Pal gov.tutorial4.session6 1.ontologyengineeringchallenges

1PalGov © 2011 1PalGov © 2011

أكاديمية الحكومة اإللكترونية الفلسطينيةThe Palestinian eGovernment Academy

www.egovacademy.ps

Tutorial 4: Ontology Engineering & Lexical Semantics

Session 6.1

Ontology Engineering Challenges

Dr. Mustafa Jarrar

University of Birzeit

[email protected]

www.jarrar.info

mailto:[email protected]

http://www.jarrar.info/


About

This tutorial is part of the PalGov project, funded by the TEMPUS IV program of the

Commission of the European Communities, grant agreement 511159-TEMPUS-1-

2010-1-PS-TEMPUS-JPHES. The project website: www.egovacademy.ps

University of Trento, Italy

University of Namur, Belgium

Vrije Universiteit Brussel, Belgium

TrueTrust, UK

Birzeit University, Palestine

(Coordinator )

Palestine Polytechnic University, Palestine

Palestine Technical University, PalestineUniversité de Savoie, France

Ministry of Local Government, Palestine

Ministry of Telecom and IT, Palestine

Ministry of Interior, Palestine

Project Consortium:

Coordinator:

Dr. Mustafa Jarrar

Birzeit University, P.O.Box 14- Birzeit, Palestine

Telfax:+972 2 2982935 [email protected]

http://www.egovacademy.ps/


© Copyright Notes

Everyone is encouraged to use this material, or part of it, but should

properly cite the project (logo and website), and the author of that part.

No part of this tutorial may be reproduced or modified in any form or by

any means, without prior written permission from the project, who have

the full copyrights on the material.

Attribution-NonCommercial-ShareAlike

CC-BY-NC-SA

This license lets others remix, tweak, and build upon your work non-

commercially, as long as they credit you and license their new creations

under the identical terms.

4PalGov © 2011

Tutorial Map

Topic Time

Session 1_1: The Need for Sharing Semantics 1.5

Session 1_2: What is an ontology 1.5

Session 2: Lab- Build a Population Ontology 3

Session 3: Lab- Build a BankCustomer Ontology 3

Session 4: Lab- Build a BankCustomer Ontology 3

Session 5: Lab- Ontology Tools 3

Session 6_1: Ontology Engineering Challenges 1.5

Session 6_2: Ontology Double Articulation 1.5

Session 7: Lab - Build a Legal-Person Ontology 3

Session 8_1: Ontology Modeling Challenges 1.5

Session 8_2: Stepwise Methodologies 1.5

Session 9: Lab - Build a Legal-Person Ontology 3

Session 10: Zinnar – The Palestinian eGovernmentInteroperability Framework

3

Session 11: Lab- Using Zinnar in web services 3

Session 12_1: Lexical Semantics and Multilingually 1.5

Session 12_2: WordNets 1.5

Session 13: ArabicOntology 3

Session 14: Lab-Using Linguistic Ontologies 3

Session 15: Lab-Using Linguistic Ontologies 3

Intended Learning ObjectivesA: Knowledge and Understanding

4a1: Demonstrate knowledge of what is an ontology,

how it is built, and what it is used for.

4a2: Demonstrate knowledge of ontology engineering

and evaluation.

4a3: Describe the difference between an ontology and a

schema, and an ontology and a dictionary.

4a4: Explain the concept of language ontologies, lexical

semantics and multilingualism.

B: Intellectual Skills

4b1: Develop quality ontologies.

4b2: Tackle ontology engineering challenges.

4b3: Develop multilingual ontologies.

4b4: Formulate quality glosses.

C: Professional and Practical Skills

4c1: Use ontology tools.

4c2: (Re)use existing Language ontologies.

D: General and Transferable Skills

d1: Working with team.

d2: Presenting and defending ideas.

d3: Use of creativity and innovation in problem solving.

d4: Develop communication skills and logical reasoning

abilities.


Outline and Session ILOs

This session will help students to:

4a2: Demonstrate knowledge of ontology engineering and evaluation.

4b2: Tackle ontology engineering challenges.


Ontology Engineering Challenges

Ontology Usability versus Ontology Reusability

Ontology Application Dependence

• Only these challenges will be discussed, but there are many other

challenges that may face an ontology engineer.

• Discussing such challenges will help improve the modeling skills of

an ontology engineer.


Ontology Reusability vs UsabilityGiven 4 different LegalPerson ontologies (which is more usable/reusable?)

App1: Ministries’ Web Service to exchange companies’ profiles is based on this ontology.

App2: Champers of commerce’s Web Service to exchange companies’ profiles, based on this ontology.

