Metadata Schema Registries Metadata Application Profiles the Information

Metadata Schema Registries, Metadata Application Profiles, & the Information Environment JISC Development Team, London Monday 18 April 2005 Pete Johnston Research Officer, UKOLN is supported by: www. bath. ac. uk 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 • Functions might include – Disclosure/discovery of information about "terms" – Verification of provenance/status of "terms" – Discovery of relationships between "terms" • support for mapping, inferencing – Pointers to related resources • usage in metadata application profiles, guidelines for use, bbindings • Support for services to human readers, software agents A centre of expertise in digital information management www. ukoln. ac. uk

Data Source MSR

IEMSR project • Funded under JISC Shared Services programme, Jan 2004 – July 2005 – UKOLN, University of Bath – ILRT, University of Bristol • CETIS, Becta as "contributing partners" – advice, evaluation, assistance with liaison with users • External evaluators (ESYS) • Building on previous work in MEG Registry Project (JISC/Becta) http: //www. ukoln. ac. uk/projects/iemsr/ A centre of expertise in digital information management www. ukoln. ac. uk

IEMSR project • Primary outputs – – – Description of requirements Models for metadata application profiles Pilot metadata schema registry service Pilot Web site Data creation tool(s) for DC & LOM implementers (plus documentation) – Open-source software – Recommendations re policy framework 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) • 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 between applications A centre of expertise in digital information management www. ukoln. ac. uk

Metadata Application Profiles A centre of expertise in digital information management www. ukoln. ac. uk

Metadata Application Profiles • Metadata standards provide sets of "terms", defined to support some function – resource discovery, resource (re)use, preservation etc • Implementers adopt metadata standards in pragmatic way – optimise for requirements of application • Metadata "application profile" as declaration of usage – (re-)use of previously defined terms – customised for context of application – may reference "terms" from multiple sources A centre of expertise in digital information management www. ukoln. ac. uk

Examples • OAI-DC (Simple DC) Application Profile – – "Simple DC" 15 properties of DCMES All optional, all repeatable Value strings • RDN-DC Application Profile – Additional properties from DC Terms, RDN Terms – Encoding Schemes • RSLP CD – Multiple resource types A centre of expertise in digital information management www. ukoln. ac. uk

Examples • UK LOM Core – Usage of IEEE LOM 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 A centre of expertise in digital information management www. ukoln. ac. uk

The IEMSR and the IE 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 • Also exchange of richer/different metadata – use of additional metadata "application profiles" – introduction of new "metadata terms" • Increasing requirement to disclose information about new "metadata terms" – Issues of authority, currency, provenance, trust 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 – typically based on XML rather than on higher-level data models – limited/controlled extensibility? – no “unknown terms”? A centre of expertise in digital information management www. ukoln. ac. uk

IEMSR: Use Scenarios • Metadata creation tool accesses machinereadable description of selected application profile – – Obligation/occurrence constraints Human-readable documentation for help info/tool tips Controlled vocabularies/encoding schemes Schemas for bindings • Presentation service requires information on selected application profile – What labels to use in display of harvested records A centre of expertise in digital information management www. ukoln. ac. uk

JISC-funded content providers authentication/authorisation (Athens) institutional content providers external content providers JISC IE service registry ov is io brokers aggregators catalogues pr IEMSR n user preferences services indexes media-specific institutional portals subject portals learning management systems si Open. URL resolvers fu institutional preferences services on resolvers end-user desktop/browser pr es shared infrastructure en ta tio n terminology services (based on Andy Powell's JISC IE Architecture diagram)

The IEMSR and the IE • Presentational service based on data from IEMSR – Human-readable interface ("unstructured") • "Metadata portal" for the IE – Disclose/discover metadata semantics, usage – Promote appropriate reuse of existing solutions – Minimise duplication of effort A centre of expertise in digital information management www. ukoln. ac. uk

IEMSR: Use Scenarios • Content provision service provider discloses application profile – Constructs & publishes description, submits to registry • Metadata schema developer explores/(re-) uses existing implementation choices – Selects terms for reuse in new application profile – Concerns of status, provenance, trust • Researcher surveys existing usage of metadata standards – How terms used in practice (within domain, community, area) A centre of expertise in digital information management www. ukoln. ac. uk

JISC-funded content providers authentication/authorisation (Athens) institutional content providers external content providers JISC IE service registry ov is io brokers aggregators catalogues pr IEMSR n user preferences services indexes media-specific institutional portals subject portals learning management systems si Open. URL resolvers fu institutional preferences services on resolvers ta tio en end-user desktop/browser pr es shared infrastructure metadata portal n terminology services (based on Andy Powell's JISC IE Architecture diagram)

IEMSR Project : Progress to Date A centre of expertise in digital information management www. ukoln. ac. uk

