Introduction to Dublin Core Metadata

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Introduction toDublin Core Metadata

Hannes EbnerKnowledge Management Research groupRoyal Institue of Technology (KTH), Sweden

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Dublin Core Metadata Initiative (DCMI)

http://dublincore.org

• General descriptive metadata• Dublin Core Abstract Model

– Information model independent of format

• 1998: Dublin Core Element Set 1.0, IETF RFC2413• 2000/2001/2003: EU/US/ISO recommendation/standard

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DCMI

• Metadata Terms and Element Sets• Resource: "Anything that has an identity"

– Ideal: URI for everything that is described

• Resource Model: each value is– physical (books, people, etc)– digital (documents, images, etc) or– conceptual (time, subjects, etc) entity

• Resource Model: built on top of the W3C Resource Description Framework (RDF)

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Interoperability

• Set of interoperable metadata standards• Used for metadata harvesting (OAI-PMH): requirement to

support DC• RSS 1.0: the most flexible feed format (not widely

adopted)

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Dublin Core Elements -Simple Dublin Core

identifier, creator, contributor, publisher, title, description, language, subject, coverage, format, type, date, relation, source, rights

• 15 elements• All optional• Repeatable• Domain independent• dc namespace

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DCMI Terms -Qualified Dublin Coreabstract, accessRights, accrualMethod, accrualPeriodicity, accrualPolicy, alternative, audience, available, bibliographicCitation, conformsTo, contributor, coverage, created, creator, date, dateAccepted, dateCopyrighted, dateSubmitted, description, educationLevel, extent, format, hasFormat, hasPart, hasVersion, identifier, instructionalMethod, isFormatOf, isPartOf, isReferencedBy, isReplacedBy, isRequiredBy, issued, isVersionOf, language, license, mediator, medium, modified, provenance, publisher, references, relation, replaces, requires, rights, rightsHolder, source, spatial, subject, tableOfContents, temporal, title, type, valid

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DCMI Terms -Qualified Dublin Core• DCMI Terms

• dcterms namespace

• Element refinements (more specific)

• Encoding schemes (recommended): controlled vocabularies or special format

• 55 elements and attribute/value pairs

Examples:

Language<dc:language>English (UK)</dc:language> vs<dcterms:language scheme="ISO 639-1">en-gb</dcterms:language>Date <dc:date>November 2nd, 2009</dc:date> vs <dcterms:date scheme="W3CDTF">2009-11-02</dcterms:date>

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Dublin Core in RDF

• DCAM maps easily into RDF (built on top of it)• Semantic Web and Linked Data• Combinable with e.g. OWL, SKOS, etc• Helps machines processing data by maintaining semantics

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Custom Extensions to DC

• Mappings to DC where possible• Thorough documentation necessary• Example: LOM and DCAM

– IEEE LTSC / DCMI Task Force draft for mapping LOM to DCAM

– First implementation by KTH– Used within Organic.Edunet

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Summary

• 15 metadata elements• More than 50 DCMI approved properties• Ideal for Semantic Web and Linked Data based

repositories• Custom mappings to DCAM possible

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Links

The Dublin Core Metadata Initiativehttp://dublincore.org

DCMI Metadata Basicshttp://dublincore.org/metadatabasics/

DCMI Metadata Termshttp://dublincore.org/documents/dcmiterms/

Joint DCMI/IEEE LTSC Taskforcehttp://dublincore.org/educationwiki/DCMIIEEELTSCTaskforce