App3: Banks designed their “new account” form, based on the company properties in this ontology (off time use).

App4: Lawyers refer to the definition of “company”, as stated in this ontology (off time use).

Used by App1, 10 times/day.









Used by App1, 9000 times/day.O1

O2

O3

O4


Ontology Reusability vs Usability

App1: Ministries Web Service to exchange companies profiles is based on this ontology.

App2: Champers of commerce’s Web Service to exchange companies profiles, based on this ontology.













O2

O3

O4

Usability: maximizing the number of different applications using

an ontology for the same kind of task.

Reusability: maximizing the number of different applications using

an ontology over different kind of tasks.

Why Reusability:

1) Saving time, cost, and efforts…

2) Increasing reliability: the more reused the more tested.

3) An important quality factor: a highly reusable ontology is an

indication that it is a good ontology.

How to increase Usability?

by being closer to the application specifications and

requirements at hand.

How to increase Reusability?

by taking into account different usages/applications, i.e. be more

general.

Given 4 different LegalPerson ontologies (which is more usable/reusable?)


Ontology Reusability vs Usability

App1: Ministries Web Service to exchange companies profiles is based on this ontology.

App2: Champers of commerce’s Web Service to exchange companies profiles, based on this ontology.













O2

O3

O4

Usability: maximizing the number of different applications using

an ontology for the same kind of task.

Reusability: maximizing the number of different applications using

an ontology over different kind of tasks.

Why Reusability:

1) Savings in time, cost, and efforts…

2) Increasing reliability: the more reused the more tested.

3) An important quality factor: a highly resalable ontology is an

indication that it is a good ontology.

How to increase Usability?

by being closes to the application specifics and requirements at

hand.

How to increase Reusability?

by taking into account different usages/applications, i.e. be more

general.

Tradeoff between usability and reusability

Usability Reusability

The more an ontology is usable the less reusable it will be,

and vice versa.

A good ontology engineer knows how/where to compromise

this tradeoff.

Given 4 different LegalPerson ontologies (which is more usable/reusable?)

10PalGov © 2011 10PalGov © 2011


The problem is that when building an ontology, there will always be

intended or expected usability requirements -“at hand”- which influence

the independency level of ontology axioms.

Bylander and Chandrasekaran in [BC88]

“Representing knowledge for the purpose of solving someproblem is strongly affected by the nature of the problem andthe inference strategy to be applied to the problem.”

Ontologies are supposed to capture knowledge at the domain level

independently of application requirements [G97] [GB99] [CJB99].

This problem is as the Interaction Problem:

11PalGov © 2011 11PalGov © 2011


Usability perspectives lead to different (and sometimes conflicting)

axiomatizations although these axiomatizations might agree at the domain level.

Bo

oksto

res

Ap

plic

atio

ns

Lib

rary

Ap

plic

atio

ns

?

What is the meaning of a “book” here?

12PalGov © 2011 12PalGov © 2011


Usability perspectives lead to different (and sometimes conflicting)

axiomatizations although these axiomatizations might agree at the domain level.

Bo

oksto

res

Ap

plic

atio

ns

Lib

rary

Ap

plic

atio

ns

?

What is the meaning of a “book” here?

Both are not ontologies, they are data schemes.

Can you build a useful and an application-independent ontology?

PalGov © 2011 13

References

Mustafa Jarrar: Towards methodological principles for ontology engineering. PhD

Thesis. Vrije Universiteit Brussel. (May 2005)

Thomas R. Gruber: Toward Principles for the Design of Ontologies Used for Knowledge

Sharing http://tomgruber.org/writing/onto-design.pdf

Nicola Guarino: Formal Ontology and Information Systems http://www.loa-

cnr.it/Papers/FOIS98.pdf

Guarino, N.: Understanding, building, and using ontologies: A commentary to “Using

Explicit Ontologies in KBS Development”, by van Heijst, Schreiber, and Wielinga."

International Journal of Human and Computer Studies No. 46. (1997) pp. 293–310

[HV93] Hemmann, T., Voss, H.: A Reusable and Specializable Interpretation Model for

ModelBased Diagnosis. In: Luckenhoff, C., Fensel, D., Studer, D. (eds.): Proceeding

3rd KADS Meeting Siemens AG. Munich. March (1993) pp. 189–205

http://www.jarrar.info/phd-thesis/

http://www.jarrar.info/phd-thesis/

http://tomgruber.org/writing/onto-design.pdf



http://www.loa-cnr.it/Papers/FOIS98.pdf





Pal gov.tutorial4.session6 1.ontologyengineeringchallenges

Education

Transcript of Pal gov.tutorial4.session6 1.ontologyengineeringchallenges