Dublin Core Metadata

Besser--Dublin Core Metadata 2/14/02 1

Dublin Core Metadata

Howard Besser

UCLA School of Education & Information

http://www.gseis.ucla.edu/~howard


Metadata for Digital Libraries- Models for Digital Libraries Importance of Metadata Standards Types and Uses of Metadata Discovery Metadata: The Dublin Core


Key problems we’re facing

Discovery Longevity- Interoperability-


Traditional Digital Library Model

DL

DL

DL

DL

useruser

search & presentation





Ideal Digital Library Model

DL

DL

DL

DL

useruser



For Interoperability Digital Libraries Need Standards

Descriptive Metadata for consistent description

Discovery Metadata for finding Administrative Metadata for viewing and

maintaining Structural Metadata for navigation ... Terms & Conditions Metadata for

controlling access...


Why are Standards and Metadata consensus

important? Managing digital files over time Longevity Interoperability Veracity Recording in a consistent manner Will give vendors incentive to create

applications that support this


Why Standards? Why do we need standards?

– To make information universally available to users– facilitate sharing and interchange of information– To preserve information (make it safe from

changes in hardware and software) Standards only work if communities widely

accept them, but they’re necessary for communities to work together


Why are you Managing this Information?

Organizational mission & type Users Uses


Questions to Ask

What communities is this standard designed for? What type of information is this standard designed to

handle? What functions is this standard designed to serve? What previous standards is it built upon? Does the standard prescribe how to create new records (or

parts of records), or how to map from existing records? How far does the standard go? Semantics: Does it define

element sets? Rules? Syntax?-


What is Metadata

_ Structured data describing other data used to find or help manage information resources

_ Aids in interoperability_ Titles, dates, captions, cataloging and

indexing data, file headers, rights info, provenance, code books, transaction logs, ...

_ One person’s metadata is another’s data


Sorting through the Standards Morass

_ Data Structures (DC, CDWA, MARC, VRA Core, TEI, EAD, MESL data dict)

_ Data Interchange (Z39.50)

_ Data Values/vocabularies (LCSH, AAT, ULAN, TGN)

_ Data Content/syntax (AACR2)


Semantics/Syntax/Structure

_ Semantics– meaning, as defined by a community to meet their particular needs

(DC)

_ Syntax– a systematic arrangement of data elements for machine processing

– facilitates the exchange and use of metadata among various applications (HTML, XML, RDF)

_ Structure– a formal arrangement of the syntax with the goal of consistent

representation of the semantics (rules defining field contents like 1/11/99)


What is MetadataTypes & Uses

lots of different ways of dividing the clusters


Uses of Metadata

_ Discovery & Retrieval_ Identification/Provenance_ Rights Management_ Viewing_ Integrity_ Longevity_ Content rating


Containers and Packages of Metadata

Warwick, not MARC

_ modular_ overlapping_ extensible_ community-based_ designed for a networked world to aid

commonality btwn communities while still providing full functionality within each community


Some different schemes where Metdata is kept

_ embedded withing the object (HTML tags)_ in a separate related DB maintained by same

organization (OPAC, MOA II)_ in a separate DB maintained by a separate

organization (Books in Print, ratings systems)

_ derived on-the-fly from a different scheme (MARC-to-DC)


Collaborative Metadata Projects

Dublin Core NSF/ERCIM Digital Collaboratory OCLC CORC Project- Visual Resources Association (VRA) Core Encoded Archival Description (EAD) Computerized Interchange of Museum Information

(CIMI)- Records Export for Art and Cultural Heritage

(REACH)


Dublin Core (3/95)

_ improve resource discovery_ anticipate precision problems of Web Crawler-

based searching tools_ existing metadata could be “dumbed down”_ elements should be simple to understand and use,

so that any individual should be able to assign terms him/herself

_ software might eventually automatically generate very base-level metadata


Dublin Core

Title Creator Subject Description Publisher Contributors Date Type

Format Identifier Source Language Relation Coverage Rights


Dublin Core

every element is both optional and repeatable elements are cross-disciplinary elements are extensible by organized communities can employ a syntax such as html’s

