The OAI-ORE based data model of Europeana and the Digital Public Library of America: implications for educational publishing

Dov Winer

MAKASH – Advancing ICT Applications in Education

The 8thJerusalem EVA/Minerva International Conference on Digitisation of Culture

• Educational content and publishing

• RDF Semantic Web: Linked Open Data

• OAI-ORE educational Open Publishing instance: FlatWorldKnowledge

Europeana Metadata: From ESE to EDM

• Precursor: ESE (Europeana Semantic Elements)– used in 2008 version of Europeana– represents lowest common denominator for object metadata

• convert datasets to Dublin-Core like standard– forces interoperability– major drawback: original metadata is lost

• EDM (Europeana Data Model) goals– preserve original data while still allowing for interoperability

Semantic Web representation

From the presentation EDM, Europeana Data Model by Guus Schreiber et al. June 2010

Linked Open Data

http://linkeddata.org

Linked Open Data Datasets on the Web: 10/2011

http://www.linkeddata.org

http://esw.w3.org/DataSetRDFDump

http://esw.w3.org/TaskForces/CommunityProjects/LinkingOpenData/DataSets/Statistics

Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. http://lod-cloud.net/

Over 31.7 billion RDF triples

The essence of RDF: the “triple”

Source: “The thirty minute guide to RDF and Linked Data”, by Ian Davis and Tom Heath

subjectproperty

value

October 2011:20 Million objects and many more coming in…

Europeana and DPLA Joint Announcement

EDM Europeana Data Model

Guus Schreiber

with input from Carlo Meghini, Antoine Isaac, Stefan Gradmann, Makx Dekkers et al. from Europeana V1

EDM requirements

1. Distinction between “provided object” (painting, book, program) and digital representation

2. Distinction between object and metadata record describing an object .

3. Allow for multiple records for same object, containing potentially contradictory statements about an object

4. Support for objects that are composed of other objects5. Standard metadata format that can be specialized6. Standard vocabulary format that can be specialized7. EDM should be based on existing standards – “not yes another standard” !

EDM basics

• OAI ORE for organization of metadata about an object– Requirements 1-4

• Dublin Core for metadata representation– Requirement 5

• SKOS for vocabulary representation– Requirement 6

OAI ORE, Dublin Core and SKOS together fulfil Requirement-7!

EDM representation: RDF standard

• Ovals are web resources with a URL• Arcs are properties linking resources to other resources or

to literals• Resources belong to classes• RDF model can be specialized using subclass and

subproperty definitions

Dublin Core

• EDM uses the latest version of DCMI Metadata Termshttp://dublincore.org/documents/dcmi-terms/

• Specified with an RDF model• Specialization of 15 original DC elements

dcterms:coverage dcterms:spatial dcterms:temporal

• Can be specialized itself– see requirement

SKOS: vocabulary publication on the Web

• W3C standardhttp://www.w3.org/TR/skos-primer/

• Adopted by large institutions such as Library of Congress• Specified with an RDF model• Can be specialized itself

dov.winer@gmail.com

SKOS Simple Knowledge ORGANIZATION SYSTEM thesauri, classifications, subjects, taxonomies, folksonomies,… controlled vocabulary

concepts are documented, linked, merged with other data, composed, integrated and published on the Web

CONCEPTS identified by URIs using RDF triples

natural language expressions to refer to concepts:skos: prefLabel [descriptor]skos: altLabel [synonims, acronyms, abbreviations]

SEMANTIC RELATIONSHIPS…broader and narrower conceptsbroader/narrower relationships assert that a concept is broader/narrower in meaning…concepts somehow related

SCHEMES compiled sets of concepts: ConceptScheme class and inScheme relationship to link a concept to a scheme

hasTopConcept relationship for the entry points of narrower/broader hierarchy

LINK schemes map concepts from different schemes using the propertiesexactMatch, broadMatch, narrowMatch and relatedMatch Apr 19, 2023

OAI OREOpen Archives Initiative Object Reuse & Exchange

• Specification:http://www.openarchives.org/ore/1.0/toc.html

• Primer:http://www.openarchives.org/ore/1.0/primer

• Specified with an RDF model• Four key notions (RDF classes)

– Object: the book/painting/program being described– Aggregation: organizes object information from a particular provider (museum,

archive, library) – Digital representation: some digital form of the object with a Web address – Proxy: the metadata record for the object

OAI ORE

From the OAI-ORE Primer

The Example - 1

31

The Example - 2

32

Aggregation organizes data of a provider

33

aggregation

digital representation

object

provenancemetadata

Proxy: metadata record for an object

34

proxy

objectmetadata

Multiple aggregations = multiple providers

35

aggregation of DMF

aggregation of Louvre

Europeana is “just” a special providerwith processed/enriched metadata

36

Europeanaaggregation

enrichedmetadata

landingpage

Advanced modeling in EDM

• See the documentation

• Relations between “provided” objects– Part-whole links for complex objects– Derivation and versioning relations

• Predefined classes for person, place, time and event• Here enters the Role (central) for Specialized Vocabularies

http://www.flatworldknowledge.com/#

Thank you!

dov.winer@gmail.com