1. Pete Johnston & Andy Powell, Eduserv Foundation pete.johnston@eduserv.org.uk andy.powell@eduserv.org.uk www.eduserv.org.uk/foundation 28 June 2006 Update on work of Joint DCMI/IEEE LTSC Task Force CETIS Metadata & Digital Repositories SIG, UKOLN, Bath

2. 28 June 2006CETIS MDR SIG, Bath2 Background Metadata standards typically developed to support requirements of some community or domain Resources used across community/domain boundaries Implementers want –to use component parts of different standards in combination –to (re)use components of other implementers ’ work Concept of “ metadata application profile ” (e.g. Heery/Patel, Duval et al) –tailor standard to context –combine components from different standards ( “ mix & match ” )

3. 28 June 2006CETIS MDR SIG, Bath3 Abstract Models for Metadata Abstract Model of metadata standard specifies –Nature of components and constructs used in standard –Set of rules for building abstract information structure IEEE LOM Abstract Model –AIS = LOM instance –Data elements containing other data elements – “ Leaf ” data element values associated with datatypes (how value spaces interpreted) DCMI Abstract Model –AIS = DC description set –Description = set of statements about resource –Statement references to property, value, vocabulary encoding scheme, syntax encoding scheme value strings, value representations

4. 28 June 2006CETIS MDR SIG, Bath4 Abstract Models & Application Profiles Both DC and LOM have notions of “ metadata application profile ” … … but based on respective Abstract Model DC Application Profile –how to use a set of identified properties, vocabulary encoding schemes, syntax encoding schemes to construct a DC metadata description set LOM Application Profile –how to use a set of identified LOM data elements, datatypes, vocabularies to construct a LOM instance –LOM conceptual data schema includes AM and a “ base ” application profile

5. 28 June 2006CETIS MDR SIG, Bath5 Abstract Models & Bindings for Metadata Abstract Models are syntax-independent Bindings describe –how abstract information structure is serialised/encoded in a metadata format –how instances of a metadata format are interpreted in terms of abstract information structure Both DC & LOM have bindings to XML formats However, formats interpreted in terms of different Abstract Models –e.g. XML element parent-child relationships have different interpretations in LOM-XML and DC-XML

6. System A DC Description Set DC-XML Instance Encode using Binding Construct using DCAM & DCAP Decode using Binding DC Description Set Interpret using DCAM System B DC-XML Instance

7. System A Encode using Binding Construct using LOM AM & LOM AP Decode using Binding Interpret using LOM AM System B LOM Instance LOM-XML Instance

8. 28 June 2006CETIS MDR SIG, Bath8 The problem IEEE LOM standard and Dublin Core based on different Abstract Models LOM data elements and DC properties/classes can not be used in combination in same information structure Earlier work on DC-LOM interoperability focused on RDF –mapping LOM to RDF –mapping DC to RDF Not generalisable to other DC formats

9. 28 June 2006CETIS MDR SIG, Bath9 The proposed solution Develop a LOM-DCAM mapping –“LOM data elements” => “instances of DCAM components/constructs” –Interpretation of LOM semantics in terms of DCAM Not a binding for LOM, but a translation –lossy in part –one-way translation Approach –conceptualise LOM as Entity-Relationship model build on earlier work for LOM RDF binding –represent E-R model in terms of DCAM constructs –specify required terms, assign URIs

10. LOM Conceptual Data Schema Dublin Core Abstract Model DC-RDF Instance DC-XML Instance conforms to bound to translate (lossy) bound to LOM Instance DC Description Set LOM-XML Instance DC Description Set Combined DC Description Set

11. 28 June 2006CETIS MDR SIG, Bath11 Outcomes View of LOM as a basic DC Application Profile Availability of set of “LOM terms” which are usable in other DCAPs Availability of RDF binding of LOM “for free” via DC RDF binding (mapping) Separation of LOM-DCAM translation from RDF binding First step towards better alignment of DC and LOM abstract models?

12. 28 June 2006CETIS MDR SIG, Bath12 Joint DCMI/IEEE LTSC Task Force Initiated at DC2005 in Madrid, Sep 2005 Reports to DC Education WG & IEEE LTSC Chairs: Mikael Nilsson & Jon Mason Participation open to all: –mailing list (~20 subscribers), Wiki Joint: –Collaborative work on drafts –Joint consensus –Co-publishing of results Aim: an IEEE “Recommended Practice” and a DCMI “Recommendation”

13. 28 June 2006CETIS MDR SIG, Bath13 Joint DCMI/IEEE LTSC Task Force Charter approved by DCMI Advisory Board and IEEE LTSC SEC Draft PAR Scope & Purpose presented to LOM WG (March 2006) Three initial outputs available for discussion: 1.Draft of LOM-DCAM mapping –includes description of DCAP 2.Example instance based on mapping –LOM XML –DC Text 3.Draft of required property/class/value definitions –folllowing DC “Schema Model”/Usage Board conventions

14. LOM-XML DescriptionSet ( Description ( ResourceURI ( ) Statement ( PropertyURI ( dc:title ) ValueString ( “ Wilfred Owen and Realism ” Language ( en-GB ) ) Statement ( PropertyURI ( dc:language ) ValueString ( “ en-GB ” SyntaxEncodingSchemeURI ( dcterms:RFC3066 ) ) Statement ( PropertyURI ( lom:keyword ) VocabularyEncodingSchemeURI ( a:NLS ) ValueString ( "Owen, Wilfred" Language ( en-GB ) ) URI http://purl.org/poi/rdn.ac.uk/12345- 67890 Wilfred Owen and Realism en-GB Owen, Wilfred DC-Text

15. 28 June 2006CETIS MDR SIG, Bath15 Other related DCMI work Expressing DC metadata using XML –Working Draft for public comment (June 2006) –Revised XML binding for DC Expressing DC metadata using RDF –Working Draft for public comment (June 2006) –Mapping from DCAM to RDF DC-Text: A Text Syntax for DC metadata –Under discussion by DC Architecture WG Updating of DCMI term definitions –Under discussion by DC Usage Board

16. 28 June 2006CETIS MDR SIG, Bath16 Next steps Verify mapping through more examples –Identify points of loss-iness Finalise mapping Finalise terms, definitions, URIs Finalise DCAP Special Session at DC2006 (October, 2006, Colima, Mexico) Prepare docs for formal review/publication Feed into DC Education WG work on DC Ed AP Feed into IEEE LTSC work on “next generation” LOM

17. 28 June 2006CETIS MDR SIG, Bath17 Joint DCMI/IEEE LTSC Task Force http://dublincore.org/educationwiki/DCMIIEEELTSCTaskforce

18. Pete Johnston & Andy Powell, Eduserv Foundation pete.johnston@eduserv.org.uk andy.powell@eduserv.org.uk www.eduserv.org.uk/foundation 28 June 2006 Update on work of Joint DCMI/IEEE LTSC Task Force CETIS Metadata & Digital Repositories SIG, UKOLN, Bath