to the focus-backgrounddistinctionsin structuredmeaningtheories:themesconvey presupposed
information that is given in the prior context or canbe accomodated,while rhemesconvey new
information.Steedman,however, representstheinformationpresupposedby a themein termsof an
alternative setof propositionsinstantiatedby differentpossiblerhemesdependingon the context,
whichhecallsa “rhemealternative set”.
Moreover, in his analysis,the intonationpatternsusedto establishthemesand rhemesmay
additionallyconvey that thereis givenandnew informationwithin both the themeandtherheme,
which hecallsbackgroundandfocus, respectively. In otherwords,within both themeandrheme,
focusedphrasescanbeusedto distinguishthemfrom otheralternativesin thecontext. (5.26)from
[Ste00a]) providesanexample.
(5.26)
Q: I know thatMarcellikesthemanwhowrotethemusical.But whodoesheADMIRE?
A:
Marcel ADMIRES thewomanwho DIRECTED themusical.
L+H* LH% H* LL%
background focus background focus background
�.............theme..............
� �..............................rheme................................
�
Boundariesof thethemeandtherhemeof theanswerin (5.26)areindicatedby arrows; within
3Steedmanemploys [PH90]’s tunenotations;anexpositionon prosodictunerepresentationanddistinctionwill takeus too far afieldandwill not beundertaken in this thesis;see[Ste00a]for a comprehensive discussionof theparticularintonationpatternsthatcanestablishthemeandrheme.
239
![Page 257: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/257.jpg)
both this themeand this rhemetherearebackgroundand focusconsituentsas indicated. These
partitionsareconveyedby theprosodictunesdistinguishingthecapitalized(focused)phrases.
Thethemeof theanswerin (5.26)presupposesa rhemealternative set,a setof propositionsof
theform MarceladmiredX, whereX is instantiatedby avarietyof individualsmadeavailablein the
context, including themanwho wrote themusicalandotherpeoplerelevant to theperfomanceof
a musical.Therhemebackgroundin (5.26)includesthegiven informationthata musicalis under
discussion,while therhemefocusrestrictstherhemealternative setto oneproposition.
The themein (5.26) is intonationallymarked asalsocontaininga focusandbackground.The
themebackgroundestablishesthe theme,while the themefocuspresupposesa set of alternative
themesof the form Marcel Y’d X, whereX is instantiatedby the rhemeandY is instantiatedby
differentthemefoci in thecontext, including likesandadmires.
Steedman’s analysisenablesanaccountof a varietyof differentwaysin which a themecanbe
established.In particular, a themecanbe contrastive. For example,supposetheanswerin (5.26)
wasMarcel HATESthewomanwhoDIRECTEDthemusical, accompaniedby thesameintonation
patternasin (5.26). In this case,thesamethemealternative set is constructed,but thespeaker at
oneandthesametime recognizedthethemerequiredby thequestionandestablishesanew theme.
5.2.6 Summary
In this sectionwe have presentedthreeanalysesof focusasa semanticmechanismof discourse
coherence.In particular, we have advocatedtheview that theprosodichighlightingof a syntactic
constituentcan causethe sentencein which it is containedto be interpretedwith respectto the
discourse,by invoking analternative setwhosemembersareinterpretedwith repectto thecontext.
In thenext sections,wewill discusshow adverbialsemanticscaninteractwith focussemantics.
5.3 FocusSensitivity of Modifiers
In thissectionweaddresshow analysesof thefocussensitivityof sub-clausalmodifiersextendto one
issuethathasnotbeenwidely addressedin thefocusliterature:theeffectsof focusonS-modifying
ADVP andPPadverbials.
240
![Page 258: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/258.jpg)
5.3.1 FocusParticles
Certainsyntacticexpressionsare “sensitive to focus”, in that their interpretationdependson the
placementof focus,andaresaidto “associatewith focus” [Jac72]. Onegroupof adverbswhose
sensitivity to focushasbeenwidely investigatedarecalled“focusingadverbs”or, morecommonly,
focusparticles. To illustratetheir focussensitivity, we draw on examplesfrom [Roo95a].
Considera situationin whichJohnhasbothreadthebookandsaw themovie “War andPeace”
but hasreadnothingelse.In thesecircumstances,(5.27a) below is false,but (5.27b) is true. Con-
trastthissituationwith onein whichJohnreadboth“WarandPeace”and“Crime andPunishment”,
but saw nomoviesof either. Then(5.27b) is false,but (5.27a) is true.
(5.27a) Johnonly READ WarandPeace.
(5.27b) Johnonly readWAR AND PEACE.
Sincein eachsituation,thevariantsdiffer only in thelocationof focus,focusis viewedashaving
a truth conditionaleffect in thecontext of theadverbonly [Roo95a].
With many otherfocusparticles,theeffect is saidto bepresuppositional[Roo95a]. In (5.28a),
for example,theuseof alsowith focusintroducesa presuppositionthata propositionof the form
John X’d War and Peace, whereX is not read, is true. In (5.28b), the positionof the focushas
changed,yielding a presuppositionthata propositionof theform JohnreadX, whereX is not War
andPeace, is true.
(5.28a) JohnalsoREAD WarandPeace.
(5.28b) JohnalsoreadWAR AND PEACE.
Similarly, in (5.29a), theuseof evenwith focusintroducesa presuppositionthata proposition
of the form John X’d War and Peace, whereX is not read, is true, while (5.29 b) introducesa
presuppositionthata propositionof the form JohnreadX, whereX is not War andPeace, is true.
The useof evenalsoconveys an additionalpresuppositionalongthe lines that thereis something
unexpectedaboutJohn’s readingWar and Peace,wherewhat is unexpectedcorrespondsto the
focusedphrase.
(5.29a) JohnevenREAD WarandPeace.
241
![Page 259: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/259.jpg)
(5.29b) JohnevenreadWAR AND PEACE.
Generally, the differencebetweena presuppositionaland a truth-conditionaleffect of focus
is shown empirically by constructingtwo otherwiseidentical sentenceswhich differ only in the
locationof focus.If a situation(i.e. a prior context) canbeconstructedsuchthatthetwo sentences
have differenttruth valuesgiventhis situation,thenfocushasa truth-conditionaleffect. If no such
situationcanbeconstructed,but insteadthecontext thetwo sentencesseemto requirediffers,then
focushasapresuppositionaleffect ([Roo95a]).
All of the focusparticlesmentionedabove arefurtherclaimedto presupposethe truth of their
containingclause.Whetheror not all of these“presuppositions” aresemanticpresuppositionsis a
matterof somedebate.As notedby [Bie01], for example,[KP79] arguethatthepresuppositionsof
focusparticlesaredueto conventionalimplicature[Gri75] ratherthansemanticpresupposition.We
will discussthedifferencebetweenpresuppositionandimplicaturein Section5.4.
In bothstructuredmeaningandalternative semanticsapproaches,however, thetruthof thecon-
tainingclauseis representedasasemanticpresupposition.In StructuredMeaningapproaches,focus
particlesareviewedasoperatorswhich take thefocusandthebackground,i.e.,a structuredmean-
ing, astheirargument.Themeaningof only, for example,is definedby [Hor69] asin (5.30):
(5.30)only combiningwith thestructuredmeaning(R,� M ...�B� ) yields:
theassertion:e x M ...e x � [R(x M ...x� ) K (x M ...x� ) = ( � M ...��� )]thepresupposition:R(� M ...�B� ) is true.
In (5.31 a), for example,thereis only one focusedphrase:BILL, andso the backgroundof
its structuredmeaningin (5.31 b) is a one-placerelation. Thus the semanticvalueof the clause
shown in (5.31c)- (5.31d) is anassertionthatJohnintroducednobodyotherthanBill to Sue,anda
presuppositionthatJohnintroducedBill to Sue.
(5.31a) Johnonly introducedBILL to Sue.
(5.31b) structuredmeaning:( ß x.[introduce(j,x,s)],b)
(5.31c) assertion:e x[introduce(j,x,s)K (j,x,s)=(j,b,s)]
(5.31d) presupposition:[introduce(j,b,s)presupposed]
242
![Page 260: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/260.jpg)
In (5.32a), therearetwo focusedphrases,andsoR hasa correspondingnumberof arguments.
(5.32a) Johnonly introducedBILL to SUE.
(5.32b) structuredmeaning:( ß x ß y.[introduce(j,x,y)], b,s)
(5.32c) assertion:e xe y[introduce(j,x,y) K (j,x,y)=(j,b,s)]
(5.32d) presupposition:[introduce(j,b,s)]
[Kri92] furtherproposessemanticvalueswithin theStructuredMeaningframework for avariety
of complex focusstructures,includingmultiple focusparticleswith nestedor independentfoci.
In Alternative Semantics,focusparticlesareassigneda lexical semanticvaluewhichquantifies
over propositions.For example,thefocusparticleonly is definedby [Roo85] asin (5.33),wherep
is auniversallyquantifiedpropositionvariable4.
(5.33)only combiningwith aclause± yields:
theassertion:e p[p0 [[ ± ]] � & = p � p = [[ ± ]] � ]In Montague’s intensionallogic,= p is understoodasmeaningthatp is true; = evaluatesa propo-
sition at thecurrentindex, andthereforecombinesthepresuppositionandassertion.
This rule is differentfrom its StructuredMeaningcounterpartin thatthequantificationis at the
level of propositions:no alternative to [[ ± ]] � is bothdistinctfrom [[ ± ]] � andtrue.
As notedin Section5.2, restrictivealternative semanticshasbeenintroducedto handlecases
wherethealternative setthat is usedin theinterpretationof focusis a subsetof thefocussemantic
valueof a proposition.For example,in thesentencebelow, thealternative setconsistsof just three
propositions,ratherthanthefull setof propositionsof the form JohnintroducedX to Sue(i.e. the
full focussemanticvalue).
JohnbroughtTom,Bill, andHarry to theparty, but heonly introducedBill � to Sue.
In restrictive alternative semantics,focus particlesarestill assigneda lexical semanticvalue
which quantifiespropositions;however, their domainof quantificationis no longer the focusse-
manticvalueof the proposition,but insteadis the covert free variable,C introducedby the focus
4The differencebetweenë �"!$# , whosefocussensitivity yields a truth-conditionaleffect, and %&!('�ë and )+*�)+� , whosesensitivity yieldsa presuppostionaleffect,canberepresentedsemanticallyusing , and - .
243
![Page 261: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/261.jpg)
interpretationoperator, whosereferentset of alternative phrasesis fixed by context, constrained
only to beasubsetof thefocussemanticvalueof theproposition.
Thefocusparticleonly is now defined[Roo85] asin (5.34),wherep is a universallyquantified
propositionvariable.
(5.34)only combiningwith aclause± yields:
theassertion:e p[p0 C & = p � p = [[ ± ]] � ]5.3.2 Other FocusSensitiveSub-ClausalModifiers
Although also, only, evenare the mostcommonlystudiedfocusparticles,the literatureyields a
varietyof additionalphrasescategorizedasfocusparticles(see[web, Kon91, QGLS85]). [Kon91]
basestheseinclusionson thefact thatall phrasescategorizedasfocusparticlessharecertainprop-
erties.Syntactically, for example,focusparticlescanoccurin avarietyof positionsin thesentence.
Someexamplesof this positionalvariationareshown in (5.35). As shown, focusparticlesoften
immediatelyprecede(or follow) the focusedphrase,and their felicituous usein other positions
appearsto be dependenton the positionof the focusedphrase.However, the exact natureof this
dependency is still anopenquestion;it varieswith respectto eachlexical itemandis to someextent
dialect-specific.For example,many readerswill find thelast threeexamples(j-l) awkwardor even
infelicituousif evenis replacedwith only, andsomereadersmaypreferevenin theseexamplesto
bereplacedby stressedalso.
(5.35a) EvenJOHNshowedthepaintingto Mary.
(5.35b) JOHNevenshowedthepaintingto Mary.
(5.35c) JohnevenSHOWED thepaintingto Mary.
(5.35d) JohnevenshowedTHE PAINTING to Mary.
(5.35e) Johnevenshowedthepaintingto MARY.
(5.35f) JohnevenSHOWED THE PAINTING to Mary.
(5.35g) JohnshowedevenTHE PAINTING to Mary.
(5.35h) Johnshowedthepaintingevento MARY.
(5.35i) Johnshowedthepaintingto MARY, even.
244
![Page 262: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/262.jpg)
(5.35j) JohnshowedTHE PAINTING to Mary, even.
(5.35k) JohnSHOWED thepaintingto Mary, even.
(5.35l) JOHNshowedthepaintingto Mary, even.
Semantically, focusparticlessharethe propertyof beingeitheradditiveor restrictive(or the
relatedtermsinclusiveor exclusive) with respectto thewaythey associatethepropositioncontaining
the focusedphraseto the other propositionsin the alternative set (or alternatively, the way they
associatethe focusedphrasewith the background).For example,only is restrictive, becauseas
notedin theprior sectionit assertsthat thepropositioncontainingthe focusphraseis theonetrue
propositionin thealternative set. In contrast,evenandalsoareadditive, presupposingat leastone
othertruepropositionin thealternative set.
In addition,focusparticlesmay order(or scale)the presupposedalternatives,andwithin this
ordering,evaluatethepositionof thealternative contianingthefocusedphrase.For example,even
conveys that thealternative propositioncontainingthe focusedphraseis lesslikely thantheother
alternative propositionswithin thealternative set.
On thebasisof suchproperties,[web, Kon91, QGLS85]includea varietyof additionalADVP
andPPin their listsof focusparticles.While many of theselexical itemshavemultiplemeanings,at
leastonecanbereadasadditiveor restrictive with respectto its interactionwith analternative setin
a focusconstruction5. For example,thelexical itemsin (5.36),thoughmorerestrictedpositionally,
arevery similar in meaningto also, andareoftencategorizedasfocusparticles.
(5.36)aswell, in addition,too
It is not surprisingthat theselexical itemsdisplaythesamepresuppositionalsensitivity to fo-
cusasdoesalso, asshown by theexamplesin (5.37). (5.37a) introducesa presuppositionthat a
propositionof theform JohnX’d War andPeace, whereX is not read, is true. (5.37b) introducesa
presuppositionthatapropositionof theform JohnreadX, whereX is notWar andPeace, is true.
(5.37a) JohnREAD WarandPeace,in addition/aswell/too.
(5.37b) JohnreadWAR AND PEACE, in addition/aswell/too.
5See[Kon91] for a discussionof theidiosyncraticmeaningandpositionalvariationsof otherfocusparticles.
245
![Page 263: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/263.jpg)
[Kon91] alsocategorizesthe lexical itemsshown in (5.38)asadditive focusparticles,though
they tooaremorerestrictedpositionally.
(5.38)likewise, similarly, somuch as
Konigarguesthatthefirst two itemsin (5.38)donotinduceanorderingof thesetof alternatives,
asexemplifiedin (5.39),andconvey a meaningakin to, albeit slightly richer than,also. The last
item in (5.38) he treatsakin to even, in that it inducesan orderingof the setof alternatives and
evaluatesthealternative containingthefocuswith respectto thisordering,asexemplifiedin (5.40).
(5.39)JOHN likewise/similarlysaw themovie.
(5.40)I doubtJohnwill somuch asGREETMary.
[QGLS85] distinguishestwo typesof restrictive focus particles. The first type of restrictive
focusparticlesaresimilar in meaningto only, asshown in (5.41).
(5.41)but, exclusively, just,merely, purely, simply, solely
It is thusnot surprisingthattheselexical itemsdisplaythesametruth-conditionalsensitivity to
focusthatonly does,asexemplifiedin (5.42). If Johnboth readthebookandsaw themovie War
andPeacebut hasreadnothingelse,(5.42a) is false,but (5.42b) is true. If JohnreadbothWar and
PeaceandCrimeandPunishment, but saw no moviesof either, thesetruthvaluesarereversed.
(5.42a) Johnbut/just/solelyREAD WarandPeace.
(5.42b) Johnbut/just/solelyreadWAR AND PEACE.
Thesecondset[QGLS85]categorizesasrestrictive focusparticlesareshown in (5.43).
(5.43)at least,chiefly, especially, in particular, largely, mainly, mostly, notably, particularly,
primarily, principally, specifically
[QGLS85, 604] view theselexical items as restrictivebecausethey “restrict the application
of the utterancepredominantlyto the part focused”. In contrast,however, [Kon91] arguesthat
this predominancedoesnot make theselexical items (which he calls particularisers) restrictive,
but ratherindicatesthat they inducean orderingon the alternatives andevaluatethe proposition
containingthefocusedphrasewith respectto thatordering,akin to theadditive focusparticle,even.