IEMSR project: Progress • Investigation of user requirements – CETIS, Becta, – Curriculum Online/Tagging Tool, JORUM • Functional requirements document • Data models for DC AP, LOM AP – RDF binding for models • Registry server • Web site – Initial prototype; tabbed browse • Data Creation Tool • Workshop (March 2004) • Evaluation by ESYS A centre of expertise in digital information management www. ukoln. ac. uk

Metadata Application Profiles revisited A centre of expertise in digital information management www. ukoln. ac. uk

The trouble with "terms" • "Metadata terms" defined with reference to conceptual frameworks ("meta-models") • Multiple frameworks/meta-models exist • Different metadata standards reference different meta-models/frameworks – possibly incompatible • "Metadata terms" not necessarily directly comparable – must always take framework into account • Consider DC and LOM…. 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 consists of – a reference to a property – a reference to a value – (optionally) a reference to an encoding scheme • All DC "elements" are properties • Compatible with RDF model • Metadata applications typically based on description sets – sets of descriptions of related resources A centre of expertise in digital information management www. ukoln. ac. uk

DC Application Profile • Specifies which properties occur in a class of description sets • Does not define new properties – References ("uses") properties already defined • DCAP as set of "property usages" • May – provide additional documentation on interpretation of the property – provide an application-specific label – specify constraints on the occurrence of statements referring to the property – specify constraints on the permitted values of the property (i. e. "encoding schemes") 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 A centre of expertise in digital information management www. ukoln. ac. uk

LOM Application Profile • Specifies which LOM data elements are used in a class of LOM instances • May – provide additional information on how LOM Data Elements are interpreted in the context of the application – describe constraints on their occurrence – specify the use of vocabularies to provide values for LOM data elements where the datatype in the LOM standard permits – specify taxonomies and classification schemes for use for specified 'purposes' with the LOM Classification data element A centre of expertise in digital information management www. ukoln. ac. uk

DC AP v LOM AP • DC AP describes DC metadata description set • LOM AP describes constraints on LOM tree structure – Subject to constraints in LOM standard • LOM Data Element != DC Element • LOM AP != DC AP A centre of expertise in digital information management www. ukoln. ac. uk

The IEMSR Architecture & Tools A centre of expertise in digital information management www. ukoln. ac. uk

IEMSR Development • Software development by ILRT – Dave Beckett, Nikki Rogers, Simon Price – RDF used throughout • Registry server – Redland, My. SQL, Perl – REST interfaces, supporting SPARQL – redevelop as Java application using Jena? • Web Site – Java J 2 EE application – Apache Struts: Tiles, Java Beans • Data Creation Tool – Java application, Eclipse SWT+Jface libraries A centre of expertise in digital information management www. ukoln. ac. uk

IEMSR Registry Server API IEMSR Web Site Other Presentational Service IEMSR Data Creation Tool Other Data Creation Tool

IEMSR Data Creation Tool IEMSR Registry Server API data response IEMSR Web Site IEMSR Data Creation Tool RDF Data Source

A centre of expertise in digital information management www. ukoln. ac. uk

A centre of expertise in digital information management www. ukoln. ac. uk

Query registry server A centre of expertise in digital information management www. ukoln. ac. uk

Select property to use A centre of expertise in digital information management www. ukoln. ac. uk

Describe how property used in this DCAP A centre of expertise in digital information management www. ukoln. ac. uk

Query again; select again A centre of expertise in digital information management www. ukoln. ac. uk

Select encoding scheme A centre of expertise in digital information management www. ukoln. ac. uk

IEMSR Web Site IEMSR Registry Server API query results IEMSR Web Site IEMSR Data Creation Tool

View Agency

Browse Agency list

View DCAP

Browse Agency list

View Agency

View Metadata Vocabulary

View DCAP

Issues, challenges, thoughts A centre of expertise in digital information management www. ukoln. ac. uk

Issues, challenges, thoughts • Complexity of working with multiple meta-models – Not only an issue for IEMSR or AP developers, but for other applications working across LOM and DC metadata – Ongoing discussions between DCMI and IEEE LOM communities • "Validation" of LOM APs – TELCERT project • Centralised v distributed registry services – IEMSR as "semi-distributed" • Reads/indexes data distributed on Web • But single point of provision of service – Distributed model? – W 3 C work on RDF query languages, protocol A centre of expertise in digital information management www. ukoln. ac. uk

Issues, challenges, thoughts • Users of machine-oriented IEMSR interfaces • IEMSR and other shared services – IEMSR as component in JISC IE – used in combination with other components, including other shared services – e. g. "which services deploy DCAP D or binding B? " • IEMSR + IESR • Scope/policy issues – which standards/profiles/terms are "in scope"? – authority, status, provenance, trust – "who says what about what" A centre of expertise in digital information management www. ukoln. ac. uk

Metadata Schema Registries, Metadata Application Profiles, & the Information Environment JISC Development Team, London Monday 18 April 2005 Pete Johnston Research Officer, UKOLN is supported by: www. bath. ac. uk A centre of expertise in digital information management www. ukoln. ac. uk