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The MEG Metadata Schemas Registry. Pete Johnston, Research Officer (Interoperability), UKOLN, University of Bath p.johnston@ukoln.ac.uk UKOLN Staff Seminar Bath, 25 June, 2003. The MEG Registry. Metadata schemas registries MEG & the MEG registry The MEG registry data model.
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The MEG Metadata Schemas Registry Pete Johnston, Research Officer (Interoperability), UKOLN, University of Bath p.johnston@ukoln.ac.uk UKOLN Staff Seminar Bath, 25 June, 2003
The MEG Registry • Metadata schemas registries • MEG & the MEG registry • The MEG registry data model
Metadata Schemas Registries • What is a metadata schemas registry? • Application that provides access to information on metadata vocabularies, their components, and related resources • What is a metadata schemas registry for? • Disclosure/discovery/selection • Navigation of relationships • For various purposes…. • "publication", convergence, tool support…. • For human readers & software agents
Metadata for Education Group (MEG) • Facilitated by Interoperability Focus • Forum for discussing provision of educational resources at all levels across UK • Encourage consistency of approaches to description • Use of DESIRE registry, 2000-2002 • Disclosure, implementation/localisation, "convergence"
MEG Registry Project • Funded by JISC/BECTa, 2002 • Re-engineering of DESIRE registry as RDF application • Shaped by work in SCHEMAS project • Some refinement of data model • Uses RDFS, but not (currently) OWL • Developed by Dave Beckett (server – Perl, Redland), Damian Steer (client – Java, Jena)
MEG Schemas Registry • Reads machine-readable descriptions of metadata vocabularies • descriptions stored in Schemas (RDF/XML) • publication API (HTTP POST) • also admin interface (HTTP GET) • Indexes those descriptions • Provides browse/search interfaces for • human readers (HTML) • software tools • query API (HTTP GET) http://meg.ukoln.ac.uk/
Vocabulary managers OtherApplications (including other Registries) Information seekers MEGClient Webbrowser RDF/XML (Schemas) RDF/XML (Schemas) RDF/XML RDF/XML Upload API (HTTP POST) Query API (HTTP GET) HTML browseinterface Database MEG Registry (Server)
The registry data model • A simplification of complexity • Based on • Dublin Core "Grammatical Principles" • Elements • Element Refinements • Encoding Schemes • "Application Profile" • May "use" elements from multiple element sets • May specify obligation/cardinality • May specify encoding schemes • May narrow "standard" element semantics
m 1 1 1 1 m m m m m 1 m m 1 1 m m 1 m m Agency Element Set Element Encoding Scheme Value Element Usage AppProfile
rdf:Property A name given to the resource http://purl.org/dc/elements/1.1/title reg:isElementOf rdfs:comment rdf:type reg:uses reg:uses reg:uses reg:uses http://.../qualifieddc/title http://.../rslpcoll/title rdf:type rdfs:comment rdf:type reg:ElementUsage reg:ElementUsage The name of the collection reg:isUsageIn reg:isUsageIn
http://meg.ukoln.ac.uk/ 1. Registry browse menu
1. Create Application Profile description Add AP details Add AP descriptionto Schema
Drag Element To Profile 2. Create Element Usage description Search registry for“title” Elements
3. Create Element Usage description Add ElementUsage details Add Element Usage descriptionto Schema
4. Save Schema as RDF/XML File -- Save As
Confirm Finish 5. Submit Schema to Server Click to submit
Some issues • Is the registry data model generally useful? • Or too simple? Too DC-oriented? • Need Schemas in data model • Review registry vocabulary • DCMI schema updates • RDF datatyping • OWL - Rich metadata about properties • API is simple • To what extent can registry support non-RDF applications? (IEEE LOM in XML)
Acknowledgements • UKOLN is funded by Resource: the Council for Museums, Archives and Libraries, the Joint Information Systems Committee (JISC) of the UK higher and further education funding councils, as well as by project funding from the JISC and the European Union.UKOLN also receives support from the University of Bath where it is based. • http://www.ukoln.ac.uk/
The MEG Metadata Schemas Registry Pete Johnston, Research Officer (Interoperability), UKOLN UKOLN Staff Seminar Bath, 25 June, 2003