246
![Page 264: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/264.jpg)
[Kon91, 96-97] thus arguesthat theselexical items are likely additive particles,and statesthat
they “clearly” presupposethetruth of otherpropositionsin thealternative set.For example,(5.44)
appearsto imply thatotherpeoplebesidesyoungpeoplearealsosusceptibleto peerpressure.
(5.44)YOUNG PEOPLEin particular aresusceptibleto peerpressure.
However, wefind thatthis “additive quality” is notclearlyapparentin all of thelexical itemsin
(5.43).For example,at least, exemplifiedin (5.45),doesnotclearlypresupposethetruthof another
propositionin thealternative set(thatJohnlikesX whereX is not Mary), nor doesit assertthatno
otherpropositionin thesetis true,althoughit doesinduceanorderingof theelementsin thesetand
evaluatethepropositioncontainingthefocusedphrasewith respectto thatordering.
(5.45)Johnat leastlikesMARY.
In Chapter3 (Table72) we saw that many of theseadverbialscanalsomodify S. In their S-
internaluse,they have beencalled“focusparticles”becausetheinterpretationof thealternative set
they presupposeappearsto dependuponthe presenceof focus. Semantically, the alternative set
theseparticlespresupposeis equatedwith thealternative setintroducedby theinterpretationof fo-
cus,whichcontainsthepropositioncontainingthefocusedphraseaswell asalternativepropositions
in which thefocusedphraseis replacedby otherentitiesof like semantictype.
Indeed,S-internalusesof focus particlesin constructionswithout focus have not even been
consideredin much of the literature,which implies that they are infelicituous or at leasthighly
restricted.If suchcasesdoexist, it is notclearhow thealternativesetthey presupposeis interpreted,
becausethereis no alternative setintroducedby focusinterpretationfor it to beequatedwith. Of
course,if the focusparticleis itself focused,it canrefer to a differentsetthanthesetinvoked by
focuson thephraseit modifies,asshown in (5.46).
(5.46i) Speaker A: DoesEvawantteaor coffeeat lunch?
(5.46ii) Speaker B: Sheonly wantsCOFFEEat lunch.
(5.46iii) Speaker B: SheONLY wantsCOFFEEat lunch.
If B answerswith (ii), heis likely answeringthequestionposedby Speaker A. As notedabove,
the questionprovides an antecedentfor the alternative set that the interpretationof the focused
247
![Page 265: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/265.jpg)
elementCOFFEEintroduces,namely, asubsetof thefocussemanticvalueof theclausecontaining
thefocus.This setis equatedwith thealternative setthatonly presupposes.If B answerswith (iii),
however, hemaybothanswerthequestionandsupplyadditional information.For example,B may
indicateby answeringwith (iii) boththatEvawantscoffeeandthatcoffeeis all shewantsfor lunch.
The latter alternative set,introducedby the focusedon only, appearsto includepropositionssuch
asEvaalsowantscoffeeat lunch, which itself presupposes(via also) thatEva is having something
elsefor lunch.
Interestingly, however, not all lexical itemsthatpresupposeanalternative setrequirethepres-
enceof focus to interpretthat alternative set. For example,the alternative phrasesdiscussedin
Chapter3, includingother, such aredefinedin [Bie01, WJSK03] in termsof alternative sets.The
form otherX, for example,refersto the resultof excludinganentity or setof entitiesfrom a con-
textually relevantalternative set.Thus,otherdogs in (5.47)refersto thesetof dogsresultingfrom
excluding oneor moredogsin the discoursecontext from a larger presupposedsetof alternative
dogs.In contrast,such dogsin (5.48)refersto thesetof dogsresultingfrom usingoneor moredogs
in thediscoursecontext asanexampleof apresupposedsetof dogs.
(5.47)Johnlikesotherdogs.
(5.48)Johnlikessuchdogs.
In otherwords,other is a restrictivephrase,akin to only6, andsuch is anadditiveor inclusive
phrase,akinto also, with respectto thewaythey associatethepropositioncontainingthemodifierto
otherpropositionsin thealternative set.However, thenotionof focusis not invoked; thereneednot
bea focusedphrasein theseconstructionsto determinethesetof alternativesunderconsideration.
Onewonderswhy thesephrasesarenot focusparticles,suchthat their interpretationis depen-
denton or at leastsensitive to thepresenceof focus. Focusandfocusparticlescanbepresent,as
exemplifiedby thediscoursein (5.49).
(5.49)BothJohnandMary hateSally’scatsanddogs.But while Mary likesothercatsanddogs,
Johnonly likesotherDOGS.
6As BonnieWebberpointsout,however, other is not exclusive; it canbeadditive, asshown by thefelicity of theuseof aswell in thefollowing discourse:“Mik e only likespoodles,but Johnlikesotherdogsaswell.”
248
![Page 266: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/266.jpg)
In this example,theuseof focuson dogs invokesa setof alternative propositionsof the form
John likesotherX. Theprior context suppliesoneparticularalternative instantiationof X, namely
thecatswhichMary likes.In contrast,theuseof other invokesanalternativesetwhosepropositions
assertthe existenceof alternative dogs7; againthe context suppliessomeparticularalternatives,
namelySally’s dogs.
Onereason,therefore,thatBierner’s alternative phrasesarenot focus-sensitive in thesameway
asthefocusparticlesis thatthesetof alternativesinvokedby theuseof analternative phrasedonot
containany of thesameelementsthatarecontainedin thesetof alternativesthat is invokedby the
useof focusor a focusparticle.
Of course,asshown in (5.50),we canalsofocusother itself.
(5.50)Mike likespoodles.Johnonly likesOTHERdogs.
In this case,the alternative set associatedwith the semanticsof other containspropositions
assertingtheexistenceof contextually relevantdogs(e.g. thepoodlesthatMike likes),andthis set
alsocontainsthe“otherdogs”themselves,e.g.thesubsetof dogsthatresultfrom excludingpoodles
from thesetof all (salient)dogs.In contrast,thealternative setassociatedwith thefocusonother is
thesetof propositionsof theform JohnlikesX dogs, wherevaluesfor X mayincludedeterminers
andquantiferssuchasthis,all, a, some, etc, aswell ascomparativessuchasbigger, smaller, faster,
etc. Thesemanticsof only requiresthattheseotherpropositionsarefalse.
5.3.3 S-Modifying “F ocusParticles”
As notedabove,thelabel“focusparticle”hasbeenappliedto only S-internalusesof focussensitive
modifiers;their sensitivity to focusin their useasS-modifiershasnot beenaddressed.Moreover,
bothstructuredmeaningandalternative semanticsapproacheshave definedthesemanticsof focus
particleswholly in relationto a focusedphrase.However, by definingthesemanticsof focuspar-
ticles in relation to the free variableC (introducedby the focus interpretationoperator)that can
resolve to a context-dependentalternative set,restrictive alternative semanticscanmoreeasilybe
7In Bierner’s semantics,thealternativesarerepresentedaspropositionswhich asserttheexistenceof anentity.
249
![Page 267: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/267.jpg)
extendedto accountfor S-modifying,discourseadverbialusesof theseadverbs8.
Regardlessof the syntacticconstituentto which they adjoin, all of the adverbialsdiscussed
abovepresupposeanalternative setof propositions.Wethustake thepositionadvocatedby [Ern84]
anddiscussedin Chapter3, that ideally thesamesemanticsshouldberetainedfor a givenmodifier
whenever its meaningdoesnot changedespiteits positionalvariability. In other words, instead
of postulating“homonyms”, thesyntacticconsitituentcorrespondingto theexternalargumentin a
givensemanticsshouldsimply beallowedto vary. Notehowever thatmuchlike we saw in Chapter
3 in clause-level adverbialresearch,it is oftenthecasethatfocusparticleresearchers(see[Kon91])
call S-modifyingusesof focusparticles“conjunctive” or “discourseconnective” andexcludethem
from their analysis.
Our positionis neverthelessapplicableto mostof thefocusparticlesdiscussedabove, because,
again,regardlessof the syntacticconstituentthey modify, they presupposean alternative set of
propositions.Somerequirethatat leasttwo membersof thisalternative setbetrue(e.g.even,also),
while othersrequirethat only onememberof this setbe true (e.g. only, solely). Moreover, they
candisplay the samefocussensitivity asS-modifiersthat they do as(S-internal)focusparticles;
however, asS-modifiers,their interpretationis not dependenton thepresenceof a focusedphrase.
Considerexamples(5.51a)-(5.52a),whichcontainno singlefocusedphrase.
(5.51a) TheMetswon theworld series.It evenrainedin Lima.
(5.52a) TheMetswon theworld series.It alsorainedin Lima.
[Roo95b, p.17] cites example(5.51 a) as a “direction for investigation”,suggestingthat its
interpretationindicatesthatit rainingin Lima is moreimprobablethantheMetswinning theworld
series.In Rooth’sview, thisexampleshowsthatthealternativepresupposedbyevenmustbeallowed
to resolve to theinterpretationof theclauseTheMetswontheworld seriesevenin theabsenceof a
focusedphrase.In otherwords,bothpropositionsarecontainedandorderedin somepresupposed
alternative set.
Althoughthefocusparticlesin examples(5.51a)-(5.52a)aresyntacticallyS-internal,semanti-
8This is not to saythat this approachis sufficient, or thatstructuredmeaningapproachescouldnot alsobeextendedto take theseobservationsinto account.
250
![Page 268: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/268.jpg)
cally thesubjectit in theseexamplesis anexpletive,usedin Englishbecauseasubjectmustalways
be presentin declaratives9. Semantically, moreoever, thesefocusparticlesarefunctioningasdis-
courseadverbials,relatingtheAO interpretationof theclausethey modify to theAO interpretation
of a prior clause,by presupposinganalternative setthatcontainsthemboth. In (5.52a), for exam-
ple, thesetpresupposedby alsocanbeinterpretedascontainingtheeventof theMetswinning the
world seriesandthe event of it raining in Lima; the resultinginterpretationof the discoursemay
simply bethata setof eventsoccurred.This sameinterpretationis achieved if also is S-initial and
S-modifying,asshown in (5.52b).
(5.52b) TheMetswon theworld series.Also, it rainedin Lima.
Moreover, as noted in Chapter3, there are 48 naturally occurring instancesof S-initial S-
modifying also foundin our corpus;oneexampleis shown in (5.52c). Again, thereis no apparent
focusedphrase.The setpresupposedby also containsthe performancesof a variety of different
stocks,foundastheabstractobjectinterpretationsof thefour clausesconstitutingthefirst sentence.
Thetwo instancesof S-initial S-modifyingevenin ourcorpusareactuallymis-parsedNP-modifiers,
however, andasearchof theraw datain ourcorpusproducedno examplesof S-finaleven.
(5.52c) Pfizergained1 7/8 to 67 5/8, Schering-Ploughadded2 1/4 to 75 3/4, Eli Lilly rose1
3/8 to 62 1/8andUpjohnfirmed3/4 to 38. Also, SmithKlineBeechamrose1 3/8 to 39 1/2. (WSJ)
Similarly, in (5.51 a), the set presupposedby even can be interpretedas containingordered
improbableevents.AlthoughS-initial S-modifyingusesof evenappearto beinfelicituous,we can
achieve thesameinterpretationin (5.51b) usingS-finalS-modifyingusesof even.
(5.51b) TheMetswon theworld series.It rainedin Lima, even.
If we replaceeven in (5.51 a) with only, as in (5.53 a), we find that we cannotinterpretthe
setpresupposedby only ascontainingboththeeventof theMetswinning theworld seriesandthe
event of it raining in Lima, becausethe semanticsof only assertsthat only onepropositionin its
presupposedalternative setis true.
(5.53a) TheMetswon theworld series.It only rainedin Lima.
9Althoughin speechthis “rule” doesnotalwayshold.
251
![Page 269: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/269.jpg)
The alternative setpresupposedby only in this casecontainsa singleabstractobject. Unless
thespeaker is implicitly denying thetruth of thefirst sentence,its AO interpretationcannotthusbe
includedin thisalternative set.Wemight thereforesimply interpretthisdiscourseasasetof uncon-
nectedevents. Only on suchan interpretationwould simply presupposethat in no otherlocations
did it rain.
On theotherhand,it appearsthat,onanotherinterpretation,only in (5.53a)canmakeuseof an
inferreddiscourserelationbetweenthe two sentenceswhenselectingits contextually relevant set
of alternatives. For example,we might infer a causalrelationbetweenthe two clauses(which we
canalsomake explicit: TheMetswontheworld seriesbecauseit only rainedin Lima.). Thenthe
interpretationof it only rainedin Lima producesthealternative setcontainingall contextually rele-
vant locationswhereit rained,namelyNew York, andassertsthat it did not rain in theselocations,
yielding theinterpretationthattheMetswon theworld seriesbecauseit did not rain in New York.
Notice however thatalthoughonly canappearfelicituously asan S-initial S-modifier, we find
thatadifferent(anddifficult to understand)interpretationresultsin (5.53b).
(5.53b) TheMetswon theworld series.Only, it rainedin Lima.
This peculiarity of S-initial, S-modifying, discourseadverbial usesof only hasnot beenre-
markedonin theliteraturethatwehave investigated.A numberof suchinstancesthataren’t difficult
to understandareneverthelessfoundin ourcorpus,exemplifiedin (5.54).
(5.54a) His realname’s DiMaggio,only we call him Maggiebecausehehasto take tranquiliz-
ers.(Brown)
(5.54c) Theremight have beena pool of cool waterbehindany of thesetree-clumps:only –
therewasnot. It might have rained,any time; only– it did not. (Brown)
Only in all of thesecasesis paraphrasableby exceptthat. Thealternative phraseexceptfor X is
discussedin [Bie01]; exceptis treatedasexcludingX from a setmadeavailablein thecontaining
sentence(e.g. animalsin (5.55a).Thisanalysisextendsnaturallyto thesubordinatingconjunction
exceptthat shown in (5.55b) andto its adverbialcounterpartexceptshown in (5.55c), althoughas
discussedbelow, thequestionof how AOs(and/orrelationsbetweenthem)make availablealterna-
252
![Page 270: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/270.jpg)
tivesetsof AOsis still anopenquestion.
(5.55a) Exceptfor dogs,Mary hatesanimals.
(5.55b) Overall,Mary is ananimal-hater, exceptthatshelovesdogs.
(5.55c) Overall,Mary is ananimal-hater. Exceptshelovesdogs.
It maybepossibleto usethesemanticsof thefocusparticleonly to accountfor its homonymous
usesin (5.54)10. The clearestcasethat supportsthis analysisis (5.54 c), wherethe modalmight
makesavailablea setof alternatives, e.g. it rained, it didn’t rain, andonly assertsthat only one
of thesealternatives is true. As notedin [WJSK03, KKW01b], however, all the ways in which
an alternative setof AOs canbe derived from a sentenceor discourseunit arenot yet known; we
are just beginning to considerAOs as units of interpretationat all. Moreover, it might turn out
that theseusesof only are bestrepresentedas signalling a causalrelation akin to but, with the
additionalfeaturethat the interpretationof themodifiedpropositionis thesinglefactblocking the
normalconsequenceof theinterpretationof thefirst sentence11. To illustratethisanalysis,consider
a modalvariantof (5.53 b), shown below in (5.53c). The interpretationof this discourseis that
the single (relevant) fact blocking the Mets winning the world seriesis the fact that it rainedin
Lima. A completeunderstandingtheidiosyncraticlexical semanticsandresolutionpropertiesof all
discourseadverbials,includingonly, requiresanannotationstudysuchasdescribedin Chapter4.
(5.53c) TheMetsmight/couldhave theworld series.Only, it rainedin Lima.
So far we have notedonly that focus neednot be presenton a particularphrasein clauses
containingdiscourseadverbial usesof “focus particles”,in orderfor their presupposedalternative
setto beinterpreted.Importantly, however, Roothnotesthat thereis a questionof whetherthereis
no focusor whethertheentire clauseis focused(in (5.51a)). Certainly, if oneadvocatesthetheory
of informationstructure,thenthereis aninformationstructureto every sentence,althoughasnoted
in Section5.2ourunderstandingof whichprosodictunesindicatethemeandrhemeis notcomplete,
andmoreover, in many casesinformationstructureis unmarkedprosodically[Ste00a]. For example,
10The analysiswould procedesimilarly to DLTAG’s analysisof otherwise ([WJSK03, KKW01b]) and instead([CFM Ñ 03]).
11This possibilitywassuggestedby BonnieWebber, personalcommunication.
253
![Page 271: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/271.jpg)
asdiscussedin [Ste00a], asentencemaybeall theme,if it repeatsaprior sentence,or all rheme,as
in theanswerto thequestionin (5.56)(from [Ste00a]). In sucha case,therhemealternative setis
thesetof all (contextually relevant)propositions.
(5.56)Guesswhat?Marcell provedCOMPLETENESS!
