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A centre of expertise in digital information management www.ukoln.ac.uk UKOLN is supported by: IEMSR, the Information Environment & Metadata Application Profiles IEMSR Project Workshop, Bath Tuesday 15 March 2005 Pete Johnston Research Officer, UKOLN www.bath.ac.uk
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A centre of expertise in digital information management www.ukoln.ac.uk Metadata Schema Registry Application that provides services based on information about "metadata terms" and related resources "Metadata term" = "unit of meaning" deployed in metadata descriptions "Metadata terms" defined and managed as sets created for some functional requirement Related resources –aggregations of "metadata terms", guidelines, bindings etc
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A centre of expertise in digital information management www.ukoln.ac.uk Functions Services to human readers, software agents Disclosure of "terms" Discovery/selection of "terms" Discovery of relationships between "terms" –support for mapping, inferencing Verification of provenance/status of "terms" Pointers to related resources
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A centre of expertise in digital information management www.ukoln.ac.uk The problem with "terms" "Metadata terms" defined with reference to conceptual frameworks ("meta-models") Multiple frameworks/models exist Different aggregations of "metadata terms" reference different models/frameworks –possibly incompatible "Metadata terms" not necessarily directly comparable –must always consider framework
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A centre of expertise in digital information management www.ukoln.ac.uk The IEMSR and the IE
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A centre of expertise in digital information management www.ukoln.ac.uk The IEMSR and the IE Effective exchange of metadata essential to interoperability –IE Technical Standards specify "baseline" of Simple DC and/or UK LOM Core Serialised using specified XML bindings Use of metadata "application profiles" –Specification of how existing "metadata terms" deployed Also exchange of richer metadata –Introduction of new "metadata terms" Increasing requirement to disclose information about "metadata terms" –Issues of authority, currency, provenance, trust
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A centre of expertise in digital information management www.ukoln.ac.uk The IEMSR and the IE IEMSR as shared/infrastructural service –Machine interface(s) ("structured") However… metadata exchange in IE currently based on prior co-ordination between human data/service providers on metadata formats –limited extensibility? IEMSR also as presentational service –Human-readable interface ("unstructured") –Disclose/discover metadata semantics, usage –Promote appropriate reuse of existing solutions –Minimise duplication of effort "Metadata portal"
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JISC-funded content providers institutional content providers external content providers brokersaggregatorscataloguesindexes institutional portals subject portals learning management systems media-specific portals end-user desktop/browser presentation fusion provision OpenURL resolvers shared infrastructure authentication/authorisation (Athens) JISC IE service registry institutional preferences services terminology services user preferences services resolvers IEMSR (based on Andy Powell's JISC IE Architecture diagram)
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JISC-funded content providers institutional content providers external content providers brokersaggregatorscataloguesindexes institutional portals subject portals learning management systems media-specific portals end-user desktop/browser presentation fusion provision OpenURL resolvers shared infrastructure authentication/authorisation (Athens) JISC IE service registry institutional preferences services terminology services user preferences services resolvers IEMSR metadata portal (based on Andy Powell's JISC IE Architecture diagram)
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A centre of expertise in digital information management www.ukoln.ac.uk The IEMSR Project
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A centre of expertise in digital information management www.ukoln.ac.uk IEMSR project Primary outputs –Models for application profiles –Data creation tool(s) for DC & LOM implementers (plus documentation) –Pilot metadata schema registry service –Pilot Web site –Open-source software –Recommendations re policy framework
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A centre of expertise in digital information management www.ukoln.ac.uk IEMSR project Outcomes –Consensus on models for DCAP, LOMAP –Improved disclosure/discovery of metadata semantics –Foundation for richer services (mapping, inferencing etc) –Open-source software Benefits –Consistency in creating APs –Collaboration between LOM and DC communities –Wider access to/re-use of existing solutions –Reduced duplication of developer effort –Improved interoperability
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A centre of expertise in digital information management www.ukoln.ac.uk The IEMSR Architecture
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IEMSR Data Source
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IEMSR Registry Server IEMSR Web Site Other Presentational Service IEMSR Data Creation Tool Other Data Creation Tool API
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A centre of expertise in digital information management www.ukoln.ac.uk Metadata Application Profiles
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A centre of expertise in digital information management www.ukoln.ac.uk Metadata Application Profiles Implementers adopt metadata standards in pragmatic way –optimise for requirements of application Metadata "application profile" as declaration of usage –(re-)use of existing terms –constrained, customised for context of application But metadata standards based on different "meta- models", conceptual frameworks –Dublin Core: statement-based –LOM: hierarchical, ordered tree/set of containers
