1. A centre of expertise in digital information management www.ukoln.ac.uk UKOLN is supported by: XML and the DCMI Abstract Model DC Architecture WG Meeting, DC-2005, Madrid, Spain, Monday 12 September 2005 Pete Johnston Research Officer, UKOLN, University of Bath www.bath.ac.uk

2. A centre of expertise in digital information management www.ukoln.ac.uk DCMI Abstract Model and Bindings DCAM describes conceptual model for DC metadata description set –types of construct –relationships between constructs Description sets encoded/serialised as records Binding describes mapping between constructs in conceptual model to components in syntax Two way –encoding application: description set -> record –decoding application: record -> description set

3. A centre of expertise in digital information management www.ukoln.ac.uk DCMI Abstract Model and XML DCMI provides multiple "encoding guidelines" specifications –XHTML, RDF (Simple, Qualified), XML Guidelines for implementing Dublin Core in XML (2003) –DCMI Recommendation XML binding for DC metadata Mapping between constructs in conceptual model to components in XML syntax –XML elements (names, content), –XML attributes (values) Other non-DCMI XML bindings for DC deployed

4. A centre of expertise in digital information management www.ukoln.ac.uk DC-XML-2003 and DCMI Abstract Model DCAM Appendix C –features of DCAM supported by DC-XML-2003 However, DC-XML-2003 pre-dates DCAM –maps conceptual models to XML but does not map DCAM to XML –provides own models "Simple DC Record" "Qualified DC Record DC-XML-2003 models different from DCAM

5. DC-XML-2003 models and DCMI Abstract Model (1) DC-XML-2003DCAM "record"description "property and associated value" statement "value"value string Same/similar concepts, different labels

6. DC-XML-2003 models and DCMI Abstract Model (2) DC-XML-2003DCAM resource URI value URI multiple value representations rich representations related descriptions description sets types of "record" Concepts present/omitted

7. DC-XML-2003 models and DCMI Abstract Model (3) DC-XML-2003DCAM "encoding scheme"vocabulary encoding scheme, syntax encoding scheme Concepts conflated

8. A centre of expertise in digital information management www.ukoln.ac.uk Problems Attempts to encode/decode conceptual constructs not present in DC-XML-2003 models –resource URI –value URI –vocabulary encoding scheme/syntax encoding scheme distinctions

9. A centre of expertise in digital information management www.ukoln.ac.uk DC-XML-2003 models and DC-XML-Binding (1) Syntax examples with no mapping to DC- XML-2003 models (section 6) –ODRL, IMS-LRM XML fragments –XML sub-tree constructed according to rules of second XML format –XML sub-tree has no interpretation in DC-XML- 2003 Contradicts rationale for specification –error in specification?

10. A centre of expertise in digital information management www.ukoln.ac.uk DC-XML-2003 models and DC-XML-Binding (2) Binding "encoding schemes" to XML Schema datatypes –XML Schema datatypes apply to XML element content, XML attribute values –syntax encoding schemes? –but default type always present? Datatype derivation problems –trying to introduce support for rich representations at syntax level

11. A centre of expertise in digital information management www.ukoln.ac.uk Problems Section 6 encourages merging of arbitrary XML fragments –hybrid document with no interpretation –"undermines" mapping to DCAM! Mapping "encoding schemes" to XML Schema complex types –can't work for both vocabulary encoding schemes and syntax encoding schemes –Complex Type derivation problematic for some tools

12. A centre of expertise in digital information management www.ukoln.ac.uk Proposal XML binding for DC explicitly based on DCAM –subset of DCAM? –full DCAM? including review of use of XML Schema datatyping Early drafts

13. A centre of expertise in digital information management www.ukoln.ac.uk Questions Stay with (extended) DC-XML-2003? –emphasise that supports simpler model? Maintain both (extended) DC-XML-2003 and DC-XML-2005? –emphasise that different models supported Deprecate DC-XML-2003 and move towards support for DC-XML-2005 only?

14. A centre of expertise in digital information management www.ukoln.ac.uk UKOLN is supported by: XML and the DCMI Abstract Model DC Architecture WG Meeting, DC-2005, Madrid, Spain, Monday 12 September 2005 Pete Johnston Research Officer, UKOLN, University of Bath www.bath.ac.uk