Whetheror not they aremarkedprosodically, theclausesmodifiedby discourseadverbialuses
of focusparticlesexemplifiedabove couldbeanalysedas“all-rheme”. This in fact is theimpactof
whatRoothconsiders[Roo95a] whenhesaysthattheentireclausemight befocused.
5.3.4 FocusSensivity of S-Modifying Adverbials
However, S-modifyingadverbialscanalsobe sensitive to the presenceof focuson a sub-clausal
phrase. For example,“adverbsof quantification”have beendiscussedin [Roo85] as displaying
sensitivity to focus,asexemplified in (5.57). As Roothnotes,a bankclerk escortinga ballerina
wouldmake (5.57a) false,but not (5.57b). An officerescortingabankclerkwould runmake (5.57
b) false,but not (5.57a).
(5.57a) OFFICERSalwaysescortedballerinas.
(5.57b) OfficersalwaysescortedBALLERINAS.
Althoughthespecificsemanticsfor eachadverbdependsontheadverb(e.g.always,sometimes,
usually, etc.),[Roo85] andsubsequentRoothpapersgenerallyarguethefollowing:H Adverbsof Quantificationdenotea relationbetweensetsof events,andcombinecomposi-
tionally with anS.H TheSwith whichanAdverbof Quantificationcombinesdenotesa temporalabstract,asetof
eventswhichfills thesecondargument(scope)of theadverb.H Thefirst argument(restriction)is a freecontext variableC over setsof events.H Focuscontributesto fixing thevalueof C.
In Rooth’s analysis,the focusinterpretationoperatorconstrainsthealternative set(C) presup-
posedby adverbsof quantificationto be a subsetof the focussemanticvalueof S. In the caseof
254
![Page 272: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/272.jpg)
(5.58a), this valuewill be(5.58b), which Roothcallsa ‘focus closure’,thesetof eventsof Mary
takingsomeoneto themovies12.
(5.58a) Usually, Mary takesJOHNto themovies.
(5.58b) � t ¬¯h y[AT(t, [ ¾ Mary take y to themovies])]�The interpretationof (5.58a) is then: mosteventsof Mary taking someoneto themovies are
eventsof Mary takingJohnto themovies.
Essentially, we expect that all S-modifying adverbials that presupposean alternative set of
propositionswill besensitive to thepresenceof focus,becausethesetpresupposedby theadverbial
andthesetpresupposedby focuswill containat leastoneidenticalobject,namely, theinterpretation
of thesentencebeingmodified. For example,thealternative setsof bothadverbsof quantification
andfocuscontainthe modifiedclause. In contrast,the alternative setpresupposedby alternative
phrasesdoesnot containat leastoneobjectidenticalto anobjectin thesetpresupposedby focus,
andsotheir two setscannotbeequated.
This expectationthatwhentwo setscontainsimilar objectsit will bedifficult to interpretthem
astwo differentsetsis capturedin theAI planningheuristic“useexisting objects”[Sac77], i.e. if
focus interpretationmakes availablean alternative set,we will equateothersimilar presupposed
alternative setsto this setif possible.In fact, this authorhasnot comeup with a casein which, in
thepresenceof focusandanalternative-setpresupposingS-modifier, thetwo setsthey presuppose
arenot in somesortof set-subsetrelation. It appearsthat thesetevoked by themodifier is always
relatedto thesetevokedby focus.For example,consider(5.57c).
(5.58c) Mary is a greatgrandmother. Every Tuesdayshedoessomethingfun with eachgrand-
child. Usually, shetakesJOHNto themovies.
It appearsthatweinterpretthepresupposedsetof eventsassociatedwith usuallynotasthesetof
eventsof Mary takingX to themovies, but rather, eitherasthesetof eventsof Mary doingsomething
fun with hergrandchildJohn(e.g.Mary takesJohnto therecord store, Mary takesJohnto thepark,
etc.), or to thesetof eventsof Mary doingsomethingfun with eachof hergrandchildren(e.g.Mary
12The formulausestheAT operatorfrom tenselogic (see[Dow79]), whosesyntaxis consistentwith theevent logicdiscussedin [Kam79] ([Roo85]).
255
![Page 273: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/273.jpg)
takesSusieto therecord store, Mary takesEvato thepark,etc.). However, it alsoappearsthatwhen
we produceeitherof theseinterpretations,we arealso prosodicallyfocusingmovies, so that this
focusis alsoproducinganalternative setin whichtheentireverbphrasevaries.Furtherstudymight
indicatethat thereis sometailoredcontext in which it is possible,however, to distinguishthe set
presupposedby anadverbialfrom thesetpresupposedby a focusedphrase,without thepresenceof
additionalfocus.
S-modifyingadverbialsthatdon’t presupposealternative setscanalsobesensitive to thepres-
enceof focus. For example,[KKW01a] show that the interpretationof the discourseconnective
althoughis sensitive to thepresenceof focusbecausetheconsequentof thedefeasiblerule it pre-
supposesanddenies(see[Lag98]) will bemadeavailableby the rhemealternative set. For exam-
ple,(5.59a)presupposesanddeniestheexpectationthat in normalcircumstances,if Clydemarries
Bertha,he will inherit somemoney, representedas in (5.59 b). The rhemealternative setof the
mainclauseincludesavarietyof alternatives,includingClydeinheritingall themoney, someof the
money, andnomoney, asexemplifiedin (5.59c).
(5.59a) AlthoughClydemarriedBertha,hedid not inherit aPENNY.
(5.59b) marry(c,b) t inherit(c,money)
(5.59c) ��N inherit(c,money), inherit(c,money), ...�Evaluative S-modifying adverbshave also beenargued([Kri, Kon91]) to be sensitive to the
presenceof focus.As Krifka statesit, (5.60a)presupposesthatthereis somealternativeX suchthat
it would have beenmorefortunatefor Mary to invite X for dinner. (5.60b) presupposesthat there
is somealternative X suchthatit wouldhave beenmorefortunatefor Mary to invite Bill to X.
(5.60a) UnfortunatelyMary invited BILL to dinner.
(5.60b) UnfortunatelyMary invited Bill to DINNER.
This presuppositionshouldnot beattributedto thesemanticsof unfortunately, however; rather,
it arisesdueto the presenceof alternativescreatedby the useof focus. Notice that Krifka states
thepresuppositionas“it wouldhavebeenmorefortunate”if anotheralternativeshadoccurred.In
otherwords,thepresuppositionisn’t presupposedtrue; we have no senseof whetheror not Mary
256
![Page 274: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/274.jpg)
invitedanyoneelseto any othermeal.Thefocussimplymakesthesealternativesavailable.Thefact
thatthesealternativesareperceivedasbeing“more fortunate”arisessimplybecausethealternative
setis interpretednotascontainingpropositionsof theform UnfortunatelyMary invitedX to dinner
andUnfortunatelyMary invited Bill to X, respectively, but rathertheir unmodifiedversions,Mary
invitedX to dinnerandMary invitedBill to X. Thatthealternativesarenotunfortunatefollows; that
they aremorefortunatethansomethingunfortunatealsofollows.
It is not alwaysthecasethatanS-modifieris excludedfrom thepropositionsin analternative
setinvokedby a focusedphrase,however. For example,thesetof alternativescreatedby theuseof
focusin (5.61)appearsto bethesetof alternative actionsJohnmight have takenaftergettingup; in
otherwords,therelationsuppliedby thenbetweenall alternativesandtheprior clauseis maintained.
(5.61)Johngotup. ThenheLEFT.
We seethesameeffect in otherclausaladverbials,including theepistemics,asexemplifiedin
(5.62). Again thesetof alternativescreatedby theuseof focusappearsto bethesetof alternative
propositionsof theform ProbablyI sawX, ratherthanI sawX. In otherwords,therelationsupplied
by probablyto all thealternativesis maintained.
(5.62)ProbablyI saw MARY.
Moreover, it is not thecasethatall evaluative adverbsareintuitively excludedfrom thepropo-
sitionsin thesetof alternatives. For example,it is easyto imaginea situationin which thesetof
alternative propositionsintroducedby focusin (5.63)wouldhave beensimilarly not surprising.
(5.63)Not surprisingly, I saw MARY.
Ontheotherhand,theevaluativeadverbialbymistakeappearsto patternlikeunfortunately. The
alternativesof (5.64)have theform Mary invitedX to dinner, ratherthanBy mistake, Mary invited
X to dinner.
(5.64)By mistake,Mary invited BILL to dinner.
It would beinterestingto studywhetheror not it is predictablefrom themeaningof theadver-
bial whetherthealternativesintroducedby focuswill includetheadverbialor not.
257
![Page 275: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/275.jpg)
More generally, thereis a significantamountof researchon the interactionof focusanddis-
courseconnectives; [KKW01b], for example,discussthe effect of focuson the resolutionof the
anaphoricargumentof otherwise, [Umb02] discussestheeffect of focusin conjunctedclauses,and
[Joh95] discussestheuseof focusin when-clauses.
5.3.5 FocusingS-Modifying Adverbials to Evoke Context
Focuseffectssuchasthosediscussedabovecanalsointeractwith thesemanticsof clausaladverbials
to evoketheprior context. An exampleis shown in (5.65).Following [Ste00a], theclausaladverbial
on December31 is therhemeandrhemefocus,andhis policy will expire is thetheme.This theme
presupposesarhemealternative setof theform X, hispolicyexpires, whereX rangesover temporal
coordinates.Onealternative temporalcoordinatecanbederivedfrom theS Michael’s coursesare
justaboutto end.
(5.65)Q: Michael’s coursesarejustaboutto end.Whenwill his insuranceend?
A: ON DECEMBER31,his policy will expire.
A clausaladverbialcanalsobeathemefocus,asexemplifiedin (5.66).ProsodyonOnFebruary
14 indicatesthe presenceof a themealternative setof the form Y, I’ll be at location X, whereY
rangesover temporalcoordinates.Alternativesarefound in thecontext, including tonight andthe
setof timesquantifiedby oftenin theclauseoftenyoutravel.
(5.66)
Q: Oftenyou travel, andI don’t know if you’ll behomefor dinner. For
example,I know thatyou’ll behometonight,but wherewill yoube
onFEBRUARY 14?
A: ON FEBRUARY 14, I’ ll bein HOUSTON.
A clausaladverbial canalsobea contrastive theme,asexemplifiedin (5.67)-(5.68).In (5.67),
the reply doesnot answerthequestionfully, ratherit assertswhat theansweris likely to be. The
rhemefocus, the movies, suppliesthe answerto what, restrictingthe rhemealternative setof the
form wewill X tomorrow. Thethemefocus,probably, indicatesthepresenceof alternative themes,
namelyanalternative setof propositionsof the form Y, wewill X tomorrow, whereY rangesover
possibleepistemicvalues(e.g.probably, definitely, possibly, etc).
258
![Page 276: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/276.jpg)
(5.67)Q: Whatwill wedo tomorrow?
A: PROBABLY, wewill go to THE MOVIES tomorrow.
Similarly, in (5.68),thereply doesnot answerthequestionfully, ratheranopinionof what the
answershouldbe is asserted.The rhemefocus,flat, restrictsthe presupposedset of alternative
rhemesof theform Congressshoulddecideon a X tax. Thethemefocus,myopinion, indicatesthe
presenceof alternative themesof theform In Y’sopinion,Congressshoulddecideona X tax, where
Y rangesover contextually relevant individuals.
(5.68)
Q: I know whatkind of taxFredthinksCongressshouldimplement,but whatkind
of tax do you think Congressshouldimplement?
A: In MY VIEW, CongressshouldimplementaFLAT tax.
DLTAG (see[FMP�
01, FW02]) hasalreadyarguedthat nowadaysfunctionsasa contrastive
themein examplessuchas(5.69),wherewhat thehusbanddoesnowadayscontrastswith whathe
usedto do,or will do in thefuture.
(5.69)Q: Whatdoesyourhusbanddo?
A: NOWADAYS, hetakescareof thekids..
Furthermore,we find corpusexamples,suchas(5.70),which show thatnowadaysasa theme
cancontrastwith analternative derivedfrom theVP usedto.
(5.70) To write a play, the dramatistusedto draw on his imaginationandknowledgeof life.
Nowadays,all hedraws onsomeoneelse’s book. (simplifiedBROWN example)
[Ste00a]’s analysisof thesyntax-phonologyinterfacemakesuseof a rangeof specificprosodic
tunesthat have beenassociatedwith sub-clausalconstituentswhen they function as themeand
rheme. In orderto studyhow prosodyeffectsthediscoursecoherenceof S-modifyingadverbials,
we mustfirst understandtherangeof intonationpatternsthatcanbeassociatedwith them.[AC74],
for example,studytheappropriateintonationpatternsfor British EnglishS-modifyingadverbs. It
maybethecasethatthereis somespecifictuneassociatedwith all S-initial,S-modifyingadverbials,
dueto their beinglocatedin topic position. Unfortunately, the variety of prosodictheoriesin the
literature(see[PH90])havenotyetyieldedreliableannotationof speechcorpora,makingit difficult
to studyprosodiceffectsbasedon somethingother thanintuition. Moreover, in text corpora,the
259
![Page 277: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/277.jpg)
writer’s prosodicintentionsarelost; interpretationof prosodyrelieswholly on intuition.
In additionto beingfocusedor containingfocusedelements,anotherway which focuseffects
canbeemployedto causea clausaladverbial to evoke context is throughtheuseof a focusparticle
modifier. In our ADVP corpus,approximatelysixty tokensare found in which a focus particle
is modifying an ADVP adverbial, andin our PPcorpus,approximatelyforty tokensarefound in
which a focusparticle is modifying a PPadverbial. In the majority of casesin both corpora,the
focusparticlemodifieris even. Someexamplesareshown in Table5.1.
As shown, someof theseadverbialsarealreadyanaphoricor comparative andsomayalready
dependon abstractobjectsin the discoursecontext for their interpretation. Although, as stated
above, theseexamplesaredrawn from text corporaandit is thusnot possibleto determinetheir
intonationpatterns,that focusparticlesandfocuscancausea clausaladverbial to requirethedis-
coursecontext for its interpretationis exemplifiedin (5.71),usingoneof thetokensfrom Table5.1.
In (5.71),thereis rhemefocusongrandparent, andthemefocusonnormalexperience. Alternatives
to therhemefocusarefoundin thecontext asfriendsandneighbors, while alternativesto thetheme
focusarederivedfrom therelative clausewhoselivesare surroundedbycrime.
(5.71)Childrenwhoselivesaresurroundedby crime may frequentlyfacethedeathof friends
andneighbors.However, even in NORMAL EXPERIENCE,many childrenarelikely to facethe
deathof aGRANDPARENT.
Table5.1: ADVP/PPAdverbialswith FocusParticleModifier
# ADVP Adverbial # PP Adverbial
4 evennow 1 alsounlike Mr.Ruder18 evenso 1 evenatacar’s length3 eventhen 1 evenin normalexperience1 only adecadeago 1 evenin that1 only hoursearlier 1 evenonhis toughconstitution1 evenmoreremarkably 1 evenwithoutdeals
Interestingly, while our corpusrevealsthatfocusparticlesarefrequentlyfoundmodifying sub-
ordinatingconjunctions(e.g.even/onlyif/when), they donotappearto befoundasfrequentlyin our
corpusmodifying themostcommondiscourseadverbialsthattake hiddensemanticarguments.For
260
![Page 278: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/278.jpg)
example,even/onlyasa result/inadditionall soundodd,anddonotappearin ourcorpus.Moreover,
wefind thatthenin (5.72a)cannotbeinterpretedasasequencerelationbetweentheeventinterpre-
tationsof thetwo sentences,akin to after that in (5.72b). It canonly beinterpretedasa discourse
deicticor anaphoricreferenceto the temporalcoordinateof thefirst sentence,akin to at that time
in (5.72c)13. However, evenafter that andevenat that time in (5.72b)-(5.72c) respectively, are
felicitous. A full understandingof how focusparticlescombinewith discourseadverbialsrequires
furtherstudy, andmayturnout to bebestanalyzedusingagradientnotionof processingdifficulty.
(5.72a) Johnwon’t wake up until latein theafternoon.Eventhenhewill eatbreakfast.
(5.72b) Johnwon’t wake up until latein theafternoon.Evenafter that hewill eatbreakfast.
(5.72c) Johnwon’t wake up until latein theafternoon.Evenat that timehewill eatbreakfast.