<META> tagset for use by Spiders and HarvestersMay 2000 DLF Metadata Harvesting Project


DC Qualifiers

_ allows one community to express important nuances and qualifications, while still making the basic importance available to communities with simple needs

_ our community can reflect alternate title, transliterated title, and main title, yet they will all be found under a simple Web search under “title”


Discovery Metadata:Recent History

_ Dublin Core (3/95)_ Warwick Framework (4/96)_ Image Metadata Workshop (9/96)_ Canberra, Helsinki, ... DC (98)_ Digital Library Collaboratory (97-)_ DC-8, Frankfurt 10/99


Dublin Core--further work

_ Warwick Framework– metadata packages for extensible functions

– layed groundwork for RDF

_ Canberra Qualifiers– refining the semantics of the element set to provide more precise info

– SUBELEMENT, SCHEME, LANG

_ Granularity– no hierarchical relationships w/i a given DC record; only one record

per discrete object (collection or item-level), and relationship field plus qualifier links them

The Research Process and Functional Categories of

Metadata_ Discovery_ Retrieval_ Collation_ Analysis_ Re-presentation


Metadata Mapping-

Crosswalks Resource Description Framework (RDF)


Crosswalks

mapping btwn differing metadata structures eliminate the need for monolithic,

universally adopted standards focus on flexibility and interoperatiblity RDF-based metadata registries


Crosswalk ExampleCDWA Object ID

CIMISchema

FDAVRA CoreCategories

USMARCDUBLINCORE

OBJECT/WORK (core)

DocumentClassification-CatalogLevel (core)DocumentClassification-Group Type

Object/Work-Type (core)

Type ofObject

objectNAME DocumentClassification- DocumentType (core)Purpose-Purpose(Broad) (core)Purpose-Purpose(Narrow)

W1. WorkType

655 Genre-Form

Type

Object/Work-Components

quantity DocumentClassification-Extent

300a PhysicalDescription-Extent

ORIENTATION/ARRANGEMENT

Description

TITLES ORNAMES(core)

Title objectTitlebibliographicTitle

Group/ItemIdentification-RepositoryTitleGroup/ItemIdentification-DescriptiveTitle (core)Group/ItemIdentification-InscribedTitle

W2. Title 24Xa Titleand Title-RelatedInformation

Title


Resource Description Framework (RDF, spec released 2/99)

_ W3C Metadata activity_ designed to move the Web beyond simple links to

semantically-rich relationships btwn resources_ metadata application using XML as a common syntax for

exchange and processing_ flexible architecture for managing diverse application-

specific metadata packets that can be processed by machines_ associates resources, property types, and corresponding

values_ http://www.w3.org/RDF/


RDF

_ Resources (character strings, names, digital objects)

_ Property (“is the author of”)_ Value

_ resources+properties=relationships_ many different relationships can be reflected


XML-encoded RDF

_ <?xml:namespace ns=http://www.w3.org/RDF/RDF prefix="RDF" ?>

_ <?xml:namespace ns=http://purl.oclc.org/DC/ prefix="DC" ?>

_ <RDF:RDF>_ <DC:Creator>Howard Besser</DC:Creator>_ </RDF:Description>_ </RDF:RDF>


Should you start building with RDF today?

_ Tools are primitive_ Standard still likely to evolve


Metadata for Digital LibrariesHoward Besser

UCLA School of Education & Information

Baca, Murtha (ed). Introduction to Metadata, Los Angeles: Getty Information Institute, 1998

http://www.getty.edu/gri/standard/intrometadata/

http://sunsite.Berkeley.EDU/Imaging/Databases/#standards

http://sunsite.Berkeley.EDU/moa2/

http://sunsite.Berkeley.EDU/Longevity/

http://www.ifla.org/II/metadata.htm

http://purl.oclc.org/metadata/dublin_core/

http://purl.oclc.org/corc/

http://lcweb.loc.gov/ead/

http://www.gseis.ucla.edu/~howard/image-meta.html

http://www.gseis.ucla.edu/~howard/Metadata/UC-May00/

http://sunsite.berkeley.edu/Metadata/sp2000.html

Dublin Core Metadata

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