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A centre of expertise in digital information management www.ukoln.ac.uk DCMI Abstract Model DC metadata description as set of statements about a subject resource Each statement –describes a relationship between the subject resource and a second resource (value) –consists of a reference to a property a reference to a value (optionally) a reference to an encoding scheme All DC elements (and element refinements) are properties –related by (e.g.) refinement/subproperty relationships Metadata applications typically based on description sets –sets of descriptions of related resources
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Description Statement Resource URI Property URIValue URI Property URIValue string Property URIRich representation Resource URI Property URIValue URI Property URIValue string Property URIRich representation Description Set
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A centre of expertise in digital information management www.ukoln.ac.uk DC Application Profile "A Dublin Core Application Profile (DCAP) is a declaration specifying, at a minimum, which properties are used within a particular metadata application. Optionally, an application profile may describe how those properties have been constrained or adapted for particular purposes" Specifies which properties occur in a description set Does not define new properties –References ("uses") properties already defined DCAP as set of "property usages" http://www.ukoln.ac.uk/projects/iemsr/wp2/dcap/
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A centre of expertise in digital information management www.ukoln.ac.uk DCAP Property Usage Must reference ("use") exactly one property May provide additional documentation on interpretation of the property May provide an application-specific label May specify obligation for the use of statements referring to the property –(whether it is mandatory, optional, conditional) May specify constraints on the occurrence of statements referring to the property May specify constraints on the permitted values of the property, by specifying that they are instances of specified classes –(i.e. may specify "encoding schemes" for the property)
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Property DCAP Property Usage usesProperty usesAs EncodingScheme Class hasPropertyUsage m n 1 m1 Metadata Vocabulary hasTerm 1 m 1 m m
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A centre of expertise in digital information management www.ukoln.ac.uk Examples of DCAPs OAI-DC (Simple DC) Application Profile –"Simple DC" –15 properties of DCMES –All optional, all repeatable –Value strings RDN-DC Application Profile –Slightly richer –Additional properties from DC Terms, RDN Terms –Encoding Schemes RSLP CD –Multiple resource types
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A centre of expertise in digital information management www.ukoln.ac.uk LOM Model No explicit LOM abstract model IEEE LOM standard defines LOM instance as hierarchical tree/container structure LOM data element is component in hierarchy –aggregate LOM data elements –simple LOM data elements –related by containment relationships Each Simple LOM data element is associated with –LOM datatype –Value space Reference to a standard LOM Vocabulary
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A centre of expertise in digital information management www.ukoln.ac.uk LOM Application Profile "A LOM Application Profile (LOMAP) is a specification of how the information model described by the IEEE LOM standard is adopted to the requirements of a particular metadata application. It specifies which LOM data elements are used, provides information on how they are interpreted in the context of the application, and describes constraints on their occurrence. A LOMAP may specify the use of vocabularies to provide values for LOM data elements where the datatype in the LOM standard permits it, and it may specify taxonomies and classification schemes for use for specified 'purposes' with the LOM Classification data element." http://www.ukoln.ac.uk/projects/iemsr/wp2/lomap/
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A centre of expertise in digital information management www.ukoln.ac.uk LOM Application Profile LOM AP describes constraints on LOM tree structure –Subject to constraints in LOM standard –LOM Data Element != DC Element –LOM AP != DC AP LOM AP as set of data element usages A data element usage –may provide additional documentation on how the data element is interpreted –may specify obligation for the data element –may specify permitted number of occurrences for the data element
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A centre of expertise in digital information management www.ukoln.ac.uk LOM Data Element Usage For a aggregate LOM data element –“shall not define datatype and value space” For a simple LOM data element –“must retain datatype and value space” For a simple LOM data element of datatype Vocabulary –May extend the value space, by allowing values from one or more non-LOM vocabularies For the LOM Classification data element –must specify a purpose for the classification (from the LOM standard vocabulary) –may specify the use of one or more taxonomies for that specified purpose of classification
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Taxonomy LOM data element LOM data element usage uses LOMDataElement LOM aggregate data element usage LOM simple data element usage extends ValueSpace Non-LOM vocabulary Classification data element usage hasPurpose uses Taxonomy LOM Classification purpose m 1 m n mm 1 n LOMAP contains m 1 Vocabulary datatype element usage
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A centre of expertise in digital information management www.ukoln.ac.uk Examples of LOMAPs UK LOM Core –"Core" set to support disclosure/discovery /access/use of UK learning resources RDN LTSN LOM Application Profile –Disclosure/discovery/access/use –Record sharing between RDN and LTSN partners over OAI-PMH
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IEMSR Registry Server IEMSR Web Site IEMSR Data Creation Tool API query results Practical Session 1: IEMSR Web Site
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IEMSR Registry Server IEMSR Web Site API response data RDF Data Source IEMSR Data Creation Tool Practical Session 2: IEMSR Data Creation Tool
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A centre of expertise in digital information management www.ukoln.ac.uk UKOLN is supported by: IEMSR, the Information Environment & Metadata Application Profiles IEMSR Project Workshop, Bath Tuesday 15 March 2005 Pete Johnston Research Officer, UKOLN www.bath.ac.uk
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