5.3.6 Summary
In the prior sectionwe presentedanalysesthat addresshow the prosodicfocus on a sub-clausal
constituentcaneffect the interpretationof the sentencecontainingit, causingthat sentenceto be
interpretedwith respectto thediscourse.In thissectionweshowedhow theseanalysesalsoaccount
for “focussensitive” S-internalmodifiers.In theseaccounts,thesemanticsof such”focusparticles”
aredefinedin termsof (e.g. dependenton) thealternative setevoked by thepresenceof prosodic
focus on or in the sub-clausalconstituentmodified by the focus particle. We then investigated
the usesof thesefocus particlesas S-modifiers. We first addressedcaseswherealthoughthere
wasno obviously focusedsub-clausalelement,the S-modifierwasneverthelessinterpretable.It
appearsthatin suchcasesthediscoursecontext suppliesareferentfor theS-modifier’spresupposed
alternative set.We thenaddressedcaseswherebotha ”focus sensitive” S-modifierandsub-clausal
prosodicfocuswerepresentin a clause. Basedon the existenceof thesetwo cases,we suggest
that focus particlesarenot unconditionallydependentfor their interpretationon the presenceof
(sub-clausal)focus. Rather, the focus“sensitivity” of certainmodifiersarisesdueto thesemantic
similarity betweenthe alternative set they presupposeand the alternative set that prosodicfocus
presupposes.Dueto this similarity, whenbothelementsarepresentin a clause,their presupposed
13Thedifferencebetweenthesetwo interpretationof thenis discussedin moredetail in Chapter3.
261
![Page 279: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/279.jpg)
alternative setsdisplaya strongtendency to resolve to thesamecontextual or accommodatedset.
Finally, we investigatedthe effect of focuson S-modifiersthat have not previouly beenclassified
as”focus sensitive”, e.g. that don’t presupposealternative sets. We first presentedprior analyses
of how focuscaneffect the interpretationof somecommondiscourseandclausaladverbials. We
thenillustratedsomewaysthatfocusonor in otherclausalanddiscourseadverbialscaneffect their
interpretedwith respectto thediscoursecontext.
5.4 Implicatur es
As [Hir91] notes,a variety of “meanings”over andabove the literal contentof an utteranceare
conveyed whena speaker uttersa sentence.Classesof suchmeaningshave beendistinguishedin
thelinguisticsliteratureasshown in (5.73).
(5.73)H Entailments:meaningswhichmustalsobetruewhenthesentenceis true(see[ODA93])H Presuppositions:meaningsentailedby boththesentenceandits negation(see[Bea97])H Implicatures:non-truth-functional meanings(see[Gri89])H IllocutionaryForce:speaker’s actvia theutterance(e.g.asserting, promising)(see[Sea69])H PerlocutionaryEffect: effect of the utteranceon hearer(e.g. convincing, inspiring)(see
[Sea69])
As discussedin Chapter3, entailmentis generallyconsideredpartof thetruth-functionalcom-
ponentof utteranceinterpretation.Presuppositionis sometimesequatedwith implicature; thelatter
is the focusof this section;the distinctionwill alsobe discussedin this section. We will return
briefly to illocutionary forceandperlocutionaryeffect in Section5.6.
5.4.1 Gricean Implicatur e
[Gri89] early proposedan influential pragmaticapproachto accountfor the non-truthfunctional
meaningsconveyed by an utterance. He distinguisheswhat is said from what is implicated, as
262
![Page 280: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/280.jpg)
shown in Figure5.1.
Whatis said representscontext-independentmeaningsthatdeterminethetruthconditionsof an
utteranceandcanbeaccountedfor with a truth-functionalsemantics.Whatis implicatedrepresents
non-truth-conditional meanings.
Conventionalimplicaturesaredefinedasmeaningsthatarebothnon-truth-functional andcontext-
independent.Many researchersview themasidenticalto pragmaticpresuppositions;bothwill be
discussedlaterin thissection.
Non-Conventional implicatures, in contrast,are definedas non-truth-functional and context-
dependentmeaningsthatarisein a givencontext dueto thespeaker’s andhearer’s mutualrecogni-
tion of rulesgoverningconversation.While suchmeaningscanbe linkedto non-linguisticcontext
(Non-Linguistic), includingaestheticandculturalknowledge,in thissectionwe focuson thosethat
arelinkedto language(Conversational).
UtteranceInterpretationð ð ð ð ð ð ðñññññññWhatis Said Whatis Implicated� � � � � � ��������
Conventional Non-Conventional� � � � � �������Non-Linguistic Conversational� � � �����
Generalized Particularized
Figure5.1: GriceanFramework
[Gri75, 45] arguesthat a singleCooperative Principle (CP) is known to conversationpartici-
pants:Makeyourconversationalcontribution suchasis required,at thestageatwhich it occurs,by
theacceptedpurposeor directionof thetalk exchangein whichyouareengaged.
[Gri75, 46-47]assertsfour maximswhich furtherspecifyhow theCPis observed:H Maxim of Quantity: Make your contribution as informative as is required(for the current
purposesof theexchange.Do notmake yourcontribution moreinformative thanis required.
263
![Page 281: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/281.jpg)
H Maxim of Quality: Try to make your contribution one that is true. Do not saywhat you
believe to befalse.Do not saythatfor whichyou lackadequateevidence.H Maxim of Manner: Be perspicuous.Avoid obscurityof expression.Avoid ambiguity. Be
brief (avoid unnecessaryprolixity). Be orderly.H Maxim of Relevance:Berelevant.
Gricearguesthatbecausetheserulesarestandardlyfollowedby conversationparticipants,pur-
poselyexploiting themcanconvey additionalmeanings,or conversational implicatures. An oft-
citedexampleof exploiting theMaxim of Quantityis shown by the“letter of recommendation”for
astudentof philosophy, shown in (5.74).
(5.74)DearSir,
Thisstudent’s Englishis grammatical,andhishandwritingis legible.
Yours,...
As [Hir91] notes,it might seemthat themaxim is violated,becausea philosophyrecommen-
dationis generallyexpectedto containa significantnumberof favorablestatementsrelevant to the
student’s skills in philosophy. This letter containsonly two statements,which, thoughfavorable,
arenot very relevant to philosophy. Griceargueshowever that thewriter is in factobeying theCP
andits maxims;the writer conveys by this letter that s/hehassaidasmuchass/hetruthfully can
abouthis/herstudent’s skills in philosophy, i.e. that s/hehasnothingfavorableto sayspecifically
pertainingto theseskills.
Griceviews this asa particularizedconversationalimplicature. Like all conversationalimpli-
catures,it is context dependentbecausechangingthecontext canchangeor remove it; for example,
if thepersonrequestingthe letter hadstatedthat thewriter wasto commentonly on thestudent’s
Englishandhandwriting,theimplicaturewouldnolongerarise.It is particularizedbecausethecon-
text that licensesit is particular or special. In contrast,a generalizedconversationalimplicature,
suchasthatshown (5.75b) whichariseswhenaspeaker asserts(5.75a) (examplefrom [Hor96]), is
still context dependentin thatchangingthecontext canremove or alter it, but is generallylicensed
in the absenceof particularor marked contexts; a particularizedcontext canremove it, suchasa
264
![Page 282: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/282.jpg)
gameof hideandseekin which thespeaker knows thelocationof his wife but doesnotwantto tell
theseeker. In eachcase,however, it is not thepropositionitself thatlicensestheimplicature,but the
CP, its maxims,andthecontext.
(5.75a) My wife is eitherin thekitchenor in thebathroom.
(5.75b) I don’t know for a factthatmy wife is in thekitchen.
In general,Grice argues,speakers obey the CP and its maxims,andrely on the fact that the
hearerknows this in orderto convey conventionalimplicatures.Of course,a speaker maychoose
to lie, therebyviolating theCP andthemaximsby deliberatelymisleadingthe hearer. Moreover,
a speaker may chooseto opt-out of the CP and the maxims,for example,by invoking the Fifth
Amendmentin acourtof law.
It is often difficult to decidepreciselywhich maxim a speaker intendsto invoke to convey a
conversationalimplicature.In (5.76),for example,all of themaximscanberelatedto theinference
of theimplicature.Whenaspeakerutters(5.76b) in answerto thequestionin (5.76a),s/helicenses
the conversationalimplicaturein (5.76 c) by the sharedassumptionbetweenspeaker andhearer
that the speaker is sayingasmuchas(Quantity)s/hecantruthfully (Quality) saythat is relevant
(Relevance)andsheis sayingit in a way thatis not ambiguousor obscure(Manner).For example,
although(5.76b) is entailedif thespeaker hasfour dollars,saying(5.76b) in thatcaseviolatesthe
maximsof QuantityandManner.
(5.76a) Do youhave any money?
(5.76b) I have threedollars.
(5.76c) I don’t have morethanthreedollars.
Therehave beena varietyof attemptsto formalizetheCPandits maxims,aswell asattempts
to categorize conversationalimplicaturesand formalize how they are inferred (see[Hir91] and
referencestherein). Quantity-basedimplicatures,that is, generalizedconversationalimplicatures
which arisedue to the maxim of Quantity, have received a lot of attentionin the literature(see
[Hor96, Gaz79a, Hir91]). [Hir91] calls themscalar implicatures. Shearguesthat the successful
conveyanceof ascalarimplicaturereliesonthespeaker’sandhearer’smutualperceptionof therank-
265
![Page 283: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/283.jpg)
ing of thespeaker’s utterancewith respectto theotherutterancess/hemight have utteredinstead.
Building on earlierwork, her theoryspecifiestheconditionsunderwhich a speaker may licensea
scalarimplicatureandthatahearermusthaveaccessto in orderto interpretthis implicature.In par-
ticular, shecitesa rangeof research(includingherown) which hasshown thatquantifiers,modals,
conjunctions,numerals,definitesand indefinites,spatio-temporalorderings,epistemicverbsand
verbsof incompletion,set/subsetandentity/attribute andgeneralization/specialization relationsas
well asahostof otherformsin naturallanguageentailor otherwiseevoke orderings(linearaswell
ashierarchical)thataspeaker canuseto convey scalarimplicature.
In (5.76)wesaw anexampleof ascalarimplicaturearisingfrom anorderinginducedby theuse
of a cardinal,the numberthree. In the context of the questionposedin In (5.76a),by answering
with (5.76b) theimplicatureconveyedis that threeis anupperboundon theamountof money the
speaker has. The lower valuesarein fact entailed,e.g. if you have threeof something,you also
have two. If thequestionhadinsteadbeen“Can you afford themagazine?”(whereit is mutually
known that themagazinein questioncoststhreedollars),the implicatureconveyed in (5.76b) due
to the maxim of Quantity is that the speaker hasmore thanthreedollars, i.e. that he canafford
themagazinewithout breakinghis wallet. While valuesabove threearenot entailedby theuseof
three, it appearsto evoke theordering;it is generallyacceptedthatmentionof a cardinalW maybe
ambiguousbetweenthereadingexactlyn, at mostn, andat leastn[Hir91].
In (5.77)we seeanexampleof a scalarimplicatureof notall arisingfrom theorderinginduced
by speaker A’s useof the quantifiersome, which speaker B thenquestions,andspeaker A must
correct(examplefrom [Hir91, 84]). Theorderinginducedby quantifierscannothoweverbedefined
aslogical entailment;in logical terms,e x P(x) doesnot entail h xP(x). However, as[Hir91] notes,
while this meansthatuniversallyquantifiedstatementssuchasAll X are Y doesnot entailSomeX
is Y, it canbeassumedthatuniversallyquantifiedstatementssuchasAll of theX likeY arelogically
representedas h xP(x) J¼e x P(x) andsodo entailtheirsomeX counterparts.
(5.77)
A: Well, someof it youcanchargeto yourgrant.
B: Some?
A: Oh,all.
266
![Page 284: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/284.jpg)
In thesameway, however, modifiersthatquantifyoverpersons,placesor times,or thingsinduce
orderingsthataspeaker canuseto implicatethatuppervaluescannotbeassertedtruthfully. For ex-
ample,aspeaker’s useof somebodymayimplicatenoteverybody, andaspeaker’s useof sometimes
mayimplicatenotoften,notusually, notalways.
[Hir91] notesthatunlike quantifierorderings,modalorderingsareentailedin modalsystems,
where,for example,if a propositionis certain,thenit is alsopossible.In (5.78)we seeanexample
of a scalarimplicatureof not certainarisingfrom theorderinginducedby speaker B’s useof the
modalmay, which indicatesthatthepropositionis possible(examplefrom [Hir91, 84]).
(5.78)A: Youwerein theneighbourhoodof thepantryat onetime,wereyounot?
B: I mayhave been.
Hirschberg arguesthatconjunctionsalsoinduceorderingsthat licensescalarimplicatures.We
saw oneexamplein (5.75),hereandin (5.79),[Hir91] arguesthator includesanalternative setof
propositions.By assertingonly oneof thesepropositions,speakerB impliesthatthealternativesare
false(or unknown). This implicaturedoesnot follow logically, (i.e. asan exclusive disjunction),
becausethe speaker could cancelthe implicature(seebelow), e.g. by addingand dinner sounds
goodtoo.
(5.79)A: Do youwantto goout to dinneror seeamovie?
B: A movie soundsgood.
5.4.2 Pragmatic and SemanticPresupposition
As statedabove, [Gri75] definesconventional implicaturesas meaningsthat areboth non-truth-
functionalandcontext-independent; he views them asarisingby virtue of the meaningof some
word or phrasethespeaker hasused.He distinguishedthemfrom conversationalimplicaturesac-
cording to their cancelabilityand detachability. Conversationalimplicaturesare cancelablebut
non-detachable.For example,theimplicatureof theletterof recommendationin (5.74)canbecan-
celedby altering the context or appendingadditionalmaterial(e.g. but I don’t meanto suggest
that...). However it is non-detachable,in that expressingthe literal contentof what is saidusing
differentlexical items(e.g.penmanshipinsteadof handwriting) doesnot remove theimplicature.
267
![Page 285: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/285.jpg)
In contrast,conventional implicaturesare non-cancelableand detachable.For example, the
conventionalimplicaturethat arisesfrom the speaker’s useof but in (5.80 a) is (5.80 b). That it
is non-cancelableis shown by the infelicitousnessof (5.80 c). That it is detachableis shown in
(5.80d); usingand insteadof but suppliesthesametruth-conditionalcontentwhile detachingthe
implicature. Moreover, the truth of what is said in (5.80 a) is not dependenton the truth of the
implicaturein (5.80 b); (5.80 a) is true if and only if Mary is both poor and honest,and false
otherwise.
(5.80a) Mary is poorbut honest.
(5.80b) Thereis somecontrastbetween(Mary’s) poverty and(her)honesty.
(5.80c) *Mary is poor but honest,althoughthere’s no connectionbetween(her) poverty and
(her)honesty.
(5.80d) Mary is poorandhonest.
Griceusesthesamenotionsto distinguishwhathecallssemanticpresupposition.In contrastto
implicature,presuppositionsareneithercancelablenordetachable.For example,thepresupposition
thatarisesin (5.81a) is (5.81b). Thatit is non-cancelableis shown by theinfelicitousnessof (5.81
c). Thatit is non-detachableis shown in (5.81d); usingceasedinsteadof stoppedsuppliesthesame
truth-conditionalcontentandretainsthepresupposition.Moreover, thetruthof whatis saidin (5.81
a) is dependenton the truth of the presuppositionin (5.81b); (5.81a) is true if andonly if (5.81
b) is true(whetherit is truth valueis falseor unknown if (5.81b) is falsevariesdependingon the
semantictheory.
(5.81a) Michaelhasstoppedbeatinghis wife.
(5.81b) Michaelhasbeenbeatinghis wife.
(5.81c) *Michael hasstoppedbeatinghis wife, althoughhenever beatherin thefirst place.
(5.81d) Michaelhasstoppedbeatinghis wife.
Similarly, [Kar73] distinguishsemanticandpragmaticpresupposition.In this view, if the se-
manticpresupposition(s)of asentenceis true,thenit is truewhetherthatsentenceis trueor false.A
pragmaticpresuppositionof asentence,in contrast,mustbeentailedin contextswherethatsentence
268
![Page 286: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/286.jpg)
is felicitously uttered.In [KP79], pragmaticpresuppositionis equatedwith conventionalimplica-
ture,andit is notedthatmany of thelinguistic investigationsin theliteraturethathave invoked the
notionof presuppositionarein factinvoking pragmaticpresuppositions.
Theconfusionover whethersomethingis a semanticor pragmaticpresuppositionhasbeenfre-
quentlydiscussedanddebatedin theliterature,eithergenerally, or with respectto specificlinguistic
expressionsthat trigger them. Somedoubtthat semanticpresuppositionsexist at all, arguing that
presuppositionsdon’t assertrequirementson truth-conditions,but ratheron theappropriatenessof
utterancesin context (see[Bea97, Hor96, Gaz79b, Sta74, KP79,Str59]). [vdS92], ontheotherhand,
hasarguedthat presuppositionalexpressionsarein fact anaphoricexpressions,while [Sim00] ar-
guesthatthepresuppositionsassociatedwith change-of-stateverbs(e.g.startandstop) areactually
conversationalimplicatures.
Someparticularexpressionsto which presuppositionhasbeenattributed areshown in(5.82);
many of thesehave beendiscussedin this thesis.
(5.82)H definite,quantified,anaphoric,comparativeandfactivedescriptions(see[HK98, Bea97, KK70])H focusparticlesandfocus(see[Roo95a])H discourseconnectives(see[Lag98, KKW01b, Ste00b, KP79])H factive, change-of-state,andjudgmentverbs(see[KK70, Bea97])H cleftsandWH-questions(see[Pri86])
In semantictheories,presuppositionis usually definedas a binary relation betweenpairs of
sentences[Bea97]; onesentencemight presupposeanotherin a semantictheoryif the truth of the
secondis apreconditionfor thefirst to betrueor false,asdiscussedabove. Therepresentationof the
presuppositionhasbeenvariouslyhandledin semantictheories,dependingon the trigger andthe
theory;partial functions,hiddenarguments,assignmentfunctionshave all beenemployed for this
purpose,asdiscussedin Chapter3. Standardtestsfor semanticpresuppositionincludeembedding
269
![Page 287: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/287.jpg)
undernegationor modaloperators,anddiscoursecontext tests,althoughthe latter hold for both
typesof presupposition,andthetestsarenotalwaysapplicableor usefulfor agivenexpression.
In pragmatictheories,presuppositionis definedin termsof the attitudesand knowledgeof
languageusers[Bea97], with or without referenceto specificlinguistic forms (e.g. thesentence).
Therepresentationof presuppositionsin pragmatictheoriesmayemploy modaloperatorsexpressing
intention,belief,andmutualbelief,asin [Hir91].
In mosttheoriesof presupposition,thepresupposedmeaningis generallyassumedto beeither
known, foundor inferablefrom thecontext, or accomodatable.
5.4.3 Summary
In this sectionwe have introducedthenotion of conversationalimplicatureasadditionalmeaning
that arisesfrom the speaker’s assumptionthat discourseis coherent.Conversationalimplicatures
areusedby a speaker to convey additionalmeaningover andabove the literal contentof what he
says.We have distinguishedconversationalandconventionalimplicatureaccordingto thenotions
of cancelabilityanddetachability, anddiscussedhow analysesof conventionalimplicatureoverlap
with semanticand pragmatictheoriesof presupposition.In the next section,we discusshow a
speaker canuseS-modifyingadverbialsto convey implicatures.
5.5 UsingS-Modifying Adverbials to Convey Implicatur es
In this sectionwe briefly review how our analysisin this thesishasalreadyinvoked thenotionof
presuppositionwhich existing semantic(or pragmatic)theoriesmustaccountfor. We thenshow
how a speaker’s useof S-modifyingadverbialscanconvey meaningsakin to whatGricehascalled
conversationalimplicatures,whichdiscoursetheorymustalsoaccountfor.
5.5.1 Presupposition
In this thesis,wehaveencounteredavarietyof usesof thetermpresuppositionasasemanticnotion,
anda varietyof semanticrepresentationsfor it, dependingon theenvironmentin which it wasen-
countered.For example,in our ADVP/PPadverbialdataset,we saw that theinternalPPargument
270
![Page 288: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/288.jpg)
or theADJ derivative of theADV canbe(or containelementsthatare)anaphoric,quantified,adef-
inite description,comparative, and/orcontaina hiddenargument.We alsosaw that theadverbials
in our datasetcaninteractwith focus. While we focusedour discussionon how semanticrepre-
sentationsof theselinguistic forms could be extendedto their usewithin S-modifyingadverbials,
therebyaccountingfor thefactthatthey maydependfor their interpretationontheAO interpretation
of non-NPconstituentsin theprior context, we saw above that thedependency of theselinguistic
formson their context canbeviewedaseithera semanticor pragmaticpresupposition.
5.5.2 Conversational Implicatur es
It is not always the casethat the dependency of an S-modifying adverbial on discoursecontext
canbeaccountedfor wholly semantically. For example,asnotedin the introduction,S-modifying
adverbialssuchasactuallyor really take only oneAO argumentsemantically:theinterpretationof
the modifiedclause.As discussedin Chapter3, theseadverbssupplyepistemicfeaturesto the S
they modify. While focuslikely playsa role in their interpretation,conversationalimplicaturecan
alsobeinvolved. A varietyof examplesof S-modifierssimilar in meaningto actuallyareshown in
Table5.2alongwith their corpuscounts.
Table5.2: Higher-OrderedEpistemicAdverbialsYielding Implicatures
Count Adverbial Count Adverbial
31 actually 1 in truth105 in fact 6 really2 in reality 16 surely
In Section5.4we discussedhow modalsinducemodalorderingssuchthata speaker’s useof a
modalcanyield a scalarimplicature.In (5.78), for example,thespeaker’s useof maywasargued
to implicatethat the truth of thepropositionis not certain or not knownto him/her. In (5.83),on
theotherhand,[Hir91] arguesthatby denying theassertionof ahighervaluein themodalordering,
thespeaker conveys thatthelessercanis trueor unknown to him/her. In bothcasesthemodalvalue
involvedin theimplicatureis presentin thecontext (i.e. in A’sutterance).
271
![Page 289: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/289.jpg)
(5.83)A: I would like to know if I cantake off thebackplate.
B: Youshouldn’t have to.
As notedin Section5.4,modalorderingsareentailedin modalsystems;for example,if apropo-
sition is actual,real, sure, or in thesetof facts, thenit is alsopossible, probable, etc. Thus,while
a speaker cannotassertsomethingis actual, real, sure, or in thesetof factsandat thesametime
implicatethata lessermodalvalueof thepropositionsis not known or certainto him/her, we argue
thatthespeakercanusethesehighermodalvaluedS-modifierswhenhebelievesthata lessermodal
valueof thepropositionsis not mutuallyknown or certain.In otherwords,peopledo not normally
assertthat a propositionis true, to do so would violate (at least)the maximsof Quantity(do not
makeyourcontribution moreinformative thatrequired)andManner(bebrief). Thatis, unlessthere
is evidenceindicatingto thespeakeror writer thattheheareror readermaysupposethemodalvalue
of thepropositionto befalseor unknown, or its truth unexpected.Suchevidencemight comefrom
thecontext.
For example,in (5.84), from our corpus,the article writer citesthe quoteasfrom Cervantes.
Thewriter of thereplyappearsto take thisasevidencethatthearticlewriter did notknow thatKing
Solomonis theoriginal source.Theimplicaturearisingby B’s useof actually, thatthetruth of the
modifiedpropositionwasnot mutuallyknown, is however bothcancelable(e.g. if B appends,“but
I bet you alreadyknew that”) andnon-detachable;B cansubstitute,for example,in fact, andstill
achieve thesameimplicature.
(5.84)Your Oct. 2 articleon DanielYankelovich cited thequote“A goodnameis betterthan
greatriches” asbeing from Cervantes’“Don Quixote.” Actually, Cervantesborrowed that quote
from awriter of some25centuriesearlier:Israel’s King Solomonwrotethosewordsin theBookof
Proverbs(22:1). (WSJ)
Theseadverbialscanalsobeusedwhencontext impliesa propositionthat is “hard to believe”,
asin (5.85),alsofrom ourcorpus.
(5.85) CathrynRice could hardly believe her eyes. While giving the Comprehensive Testof
BasicSkills to ninthgradersatGreenville High SchoollastMarch16,shespottedastudentlooking
at crib sheets.Shehadseencheatingbefore,but thesenoteswereuncanny. “A stockbroker is an
272
![Page 290: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/290.jpg)
exampleof ...” Virtually word for word, the notesmatchedquestionsandanswerson the social-
studiessectionof thetestthestudentwastaking. In fact, thestudenthadtheanswersto almostall
of the40 questionsin thatsection.(WSJ)
Furthermore,asin (5.86), theseadverbialscanbe usedto explicitly deny the truth valueof a
propositionthathasbeenassertedby anotherspeaker.
(5.86)A: Youarewrong.
B: Actually/Surely/Really/Infact, I’m notwrong.
Of course,[Hir91]’s analysisof (5.78),wherethespeaker’s useof maycanimplicatethat the
the truth of the propositionis not certain or not known to him/her, can be directly extendedto
S-modifyingadverbialsthat asserta lower valuein the modalordering;thesetoo canbe usedby
a speaker to implicate that a higher value is falseor unknown. Someexamplesof S-modifying
adverbialswhoseinternalargumentis interpretedasa lower-orderedmodalityandcanbeusedfor
thispurposeareshown in Table5.3.
Table5.3: Lower-OrderedEpistemicAdverbialsYielding Implicatures
# Adverbial # Adverbial
4 in asense 1 in onesense4 in away 2 in oneway1 to adegree 2 in certainrespects1 to anextent 5 with few exceptions
The interpretationof theseadverbialsasconveying a modality is due to the interpretationof
their internalargument,asdiscussedin Chapter3. Theirinterpretationasconveying alower-ordered
modality, however is dueto thedeterminersthatmodify theseinternalarguments.[Hir91]’sanalysis
of (5.77)), whereA’s useof the quantifiersomecanyield a scalarimplicaturenot all, thus also
appliesto S-modifyingadverbials,asdoesheranalysisof quantifiersover people,placestimesand
things(e.g.sometimes), andheranalysisof cardinalW yieldingscalarimplicaturesof at mostn or at
leastn or exactlyn. Someexamplesof S-modifyingadverbialscontaininglower-orderedquantifiers
over people,timesandplacesthatcanbeusedto convey suchimplicaturesareshown in Table5.4.
Interestingly, however, it appearsthatPPS-modifyingadverbialscontainingthehigher-ordered
273
![Page 291: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/291.jpg)
quantifiersall or anycanalsobeusedby speakersto convey an implicature. As notedin Section
5.4, in contrastto modalandtemporalorderings,e xP(x) doesnot entail h xP(x). Wearguethatthis
however canbetheimplicaturecausedby theuseof theadverbialsin Table5.5. Corpusexamples
containingadverbialsfrom thefirst columnof Table5.5areshown in (5.90)-(5.89).
Table5.4: Lower-OrderedQuantificationalAdverbialsYielding Implicatures
# Adverbial # Adverbial
7 atonepoint 1 for thosefew6 at times 1 on two occasions10 for amoment 1 to some
Table5.5: Higher-OrderedQuantificationalAdverbialsYielding Implicatures
# Adverbial # Adverbial
24 in any case 9 above all13 in any event 49 afterall6 at any rate 10 anyway
(5.87)Creative accountingis a hallmarkof federalcredit. Many agenciesroll over their debt,
payingoff delinquentloansby issuingnew loans,or convertingdefaultedloanguaranteesinto direct
loans.In anycase, they avoid having to write off theloans.(WSJ)
(5.88) His arm had beengiving him sometrouble and Rectorwas not enoughof a medical
expertto determinewhetherit hadhealedimproperlyor whetherHino wassimply rebellingagainst
thetediouswork in theprint shop,usingthestiffnessin his armasanexcuse.In anyeventRector
senthim to thelocalhospitalto have it checked...(BROWN)
(5.89)Manchester’s unusualinterestin telegraphyhasoftenbeenattributedto thefact that the
Rev. J. D. Wickham,headmasterof Burr andBurton Seminary, wasa personalfriend andcorre-
spondentof the inventor, SamuelF. B. Morse. At anyrate, Manchesterdid not lag far behindthe
first commercialsystemwhichwassetup in 1844betweenBaltimoreandWashington.(BROWN)
As discussedin Chapter3, due to their modificationby all or any, the abstractobjectscase,
event,ratedo notneedto beidentifiedwith setsof abstractobjectsin thecontext. They thusdo not
274
![Page 292: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/292.jpg)
functionsemanticallyasdiscourseconnectives.Wearguethataspeaker’suseof theseadverbialscan
however implicatethatthereis somerelevantabstractobjector setof abstractobjectsin thecontext
whichshouldbeviewedascontainedin thesetsidentifiedwith theseinternalargumentsandwhich
thusshouldberelatedto theAO interpretationof themodifiedpropositionvia theprepositionhead
of the PPadverbial. Our basisfor this argumentis simply that,unlessthereis a relevant abstract
object(or set)underconsideration,peopledo not normallyassertthe relationof a proposition(or
otherabstractobject) to the setof all cases,events,or rates;to do so would violate (at least)the
maxim of Quantity (do not make your contribution more informative that required)andManner
(be brief). In the above examples,the context doescontainsa relevant case, event, rate. Once
an implicated(setof) abstractobjectsin the context is identified,the particularrelationsupplied
by the prepositioncanbe interpreted;of course,in mostcasesthis relationwill be a metaphoric
interpretationof thepreposition,or evenidiosyncraticto theadverbial.However, theseimplicatures
arecancelable,dependingon context, but non-detachable.For example,a speaker could say: “At
any rate,althoughI’m not consideringanything in particularthat we’ve discussedso far”, anda
speaker canusein anyeventandat anyrate interchangeably.
We argue that above all createsthe sameimplicature; by using an adverbial that relatesthe
modifiedpropositionto someunspecifiedsetof all, the speaker implicatesthat somerelevant set
of abstractobjectsis to be found in the context. An examplewherethis is the caseis shown in
(5.90)(therelevantsetincludesall theAOsthatthepresidentdid or did notwant).Of course,above
all doesnot assertthat themodifiedpropositionis physicallyabove all otherrelevantpropositions;
ratherit assertsthat the modifiedpropositionis the most important(above in status)proposition
amongall relevantothers.
(5.90)ThePresidenthadsetfor himselfthetask,whichhebelievedvital, of awakeningtheU.S.
andits allies to the hardandcomplex effort necessaryto shift that balance.He did not want the
effort weakenedby any illusion that summitmagicmight make it unnecessary. He wantedtime,
too, to review theUnitedStates’globalcommitmentsandto testboththepolicieshehadinherited
andnew oneshewasformulating.Aboveall, hedid notwantto appearto berunninghatin handto
PremierKhrushchev’s doorstep.(WSJ)
275
![Page 293: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/293.jpg)
While we arenot attemptingto completelyaccountfor the idiosyncraticmeaningof thesead-
verbials,we do believe theseimplicaturescanbe employed andcanaccountfor onepart of their
interpretation. Note however that it is sometimesdifficult to understandhow the assumptionof
discoursecoherenceyieldsthecontext dependency of a discourseadverbial. For example,while it
may be that thesameimplicaturesarisewhena speaker usestheadverbialsafter all andanyway,
therelationof their linguistic form to their meaningis muchmoreabstract.Considertheexamples
from ourcorpusin (5.91)-(5.92).
(5.91)Thestockmarket’s dizzyinggyrationsduringthepastfew dayshave madea lot of indi-
vidual investorswish they couldbuy somesortof insurance.After all, they won’t soonforget the
stockbargainsthatbecameavailableaftertheOctober1987crash.(WSJ)
(5.92)Therearemany, many thingsto do. Find out what you like to do mostandreally give
it a whirl. If you can’t think of a thing to do, try something– anything. Maybeyou will surprise
yourself.True! Wearenotall greatartists.I, frankly, can’t draw astraightline. Maybeyou arenot
thatgiftedeither, but how aboutputteringaroundwith theold paints?Youmayamazeyourselfand
acquirea realknackfor it. Anyway, I’ ll betyouhave a lot of fun.(BROWN)
As theseexamplesindicate,after all doesn’t assertthatthemodifiedpropositioncomestempo-
rally or textually afterall thatprecededit; rather, it appearsthat in many casesit canbepreceded
by because, andit appearsto indicatethat themodifiedpropositionis amongthemostsignificant,
andalreadyknown, possiblecauses.It may be that after all shouldbe analyzedas taking as its
argument,or implicating,asetof causesarisingfrom aninferredor explicit causalrelationbetween
themodifiedclauseandtheprior discourse.[WJSK03]proposea similar analysisfor for example,
whoseinterpretationappearsto beparasiticonapreviousexplicit or inferredstructuralrelation,but
while for for examplethis relationmaybe oneof cause,result,or elaboration,or suppliedby the
idiosyncraticmeaningof averb,after all seemsto requireacause.
Anywayappearsto indicatesa returnto a discussionthat got off on a tangent. It may be that
anywayshouldbe analyzedas taking as its argument,or implicating, one or more elaborations
arisingfrom an inferredor explicit elaborationrelationbetweenthemodifiedclauseandtheprior
discourse.
276
![Page 294: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/294.jpg)
This discussionis exploratory; while it is clear that the modifiedclausesof theseadverbials
are beingrelatedto theprior discourse,eitherthroughfocus,implicature,idiosyncraticlexical se-
mantics,or somecombinationthereof;in orderto determinewhetheror not it is usefulto consider
their linguistic form andits interactionwith implicaturesascontributing to their interpretation,an
annotationprojectsuchasthatdescribedin Chapter4 is required.
5.5.3 Interaction of Focusand Implicatur e
Thus,wecaninvoke thenotionof conversationalimplicatureto explainwhy S-modifiershavebeen
treatedasdiscourseconnectiveseven thoughtheir linguistic form doesnot causethemto refer to
anabstractobjectin theprior discourse:by usingthemthespeaker hascreatedan implicature. In
many of thecaseswhereimplicaturesarise,therealsoappearsto befocus. It wasnotedin Section
5.2 that focuscaneffect the interpretationsof conversationalimplicatures.[Hir91] alsodiscusses
how intonationcaneffect thedisambiguationof variousimplicatures;for ourpurposes,wenotethat
the two mechanismsof discoursecoherenceinteract;it maybethat to induceanawarenessof the
orderinginvokedby linguistic forms,they mustbefocused.This requiresfurtherstudy, however.
5.5.4 Summary
In this sectionwe have addressedhow S-modifyingadverbialscanbe usedby a speaker to create
conversationalimplicatures,causingthesentencecontainingthemto beinterpretedwith respectto
thediscourse.We have shown that [Hir91]’s analysisof how scalarimplicaturescanarisethrough
the useof lexical itemsthat induceorderingscanbe directly appliedto the useof theseforms in
or asS-modifyingadverbials.We have furtherpostulatedtwo additionaltypesof implicaturesthat
canarisewhenthespeaker’s obeyanceof theCPandits maximsinteractswith therequirementthat
discoursebecoherent.
277
![Page 295: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/295.jpg)
5.6 Other Contrib utions
5.6.1 DiscourseStructure
Many researchershavestudiedthepragmaticeffectsof discourseconnectivesondiscoursestructure
andinterpretation.As discussedin Chapter2, [GS86, Sch87] view many adverbials,andintonation,
ascuesof discoursestructure. For example,anywaymight signala return (pop) to a preceding
segment,while nowmight signaltheembedding(push)of a segment. As discussedin Chapter3,
viewing the interpretationsthata discourseunit makesavailableasabstractobjectsmayenableat
leastsomeof these“pragmatic”usesto beaccountedfor in thesemanticsof theDLTAG model.
5.6.2 Performatives
As notedin Section5.4, thereareothermeaningsassociatedwith utterancesthat have not been
discussedin this thesis;in particular, their illocutionary forceanda perlocutionaryeffect. [Sea69]
associatestheseadditionalmeaningsconveyedby anutterancewith, amongotherthings,intonation
and“performative verbs”, e.g. I promiseyou..., I baptizeyou...,etc. It may be that that the use
of adverbialscanhave a similar forceandeffect, which shouldeventuallybeincorporatedinto the
DLTAG model.
5.7 Conclusion
In this chapterwe have exploredtwo waysapartfrom their predicateargumentstructureandin-
terpretationthat adverbialscan be usedto contribute to discoursecoherence.Our intent was to
demonstratehow prosodicfocusandimplicaturecancauseanadverbialwhich is not normallyde-
pendenton thediscoursefor its interpretationto beinterpretedwith respectto thediscourse.While
our analysiswaspreliminary, it makesthe importantpoint thatadverbial semanticsis not theonly
factorinfluencingthe interpretationof adverbials,andshouldnot beconsideredin isolationasthe
only mechanismcausingadverbialsto creatediscoursecoherence.It is our expectationthatall of
thesefactorswill eventuallyhave to beincorporatedinto acomprehensive modelof discourse.
278
![Page 296: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/296.jpg)
Chapter 6
Conclusion
6.1 Summary
The underlyingthemeof this thesisis that discourseis not a completelyseparatecategory from
syntaxandsemanticsandthatdiscourse-level coherencecanarisefrom thesamesubstrateasclause-
level coherence.
We have overviewedsimilaritiesanddifferencesbetweena varietyof theoriesof discourseco-
herence,which, taken together, distinguishdifferentmodulesrequiredto build a completeinter-
pretationof discourse.We discussedDLTAG ([FMP�
01, CFM�
02, WJSK03, WKJ99, WJSK99,
WJ98]) asa theorythatbridgesthegapbetweenclauseanddiscoursemodules,by usingthesame
syntacticandsemanticmechanismsthatbuild theclauseinterpretationto build anintermediatelevel
of discourseinterpretationon topof theclauseinterpretation.In DLTAG,cuephrases, or discourse
connectives, arepredicates,like verbs,exceptthey cantake interpretationsof clausesasarguments.
For coordinatingandsubordinatingconjunctions,bothargumentscomestructurally. For adverbial
cuephrases,which aremainly adverb (ADVP) andprepositional(PP)phrases,only oneargument
comesstructurally. Basedon considerationof computationaleconomyandbehavioral evidence,
DLTAG arguesthat theotherargumentof theseadverbialsmustberesolved anaphorically. How-
ever, while DLTAG proposesthat certainadverbialsfunctionasdiscourseconnectives,it doesnot
isolatethissubsetfrom thesetof all adverbials.
279
![Page 297: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/297.jpg)
Becausethesetof adverbialsis compositional,andthereforeinfinite ([Kno96]), it is notpossible
to list all of the adverbialsthat function asdiscourseconnectives. We have thereforepresenteda
corpus-basedinvestigationof how semanticsandpragmaticscausecertainadverbialsto beclassified
asdiscourseconnectives,while otherconnectivesarenot. Our investigationhasshown thatin many
casesdiscourseconnectives are not an accidentalgroupingof ADVP and PP adverbials; rather,
their discoursepropertiesarisenaturally from their semantics.We have distinguisheddiscourse
adverbialsandclausaladverbialssemanticallyin termsof their predicateargumentstructureand
interpretation. We have arguedthat whetheror not ADVP and PP adverbialsfound in a corpus
are classifiedas discourseadverbialsdependson the interpretationof their semanticarguments.
We have shown thatdiscourseadverbialsarevery similar to discoursedeixis, in thatboth require
for their interpretationan abstractobjectmadeavailable in the prior discourseor spatio-temporal
context.
Our semanticanalysisis presentedindependentlyof any particularsemanticformalism,partly
becausehow informationis representedin a modeldepends,at leastto someextent,on whatcom-
putationalproblemsthe resultingmodelwill be usedto solve, andwhetherthe expenseof a par-
ticular representationproducesworthwhile results. Neverthelessour resultsmust be taken into
accountwhenbuilding a discoursemodel,for in their entiretythenumberof discourseadverbials
far overshadow the few discourseconnectives that have beenso far addressedin the literature.
We have thusoverviewed a variety of semanticformalismsanda variety of clauseanddiscourse
level syntax-semanticinterfaces. Drawing on this research,we presentedoneway in which the
predicate-argumentstructureandinterpretationof discourseadverbialscanbe incorporatedinto a
syntax-semanticinterfacefor DLTAG. We also discussedthe DLTAG annotationproject, whose
goalis to annotatetheargumentsof all discourseconnectivesin thePennTreebankcorpus.
It is notonly dueto theirargumentstructurethatadverbialsappearto requirediscoursefor their
interpretation,however. Wehave encountereda numberof adverbialsthathave beentreatedasdis-
courseconnectivesdespitethe fact that their discoursesemanticsalonedoesnot causethemto be
interpretedwith respectto abstractobjectinterpretationsin thediscourseor spatio-temporalcontext.
Wethushaveexploredotherexplanationsfor why suchadverbialscanrequirediscoursecontext for
280
![Page 298: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/298.jpg)
their interpretation;in particular, thosethat involve the interactionof their semanticswith other
aspectsof discoursecoherence.We discussedprosodyasa semanticmechanismof discourseco-
herenceandshowedhow focuseffectsin bothclausalanddiscourseadverbialscontributediscourse
coherence.WediscussedGriceanimplicatureasanadditionalaspectof meaningthatarisesfrom the
assumptionof discoursecoherenceandshowedhow clausalanddiscourse(S-modifying)adverbials
canbeusedto convey implicatures.
In summary, we’veshown thatthediscoursesemanticsof adverbialscangoa longwaytowards
building completemodelof discourseinterpretation,but otheraspectsof discoursecoherencemust
alsobetakeninto account,andcorpusannotationandanalysisis alsorequired,to allow usto better
understandtheempiricalrealizationof discoursesyntaxandsemanticsandthecorrespondencesbe-
tweendiscourseconnectivesanddiscourserelations,suchaswhenandwhichdiscourseconnectives
areused,versuswhenandwhichdiscourserelationsareinferred.
6.2 Futur e Dir ections
Weendby identifying anumberof otherissuesfor futurestudythataresuggestedby theinvestiga-
tionsin this thesis.Eachof theseconstitutesabroaderuseof thesyntactic,semanticandpragmatic
functionsof adverbials.
Thefirst line of researchconcernstherepresentation,derivation,andresolutionof abstractob-
ject interpretations.Althoughasstatedabove, how informationis representedin a modeldepends,
at leastin part,on whatcomputationalproblemstheresultingmodelwill beusedto solve,because
DLTAG is built on topof aclause-level module,ideally thesemanticsemployedfor bothdiscourse
deicticreferenceto abstractobjectsandadverbialmodificationof abstractobjectswouldbesimilar.
However, the issueof how to representandderive abstractobject interpretationsis still an open
question.For example,asnotedin Chapter2, the fact that abstractobject interpretationsarenot
grammaticalizedasnounsprior to discoursedeixis reference,andthe fact that thereappearto be
structuralrestrictionsondiscoursedeicticreferenceto themhasleadsomeresearchersto arguethat
abstractobjectsarenotpresentasentitiesin thediscoursemodelprior to discoursedeixisreference.
Accordingto theseresearchers,their entity readingis addedto thediscoursemodelvia discourse
281
![Page 299: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/299.jpg)
deixis reference. [DH95], for example,usetype coercionalongwith other computationaloper-
ationsto accessAO interpretations,while [Web91] usesreferring functions. In contrast,[Sto94]
and[Ash93] argue that AO interpretationsarealreadypresentin the discoursemodelbeforedis-
coursedeixisreferenceto them.[Sto94] usesapossibleworldssemanticsin whichdiscoursedeixis
refersto informationstates,while[Ash93] representseventsashiddenargumentsto verbsandfacts
andpropositionsaspiecesof semanticstructure,both of which canbe the referentsof discourse
deixis. We saw in Chapter3 that [Ern84, Moo93, Ver97, KP79] all make useof the (*j`_a. basic
abstractobjectsin exploring the semanticinterpretationof adverbial modification,althoughonly
[Moo93] formalizesthe representationof theseentities,treatingboth eventsand factsasentities
alreadypresentin thedomainof individuals,andusingpredicatelogic to representsbothashidden
argumentvariablesof theirassociatedpredicates.
Whatall of theseresearchersagreeon is thatAO interpretationsmustbederivablefrom non-NP
constituents.However, thiswork hasonly consideredthequestionin thecontext of discoursedeixis
or a few adverbials,andmoreover only considereda relatively smallnumberof AO interpretations.
In Chapter3 weintroducedadditionalcomplexity into theanalysis,namelythatthepossibleobjects
modifiedby adverbialscorrespondsto a muchwider rangeof objectsthanpreviously considered.
We neverthelessbelieve thatby extendingthe rangeof objectsto beconsidered,thecurrentstudy
may lead to a more comprehensive solution. It may, for example,be the casethat all AOs can
be subsumedwithin [Ash93]’s existing classification;in otherwords, it may be feasibleto treat
all AOs as sub-typesof events, fact-like objects,or proposition-like objects,as [Ash93, Ven67]
begin to do. If this is the case,we could treathiddenargumentsas “place-holders”for abstract
objects,andallow themto becoercedto specificdenotations,suchasconsequencesandreasonsthat
aredependenton anddeterminablefrom thepredicationon them. Theproblemof abstractobject
anaphoraresolutionhasalsobeenfarmorestudiedfor discoursedeixisthanfor discourseadverbials.
Fully understandingboththemechanismsthatdeterminewhichelementsareaccessibleto function
as antecedentsand how AO interpretationsare derived will however requirethe productionand
analysisof anannotatedcorpussuchasthatdescribedin Chapter4, andshould,moreover, consider
theanalysesalreadyproposedfor discoursedeixis.
282
![Page 300: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/300.jpg)
Another openquestionconcernsthe incorporationof abstractobjectsinto CenteringTheory
([WJP81]). As discussedin Chapter2, CenteringTheorymodelsdiscourseprocessingfactorsthat
explaindifferencesin theperceivedcoherenceof discourses.Thecentralideais thateachutterance
presentsacenters, e.g.atopicentity; themostcoherentdiscoursesarethosein which,acrossaseries
of utterances,thecenterremainsconstant,andcanbereferredto by a pronoun.To date,however,
referenceto abstractobjectentitiesin CT hasonly beenconsideredin termsof discoursedeixis
reference(see[Eck98]). The effect of adverbial referenceto abstractobjectentitieson discourse
coherencehasnotbeenconsidered.It wouldbevery interestingto studyif andhow CT can“scale-
up” to thediscourselevel andincorporatenon-reifedclausalinterpretationsandrelationsbetween
themsuppliedby discourseconnectivesandinference.
Anotherline of researchconcernsthe extensionof the corpus-basedinvestigationsperformed
in this thesisto adverbials in other languages.For example, in English we were often able to
illustrate semanticargumentsby making them overt (e.g. in addition to this). According to a
Germanspeaker1, in German,similar semanticargumentsarenot optional;they areeitherexplicit
or lexically incorporatedinto theadverbial. For example,asshown in (6.1) theGermanequivalent
of as a result is infelicitous,but theequivalentof asa resultof that is fine, andeven betteris the
casewherethepreposition,demonstrative,andindefinitenounareincorporatedinto asinglelexical
item.
(6.1)
bad “als Folge” “asa result”
fine “als Folgedessen” “asa resultof that”
better “demzufolge” “dem”=“that”
“zu”=“as”
While we find a discussionin [Ale97] of somecross-linguisticpropertiesof adverbials,includ-
ing similaritiesin scope,positionandmeaning,it would bewell worthwhileto studythesemantic
equivalentsacrosslanguagesof the discourseadverbialsfound in our dataset, to seeif the same
semanticmechanismsareemployed to causethem to function as discourseconnectives. In this
way we would alsofurther enlarge the dataset,enablingthe developmentof a widely applicable
adverbialsemantics.1SIGDial reviewer, personalcommunication
283
![Page 301: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/301.jpg)
Another importantline of researchconcernsthe practicalapplicationof the investigationsin
this thesisandof DLTAG in general.In Chapter3, for example,we discussedonenaturallanguage
generationsystem(SPUD,[SD97]). It wouldbeinterestingto seeif incorporatingdiscoursesyntax
andsemanticsinto suchsystemsimproves their efficiency andresults. The corpusannotationof
discoursesyntaxandsemantics,moreover, shouldleadto anaphoraresolutionalgorithmsfor the
anaphoricargumentsof discourseadverbials,andmay alsohelp improve question-answeringand
otherinformation-retrieval systems,which needto know what to look for, preferablywith a mini-
mumof humaninteraction.For example,if sucha systemrunsacrossasa resultin sometext, then
it shouldknow immediatelyto look for a cause, even if this object is not explicitly statedin the
samesentenceor prior sentences.
Finally, a significanttaskremainingis to investigatehow theDLTAG structuresandinterpreta-
tions built from thesyntaxandsemanticsof discourseconnectivescanbe incorporatedinto high-
level modulesof both discourseand dialogue. While DLTAG simplifies the constructionof an
intermediatelevel of discourse,the relationshipbetweenhow DLTAG discoursetreescombineto
makeentirediscoursesanddialogues,theconstraints,if any, thesestructuresplaceonanaphorares-
olution, andhow inferenceandotheraspectsof discoursecoherence,including focusandGricean
implicatureareto beincorporated,all remainvery interestingsubjectsfor futurestudy.
284
![Page 302: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/302.jpg)
Bibliography
[AC74] D. Allen andA. Cruttenden.Englishsentenceadverbials:Their syntaxandtheir into-
nationin British English.Lingua, 34:1–30,1974.
[Ale97] A. Alexiadou. AdverbPlacement:A CaseStudyin AntisymmetricSyntax. JohnBen-
jaminsPublishingCompany, 1997.
[Ash93] N. Asher. Referenceto Abstract Objects. Kluwer, Dordrecht,1993.
[Aus61] J.Austin. PhilosophicalPapers. 1961.Reprintedin J.L. Austin,PhilosophicalPapers,
ed.by J.O. UrmsonandGeoffrey J.Warnock(Oxford,1990).
[Bea97] D. Beaver. Presupposition.In J. vanBenthemandA. ter Meulen,editors,Handbook
of Logic andLanguage, pages939–1007.Elsevier ScienceB.V., 1997.
[Bie01] G. Bierner. AlternativePhrases:Theoretical AnalysisandPracticalApplication. PhD
dissertation,Universityof Edinburgh,2001.
[Bik00] D. Bikel. A statisticalmodelfor parsingandword-sensedisambiguation,2000.
[Bla87] DianeBlakemore.SemanticConstraintson Relevance. Blackwell,Oxford,1987.
[Bos95] J.Bos. Predicatelogic unplugged.In P. Dekker andM. Stokhof,editors,Proceedings
of the10thAmsterdamColloguium, pages133–142.1995.
[BP83] J. BarwiseandJ. Perry. Situationsand Attitudes. The MIT Press,Cambridge,MA,
1983.
285
![Page 303: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/303.jpg)
[BWFP87] SusanBrennan,Marilyn Walker-Friedman,andCarlPollard.A Centeringapproachto
pronouns.In Proceedingsof the25thAnnualMeetingof theAssociationfor Compu-
tational Linguistics, pages155–162,Stanford,CA, 1987.
[Byr00] D. Byron. Semanticallyenhancedpronouns.Proceedingsof theDiscourseAnaphora
andReferenceResolutionConference(DAARC2000), 12,2000.
[CFM�
02] C. Creswell,K. Forbes,E. Miltsakaki, R. Prasad,B. Webber, andA. Joshi. Thedis-
courseanaphoricpropertiesof connectives. Proceedingsof DAARC, 2002.
[CFM�
03] C. Creswell, K. Forbes, E. Miltsakaki, JasonTeeple, B. Webber, and A. Joshi.
Anaphoricargumentsof discourseconnectives: Semanticpropertiesof antecedents
versusnon-antecedents.Proceedingsof EACL, 2003.
[CFS97] A. Copestake, D. Flickinger, andI. Sag.Minimal RecursionSemantics.An Introduc-
tion. Manuscript,Stanford University, 1997.
[Cho71] N. Chomsky. Deep structure,surface structure,and semanticrepresentation. In
D. Steinberg andL. Jakobovitz, editors,Semantics, pages193–217.CambridgeUni-
versityPress,Cambridge,1971.
[Cho76] N. Chomsky. Conditionson rulesof grammar. Linguistic Analysis, pages303–351,
1976.
[CL93] N. Chomsky andH. Lasnik. The theoryof principlesandparameters.In J. Jacobs,
A. von Stechow, W. Sternefeld,andT. Venneman,editors,Syntax:An International
Handookof Contemporary Research, pages506–569.Mouton de Gruyter, Berlin,
1993.
[Coh84] R. Cohen. A computationaltheoryof the functionof cluewordsin argumentunder-
standing. Proceedingsof the 10th InternationalConferenceon ComputationalLin-
guistics, pages251–258,1984.
286
![Page 304: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/304.jpg)
[CQ52] A. ChurchandW. Quine. Sometheoremson definabilityanddecidability. Journal of
SymbolicLogic, 17:179–187,1952.
[CW00] StephenClark andDavid Weir. A class-basedprobabilisticapproachto structuraldis-
ambiguation,2000.
[Dav67] D. Davidson.Thelogical form of actionsentences.In N. Rescher, editor, TheLogic of
DecisionandAction. Universityof Pittsburgh Press,Pittsburgh, PA, 1967. Reprinted
in D. Davidson,EssaysonActionsandEvents, Oxford: OxfordUniversityPress,1982,
pp.105-122.
[DH95] O. Dahl andC. Hellman. Whathappenswhenwe useananaphor. In Presentationat
theXVthScandinavianConferenceof Linguistics, Oslo,Norway, 1995.
[DiE89] B. DiEugenio. Clausalreferencein Italian. In Proceedingsof thePennsylvaniaLin-
guisticsColloquium, Philadelphia,PA, 1989.
[Dow79] D. Dowty. Word MeaningandMontagueGrammar. D. Reidel,Dordrecht,1979.
[Eck98] M. Eckert. DiscourseDeixisandNull Anaphora in German. PhDdissertation,Uni-
versityof Edinburgh,1998.
[EM90] MichaelElhadadandKathleenMcKeown. Generatingconnectives. In Proceedingsof
COLING. Helsinki,Finland,1990.
[Ern84] ThomasErnst. Toward an Integrated Theoryof AdverbPosition in English. PhD
dissertation,IndianaUniversity, 1984.
[ES99] M. Eckert andM. Strube.Resolvingdiscoursedeicticanaphorain dialogues.In Pro-
ceedingsof the9th Conferenceof theEuropeanChapterof theAssociationfor Com-
putationalLinguistics, Bergen,Norway, 1999.
[Fir64] JanFirbas. On definingthe themein functionalsentenceanalysis.TravauxLinguis-
tiquesdePrague, 1:229–236,1964.
287
![Page 305: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/305.jpg)
[FM02] K. ForbesandE. Miltsakaki. Empiricalstudiesof centeringshiftsandcuephrasesas
embeddedsegmentboundarymarkers. University of PennsylvaniaWorking Papers in
Linguistics, 7(2),2002.
[FMP�
01] K. Forbes,E. Miltsakaki, R. Prasad,A. Sarkar, B. Webber, andA. Joshi. D-LTAG
system:Discourseparsingwith alexicalizedtree-adjoininggrammar. In ESSLLI’2001
Workshopon Information Structure, Discourse Structure and Discourse Semantics.
Helsinki,Finland,2001.
[Fox87] BarbaraFox. DiscourseStructure andAnaphora: writtenandconversationalEnglish.
CambrideUniversityPress,Cambridge,England,1987.
[Fra88] Bruce Fraser. Types of English discoursemarkers. Acta Linguistica Hungaria,
38(1):19–33,1988.
[FvG01] Anette Frank and Josefvan Genabith. Gluetag: Linear logic basedsemanticsfor
LTAG-andwhat it teachesusaboutLFG andLTAG. In Miriam Butt andTracy Hol-
loway King, editors,Proceedingsof theLFG01Conference. CSLI Publications,2001.
[FW02] K. ForbesandB. Webber. A semanticaccountof adverbialsasdiscourseconnectives.
Philadelphia,PA, 2002.
[Gar97a] C. Gardent. Interpretingfocus. PresentationSlides for ESSLI 1997 Conference,
http://www.coli.uni-sb.de/. claire/teaching/essll97/essli97-lect3.ps,1997.
[Gar97b] ClaireGardent.DiscourseTAG. Clausreportnr.89,Universityof theSaarland,Saar-
brucken,1997.
[Gaw86] J. Gawron. Situationsandprepositions.Linguisticsand Philosophy, 9(3):327–382,
1986.
[Gaz79a] G. Gazdar. Pragmatics: Implicature, Presuppositionand Logical Form. Academic
Press,New York, 1979.
288
![Page 306: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/306.jpg)
[Gaz79b] G. Gazdar. A solutionto theprojectionproblem. In Oh andDineen,editors,Syntax
andSemantics11: Presupposition, pages57–89.AcademicPress,New York, 1979.
[Gaz99] GeraldGazdar. http://www.cogs.susx.ac.uk/lab/nlp/gazdar/teach/nlp/nlp.html, 1999.
[GC00] S. Gustafson-Capova. The influenceof prosodicprominenceon the interpretationof
ambiguousanaphorsin Swedish.Proceedingsof theDiscourseAnaphora andRefer-
enceResolutionConference(DAARC2000), 12,2000.
[GHZ93] J. Gundel,N. Hedberg, andR. Zacharski.Cognitive statusandthe form of referring
expressionsin discourse.Language, 69,1993.
[gra] http://www.edufind.com/english/grammar/DETERMINERS1.cfm.
[Gre69] S.Greenbaum.Studiesin EnglishAdverbialsUsage. Longmans,London,1969.
[Gri75] H. P. Grice. Logic andconversation. In P. Cole andJ. Morgan,editors,Syntaxand
Semantics,vol. 3, pages41–58.AcademicPress,1975.
[Gri89] H. P. Grice. Studies in the Way of Words. Harvard University Press,
Cambridge, MA, 1989. A summary of Grice’s work can be found at:
http://www.artsci.wustl.edu/. philos/MindDict/grice.html.
[Gro99] The XTAG ResearchGroup. A Lexicalized Tree Adjoining Grammarfor English.
http://www.cis.upenn.edu/. xtag,1999.
[GS86] B. GroszandC. Sidner. Attention,intentionandthestructureof discourse.Journalof
ComputationalLinguistics, 12:175–204,1986.
[Hal67] M. Halliday. Noteson transitivity andthemein English. Journal of Linguistics, 3,
1967.
[Har99] D. Hardt. Dynamicinterpretationof verbphraseellipsis. LinguisticsandPhilisophy,
22:187–221,1999.
289
![Page 307: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/307.jpg)
[Hei82] IreneHeimt. Semanticsof Definiteand IndefiniteNounPhrases. PhD dissertation,
Universityof Massachusetts,1982.
[HH76] M. HallidayandR. Hasan.Cohesionin English. Longman,London,1976.
[Hir91] JuliaHirschberg. A Theoryof ScalarImplicature. GarlandPublishingCompany, New
York,1991.Publishedversionof Ph.D.Dissertation,Universityof Pennsylvania,1985.
[HK98] IreneHeimandAngelaKratzer. Semanticsin GenerativeGrammar. Blackwell,1998.
[Hob85] JerryHobbs.Ontologicalpromiscuity. In Proceedingsof the23<�� AnnualMeetingof
theAssociationfor ComputationalLinguistics, pages61–69.PaloAlto, CA, 1985.
[Hob90] JerryHobbs.Literatureandcognition.CSLILecture Notes, 21,1990.
[Hor69] L. Horn. A presuppositionaltheoryof ‘only’ and‘even’. CLS5, Chicago Linguistics
Society, 1969.
[Hor96] L. Horn. Presuppositionand implicature. In S. Lappin, editor, The Handbookof
Contemporary SemanticTheory, pages299–319.Blackwell,Oxford,1996.
[Hov90] EduardHovy. Parsimoniousandprolifigateapproachesto the questionof discourse
structurerelations. In Proceedingsof the Fifth International Workshopon Natural
Language Generation, pages128–136.1990.
[Hov93] EduardHovy. Automateddiscoursegenerationusing discoursestructurerelations.
Artificial Intelligence, 63:69–142,1993.
[Hov95] EduardHovy. The multifunctionality of discoursemarkers. In Proceedingsof the
Workshopon DiscourseMarkers. Holland,January, 1995.
[HSAM93] JerryHobbs,Mark Stickel, DouglasAppelt,andPaulMartin. Interpretationasabduc-
tion. Artificial Intelligence, pages69–142,1993.
[Hum48] David Hume.An Inquiry ConcerningHumanUnderstanding. TheLiberal Arts Press,
New York, 1955edition,1748.
290
![Page 308: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/308.jpg)
[Jac72] R. Jackendoff. SemanticInterpretation in Generative Grammar. MIT Press,Cam-
bridge,MA, 1972.
[Jac90] R. Jackendoff. Semanticstructures. In Current Studiesin LinguisticsSeries. Cam-
bridge,MA, 1990.
[JKR03] Aravind Joshi,LauraKallmeyer, andMaribelRomero.Flexible compositionin LTAG:
Quantifierscopeandinverselinking. In Proceedingsof theInternationalWorkshopon
CompositionalSemantics. Tilburg, TheNetherlands,2003.
[Joh95] MichaelJohnston.dxV;.�W -clauses,adverbsof quantification,andfocus.In Proceedings
of WCCFL13,Stanford LinguisticsAssociation, CLSI, StanfordUniversity, 1995.
[Jos87] Aravind Joshi.An introducationto treeadjoininggrammar. In Alexis Manaster-Ramer,
editor, Mathematicsof Language, pages87–114.JohnBenjamins,Amsterdam,1987.
[JR98] J. Jayezand R. Rossari. Discourserelationsversusdiscoursemarker relations. In
Proceedingsof the ACL Workshopon Discourse Relationsand Discourse Markers,
pages72–78.Montreal,Canada,1998.
[JVS99] A. Joshi and K. Vijay-Shanker. Compositionalsemanticswith lexicalized tree-
adjoininggrammar(LTAG): How muchunderspecificationis necessary?In Alexis
Manaster-Ramer, editor, Proceedingsof theThird InternationalWorkshopon Compu-
tational Semantics. Tilburg, Netherlands,January, 1999.
[Kal02] LauraKallmeyer. UsinganenrichedTAG derivationstructureasbasisfor semantics.
In Proceedingsof theSixthInternationalWorkshopon TreeAdjoiningGrammarand
RelatedFrameworks(TAG+6), pages101–110.Universityof Venice,2002.
[Kam79] H. Kamp. Events, instants,and temporalreference. In R. Baeuerleet al., editor,
SemanticsfromDifferentPointsof View. SpringerVerlag,Berlin, 1979.
[Kar73] L. Karttunen.Presuppositionsof compoundsentences.Linguistic Inquiry, 4(2):169–
193,1973.
291
![Page 309: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/309.jpg)
[Kas93] R.Kasper. Adjunctsin themittelfeld. In J.Nerbonne,K. Netter, andC.Pollard,editors,
Germanin Head-DrivenPhraseStructure Grammar, Lecture NoteSeries,Chapter4,
pages39–69.Utrecht,TheNetherlands,1993.
[Keh95] Andrew Kehler. Interpreting CohesiveFormsin the Context of DiscourseInference.
PhDdissertation,HarvardUniversity, 1995.
[KJ99] LauraKallmeyer andAravind Joshi. Factoringpredicateargumentandscopeseman-
tics: Underspecifiedsemanticswith LTAG. In Paul Dekker, editor, Proceedingsof the
12thAmsterdamColloquium, pages169–174.Amsterdam,December, 1999.To appear
in theJournalof LanguageandComputation,2002.
[KK70] P. Kiparsky andC.Kiparsky. Fact. In M. BierwischandK. Heidolph,editors,Progress
in Linguistics, pages143–13.Mouton,TheHague,1970. Also in (PetofiandFranck,
1973).
[KKR91] R. Kittredge,T. Korelsky, andO. Rambow. On theneedfor domaincommunication
knowledge.ComputationalIntelligence, 7:305–314,1991.
[KKW01a] I. Kruijf f-Korbayova andB. Webber. Concession,implicature,and alternative sets.
In Proceedingsof theInternationalWorkshoponComputationalSemantics(IWCS-4),
Tilburg, January, 2001.
[KKW01b] I. Kruijf f-Korbayova andB. Webber. Informationstructureandthe interpretationof
‘otherwise’. In ESSLLI2001Worshopon InformationStructure, DiscourseStructure,
andDiscourseSemantics, pages61–78,Helsinki,Finland,2001.
[Kno96] Ali Knott. A Data-DrivenMethodology For MotivatingA Setof CoherenceRelations.
PhDdissertation,Universityof Edinburgh,1996.
[Kon91] EkkehardKonig. TheMeaningof FocusParticles: A ComparativePerspective. Rout-
ledge,London,1991.
292
![Page 310: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/310.jpg)
[KOOM01] A. Knott, J. Oberlander, M. O’Donnell, andC. Mellish. Beyond Elaboration: The
interactionof relationsandfocusin coherenttext. In J. SchilperoordT. Sandersand
W. Spooren,editors,Text representation:linguisticandpsycholinguisticaspects, pages
181–196.Benjamins,2001.
[KP79] L. Karttunenand S. Peters. Conventional implicature. In C. Oh and D. Dinneen,
editors,Syntaxand Semantics:Presupposition,volume11, pages1–56.Academic
Press,New York, 1979.
[KP02] Paul Kingsbury andMarthaPalmer. FromTreebankto Propbank.In Proceedingsof
theThird InternationalConferenceonLanguageResourcesandEvaluation,LREC-02.
LasPalmas,CanaryIslands,Spain,May 28-June3, 2002.
[KR93] H. KampandU. Reyle. FromDiscourseto Logic. Kluwer AcademicPublishers,1993.
[Kra89] A. Kratzer. An investigationof thelumpsof thought.LinguisticsandPhilosophy, 12,
1989.
[Kri] M. Krif a. Focus.http://cognet.mit.edu/MITECS/Entry/krifka2.
[Kri92] M. Krifka. A compositionalsemanticsfor multiple focusconstructions.CornellWork-
ing Papers in Linguistics, 10:127–158,1992.
[LA90] D. Litman andJ. Allen. Discourseprocessingandcommonsenseplans. In P. Cohen,
J.Morgan,andM. Pollack,editors,Intentionsin Communication. MIT Press,1990.
[LA93] A. LascaridesandN. Asher. Temporalinterpretation,discourserelationsandcommon-
senseentailment.LinguisticsandPhilosophy, 16:437–493,1993.
[LA99] A. LascaridesandN. Asher. Cognitive states,discoursestructure,andthecontentof
dialogue.In Proceedingsto Amstelogue. 1999.
[Lad66] R.Ladd.IntonationalPhonology. CambridgeUniversityPress,Cambridge,MA, 1966.
[Lag98] Luuk Lagerwerf. Causal ConnectivesHave Presuppositions. Holland Academic
Graphics,TheHague,1998.
293
![Page 311: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/311.jpg)
[Lak74] R. Lakoff. Remarksonthisandthat. In Papers fromtheTenthRegionalMeetingof the
Chicago LinguisticSociety. 1974.
[Lit98] K. Litkowski. Analysisof subordinatingconjunctions.CL ResearchTechnicalReport
(Draft) 98-01,CL Research,Gaithersburg, MD, 1998. http://www.clres.com/online-
papers/sc.html.
[LO93] A. Lascaridesand J. Oberlander. Temporalconnectives in a discoursecontext. In
Proceedingsof the 6th InternationalConferenceof the EuropeanChapterof the As-
sociationfor ComputationalLinguistics, pages260–268.Utrecht, The Netherlands,
1993.
[Lon83] RobertLongacre.TheGrammarof Discourse. PlenumPress,New York, 1983.
[Lyo77] J.Lyons.Semantics. CambridgeUniversityPress,Cambridge,MA, 1977.
[Mar92] J.R.Martin. EnglishText: SystemandStructure. Benjamin,Amsterdam,1992.
[Mar97] Daniel Marcu. Instructionsfor manuallyannotatingthe discoursestructureof texts.
http://www.isi.edu/. marcu/software.html, 1997.
[Mar99] DanielMarcu.A formalandcomputationalsynthesisof GroszandSidner’sandMann
and Thompson’s theories. In Workshopon Levels of Representationin Discourse.
Edinburgh,Scotland,1999.
[Mar00] DanielMarcu. Therhetoricalparsingof unrestrictedtexts: A surface-basedapproach.
ComputationalLinguistics, 25(3):395–448,2000.
[McC88] J.D. McCawley. TheSyntacticPhenomenaof English. The University of Chicago
Press,1988.
[McL01] Mark McLauchlan. Maximum entropy modelsandprepositionalphraseambiguity,
2001.
[MG82] Sally McConell-Ginet.Adverbsandlogical form. Language, 58:144–184,1982.
294
![Page 312: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/312.jpg)
[Mit82] Anita Mittwoch. On the differencebetweeneatingandeatingsomething:Activities
versusaccomplishments.LinguisticInquiry, 13,1982.
[Mod01] N. Modjeska. Towardsa resolutionof comparative anaphora:A corpusstudy of
‘other’. In PAPACOL. Italy, 2001.
[Mon74] R. Montague.On thenatureof certainphilosophicalentities.In R. Thomason,editor,
Formal Philosophy, pages148–187.YaleUniversityPress,New Haven,CT, 1974.
[Moo93] R. Moore. Events,situationsandadverbs. In R. WeischedelandM. Bates,editors,
Challengesin Natural LanguageProcessing. CambridgeUniversityPress,Cambridge,
1993.
[MP92] JohannaMoore andMarthaPollack. A problemfor RST: The needfor multi-level
discourseanalysis.ComputationalLinguistics, 18(4):537–544,1992.
[MP93] JohannaMooreandCecileParis. Planningtext for advisorydialogues:Capturingin-
tentionalandrhetoricalinformation.ComputationalLinguistics, 19(4):651–694,1993.
[MS88] MarcMoensandMark Steedman.Temporalontologyandtemporalreference.Journal
of ComputationalLinguistics, 14(2):15–28,1988.
[MT88] William Mann andSandraThompson.RhetoricalStructureTheory: Towarda func-
tional theoryof text organization.Text, 8(3):243–281,1988.
[MTC95] Gail Mauner, Michael Tanenhaus,andGreg Carlson. Implicit argumentsin sentence
processing.Journalof MemoryandLanguage, 34:357–382,1995.
[MW] OnlineMiriam-WebsterDictionary, http://www.m-w.com/home.htm.
[Nun79] G. Nunberg. The non-uniquenessof semanticsolutions:Polysemy. Linguisticsand
Philosophy, 3, 1979.
[ODA93] W. O’Grady, M. Dobrovolsky, and M. Aronoff. Linguistics: An Introduction. St.
Martin’s Press,New York, 1993.
295
![Page 313: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/313.jpg)
[Par84] BarbaraPartee.Nominalandtemporalanaphora.LinguisticsandPhilosophy, 7:243–
286,1984.
[Pas91] R. Passonneau.Somefactsaboutcenters,indexicals,anddemonstratives.Proceedings
of the29thAnnualMeetingof theACL, 1991.
[Per90] FernandoPereira. Categorial semanticsand scoping. ComputationalLinguistics,
16(1):1–10,1990.
[PH90] J. PierrehumbertandJ. Hirschberg. Themeaningof intonationcontoursin the inter-
pretationof discourse.In P. Cohen,J. Morgan,andM. Pollack,editors,Intentionsin
Communication, pages271–312.MIT Press,Cambridge,MA, 1990.
[Pol96] Livia Polanyi. TheLinguisticStructureof Discourse. CSLI TechnicalReport,Stanford
CA, 1996.
[Pri81] E. Prince. Towarda taxonomyof given/new information. In P. Cole,editor, Radical
pragmatics. AcademicPress,NY, 1981.
[Pri86] E. Prince. On thesyntacticmarkingof presupposedopenpropositions.In A. Farley,
P. Farley, andK. McCullough, editors,Papers from the Parasessionon Pragmatics
andGrammaticalTheory, 22ndRegionalMeeting, pages208–222.ChicagoLinguistic
Society, 1986.
[PS87] C. PollardandI. Sag. Informationbasedsyntaxandsemantics.In Volume1: Funda-
mentals. Stanford,CA: Centerfor theStudyof LanguageandInformation,1987.
[PSvdB94] H. Prust,R.Scha,andM. vandenBerg. Discoursegrammarandverbphraseanaphora.
LinguisticsandPhilosophy, 17:261–327,1994.
[PT] PennTreebank.Seehttp://www.ldc.upenn.edu/ldc/online/treebank/ for documentation.
[Pul97] S. Pulman. Higher orderunificationandthe interpretationof focus. Linguisticsand
Philosophy, 20:73–115,1997.
296
![Page 314: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/314.jpg)
[PvdB96] Livia Polanyi andMartin van denBerg. Discoursestructureanddiscourseinterpre-
tation. In P. Dekker andM. Stokhof, editors,Proceedingsof the TenthAmsterdam
Colloquium. ILLC, Amsterdam,1996.
[PvdB99] Livia Polanyi and Martin van den Berg. Logical structureand discourseanaphora
resolution.In D. Cristea,N. Ide,andD. Marcu,editors,Proceedingsof theWorkshop
on therelationof Discourse/DialogueStructure andReference. 37thAnnualMeeting
of theAssociationof ComputationalLinguistics,1999.
[QGLS85] R. Quirk, S.Greenbaum,G. Leech,andJ.Svartvik. A ComprehensiveGrammarof the
EnglishLanguage. Longman,London,1985.
[Qui72] R. Quirk. A Grammarof Contemporary English. Longman,London,1972.
[Red90] GiselaRedeker. Ideationalandpragmaticmarkersof discoursestructure.Journal of
Pragmatics, 14:367–381,1990.
[Roo85] M. Rooth. Associationwith Focus. PhD dissertation,University of Massachusetts,
Amherst,1985.
[Roo92] M. Rooth. A theoryof focusinterpretation.Natural Language Semantics, 1:75–116,
1992.
[Roo95a] M. Rooth. Focus.In S.Lappin,editor, Handbookof Contemporary SemanticTheory,
pages271–298.Blackwell,London,1995.
[Roo95b] M. Rooth. Indefinites,adverbsof quantification,andfocussemantics.In G. Carlson,
editor, Generics. 1995.
[Sac77] E. Sacerdoti.A Structure for PlansandBehavior. Elsevier, Amsterdam,1977.
[Sae96] K. Saeboe.Anaphoricpresuppositionsandzeroanaphora.LinguisticsandPhilosophy,
19:187–209,1996.
297
![Page 315: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/315.jpg)
[SBDP00] Matthew Stone,ToniaBleam,ChristineDoran,andMarthaPalmer. Lexicalizedgram-
mar andthe descriptionof motion events. In WorkshopTAG/ 5, Paris, 25-27May,
2000.
[Sch71] P. Schreiber. Someconstraintsontheformationof Englishsentenceadverbs.Linguistic
Inquiry, 2(1),1971.
[Sch85] R. Schiffman. DiscourseConstraints on ‘it’ and ‘that’: A studyof language usein
career-counselinginterviews. PhDdissertation,Universityof Chicago,1985.
[Sch87] D. Schiffrin. DiscourseMarkers. CambridgeUniversityPress,Cambridge,MA, 1987.
[Sch97] FrankSchilder. Treediscoursegrammar, or how to get attachedto a discourse. In
P. Dekker andM. Stokhof,editors,Proceedingsof theSecondInternationalWorkshop
on ComputationalSemantics. Tilburg, Netherlands,1997.
[SCT�
94] J. Sedivy, G. Carlson,M. Tanenhaus,M. Spivey-Knowlton, andK. Eberhard. The
cognitive functionof contrastsetsin processingfocusconstructions.In P. Boschand
R. vanderSandt,editors,FocusandNatural Language Processing. IBM Deutschland
InformationssystemeGmbH,Institutefor Logic andLinguistics,1994.
[SD97] Matthew Stoneand ChristineDoran. Sentenceplanningas descriptionusing tree-
adjoininggrammar. Proceedingsof the 35th AnnualMeetingof the Associationfor
ComputationalLinguistics(ACL), pages198–205,1997.
[SdS90] D. R. ScottandC. S. de Souza. Gettingthe messageacrossin RST-basedtext gen-
eration. In R. Dale, C. Mellish, andM. Zock, editors,Current Research in Natural
Language Generation. AcademicPress,1990.
[Sea69] J.Searle.Speech Acts:AnEssayin thePhilosophyof Language. CambridgeUniversity
Press,Cambridge,MA, 1969.
[Shi86] StuartShieber. An Introductionto Unifcation-BasedApproachesto Grammar. CSLI,
Stanford,CA, 1986.
298
![Page 316: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/316.jpg)
[SHP73] P. Sgall,E. Hajicova,andE. Penesova. Topic,FocusandGenerativeSemantics. Scrip-
tor, Kronberg andTaunus,1973.
[Sib92] P. Sibun. Generatingtext without trees. ComputationalIntelligence, 8(1):102–122,
1992.
[SIG02] Proceedingsof the Third SIGdial Workshopon DiscourseandDialogue,11-12July,
Philadelphia,PA, 2002.
[Sil76] Michael Silverstein. Shifters, linguistic categories and cultural descriptions. In
K. BassoandH. Selby, editors,Meaningin Anthropology, pages11–55.University
of New Mexico Press,1976.
[Sim00] MandySimons.Why somepresuppositionsareconversationalimplicatures.Handout
for University of Pennsylvania LinguisticsSpeaker SeriesTalk, November9, 2000.
Dept.of Philosophy, Carnegie Mellon University.
[SP88] R. SchaandL. Polanyi. An augmentedcontext freegrammarfor disocurse.In Pro-
ceedingsof the 12th International Conferenceon ComputationalLinguistics, pages
22–27.COLING, 1988.
[SSN93] TedSanders,Wilbert Spooren,andLeoNoordman.Coherencerelationsin acognitive
theoryof discourserepresentation.CognitiveLinguistics, 4(2):93–133,1993.
[Sta74] R.Stalnaker. Pragmaticpresuppositions.In M. MunitzandP. Unger, editors,Semantics
andPhilosophy, pages197–214.New York UniversityPress,1974.
[Ste96] M. Steedman.SurfaceStructure andInterpretation. TheMIT Press,Cambridge,MA,
1996.
[Ste00a] M. Steedman.Informationstructureandthe syntax-phonologyinterface. Linguistic
Inquiry, 31(4):649–689,2000.
[Ste00b] M. Steedman.Theproductionsof time: temporalityandcausalityin linguistic seman-
tics. Draft, 2000.
299
![Page 317: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/317.jpg)
[Ste00c] M. Steedman.TheSyntacticProcess. TheMIT Press,Cambridge,MA, 2000.
[Sto94] M. Stone. Discoursedeixis,discoursestructure,andthesemanticsof subordination.
Ms.,1994.
[Str59] P. Strawson.On referring.Mind, 235:320–344,1959.
[Suz97] H. Suzuki.Noteson thegrammarof -ly adverbsin English.Typological Investigation
of LanguagesandCulturesof theEastandWest, 1997.
[SW86] D. SperberandD. Wilson. Relevance. Harvard University Press,Cambridge,MA,
1986.
[Swa88] T. Swan. SentenceAdverbialsin English: A Synchronic andDiachronic Investigation.
Novus,Tromso-Studieri SprakvitenskapX, Oslo,1988.
[Umb02] CarlaUmbach.Contrastandcontrastive topic. In IvanaKruijf f-Korbayova andMark
Steedman,editors,ESSLLI2001WorkshoponInformationStructure, DiscourseStruc-
ture andDiscourseSemantics, 2002.
[vD79] T. vanDijk. Pragmaticconnectives. Journal of Pragmatics, 3:447–456,1979.
[vdB96] Martin van den Berg. Discoursegrammarand dynamic logic. In P. Dekker and
M. Stokhof,editors,Proceedingsof the TenthAmsterdamColloquium. ILLC, Ams-
terdam,1996.
[vdG69] G. von derGabelentz.IdeenzueinervergleichendenSyntax. Wort undSatzstellung,
Zeitschriftfur VolkerpsychologieundSprachwissenschaft6, 1869.
[vdS92] R. vanderSandt.Presuppositionprojectionasanaphoraresolution.Journalof Seman-
tics, 9:333–377,1992.
[Ven67] Z. Vendler. Linguisticsin Philosophy. CornellUniversityPress,Cornell,NY, 1967.
[Ver97] CorneliaMaria Verspoor. Contextually-Dependent Lexical Semantics. PhD disserta-
tion, Universityof Edinburgh,1997.
300
![Page 318: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/318.jpg)
[vH00] K. vonHeusinger. Accessibility, discourseanaphora,anddescriptivecontent.Proceed-
ingsof theDiscourseAnaphora andReferenceResolutionConference(DAARC2000),
12,2000.
[vS82] A. vonStechow. Structuredpropositions.Arbeitspapier59desSonderforschungsbere-
ichs99.UniversitatKonstanz,1982.
[Wal93] Marilyn Walker. InformationalRedundancyandResourceBoundsin Dialogue. PhD
dissertation,Universityof Pennsylvania,1993.
[web] http://cctc.commnet.edu/grammar/adverbs.htm,
http://www.cis.upenn.edu/. xtag/tech-report/node173.html,
http://faculty.washington.edu/ . marynell/grammar/AdverbPl.html.
[Web88] B. Webber. Discoursedeixis: Referenceto discoursesegments. Proceedingsof the
26thAnnualMeetingof theAssociationfor ComputationalLinguistics, 1988.
[Web91] B. Webber. Structureandostensionin theinterpretationof discoursedeixis.Language
andCognitiveProcesses, 6(2),1991.
[WJ98] B. WebberandA. Joshi.Anchoringa lexicalizedtree-adjoinggrammarfor discourse.
In Proceedingsof the Coling/ACL Workshopon Discourse Relationsand Discourse
Markers, pages86–92.Montreal,Canada,1998.
[WJP81] M. Walker, A. Joshi,andE. Prince. Centeringin naturallyoccurringdiscourse:An
overview. In M. Walker, A. Joshi,andE. Prince,editors,CenteringTheoryin Dis-
course. ClarendonPress,Oxford,1981.
[WJSK99] B. Webber, A. Joshi,M. Stone,andA. Knott. Discourserelations:A structuraland
presuppositionalaccountusing lexicalisedTAG. In Proceedingsof the 36th Annual
Meetingof theAssociationfor ComputationalLinguistics, pages41–48.CollegePark,
MD, 1999.
301
![Page 319: Thesis about discourse](https://reader033.fdocuments.net/reader033/viewer/2022052217/554997dfb4c9050c708b473c/html5/thumbnails/319.jpg)
[WJSK03] Bonnie Webber, Aravind Joshi,Matthew Stone,and Alistair Knott. Anaphoraand
discoursesemantics.To appearin ComputationalLinguistics, 2003.
[WKJ99] B. Webber, A. Knott, andA. Joshi. Multiple discourseconnectives in a lexicalised
grammarfor discourse.In Proceedingsof the3rd InternationalWorkshopon Compu-
tational Semantics, pages309–325.Tilburg, TheNetherlands,1999.
[WN98] FivePapersonWordNet,1998.ftp://ftp.cogsci.princeton.edu/pub/wordnet/5papers.ps.
302