The Harmony collaboration led to a metadata model and query implementation that supports resource discovery over multimedia metadata descriptions. Key aspects include extending Dublin Core for multimedia, modeling complex cases like versioning and alternate formats, and proposing a common approach. The ABC model was implemented to address metadata challenges and allows querying across namespaces. Lessons learned include issues with project scope and coordination across distributed teams.

1. Harmony and Synthesis Dan Brickley, ILRT. University of Bristol [email_address]

2. Harmony project overview Who? Dan Brickley, Libby Miller (ILRT) Carl Lagoze (Cornell) Jane Hunter (DSTC) What we’re trying to do: simple vs complex multimedia metadata; ABC; Progress: milestones and successes Challenges and lessons learned

3. Project Partners Instititute for Learning and Research Technology (ILRT), University of Bristol Cornell University, USA (NSF funded) DSTC (self-funding partner) common background: metadata, digital images, Dublin Core, XML, RDF, extensibility architectures

4. Harmony: original goals Extend Dublin Core for multimedia Model ‘problematic’ cases versioning (document workflow) alternate manifestations (formats, conversions) content of composite media objects cross domain: education + media + medicine Propose cheap common approach

5. What have we been doing? “ The Harmony collaboration has led to a metadata representational model (aka ontology, vocabulary, schema) and XML/RDF query implementation (query language and database search system) that supports resource discovery applications over multi-media, multi-vocabulary metadata descriptions.”(!)

6. In a nutshell... Metadata headaches, 1995-1999: “ works / manifestations; objects, their depictions and creators; agents, actions, change and versioning...” (everyone knew metadata could get complicated)

7. We implemented it...

8. ABC at a glance

9. Query syntax SELECT ?event, ?type, ?time, ?place FROM http://ilrt.org/discovery/harmony/oai.rdf WHERE (web::type ?event abc::Event) (abc::context ?event ?context) (dc::type ?event ?type) (abc::time ?context ?time) (abc::place ?context ?place) USING web FOR http://www.w3.org/1999/02/22-rdf-syntax-ns# abc FOR http://ilrt.org/discovery/harmony/abc-0.1# dc for http://purl.org/dc/elements/1.1/

10. Implementation: Ongoing development of ABC (NSF and DELOS funded workshops) Testbed collaboration with CIMI Prototype query language (‘Squish’) Software: query engine and database Implementation feeds into ABC model collaboration focus on metadata model

11. Implementation(2) Acronyms: XML, RDF, W3C, DARPA/DAML, MPEG, CIMI, RSS, OAI, DELOS (dig-lib and beyond...) Testbed data: CIMI (museums, images...), OAI archives, RSS feeds Schema language convergence (XML/RDF Schema, DAML) opensource’d software: Java, Perl

12. Example RDF/XML Queries “ Find resources whose dc:format is audio/mp3 , whose dc:rights is http://opencontent.org/opl.shtml and which were the output of an abc:CreationEvent involving an agent who works for the department whose home page is http://www.cs.cornell.edu ”

13. Was that a ‘multimedia’ query? Multi-media content focusses our attention on mixing content from diverse contexts multi-media content requires combination of descriptive techniques multi-media data isn’t a world apart avoid mm-specific technology if we can

14. Recap: solving which problem? Q: What has this got to do with multimedia ? (“scope creep”?) A: The scope creep problem! ABC and Harmony are a response to the ‘metadata wars’ (DC/Education/INDECS/multimedia) ...and the too many committees problem

15. ABC in context (1999-2000) The Metadata wars domain overlaps Warwick Framework (myth...) “ Extensibility”, “qualifiers...” Multimedia (*) metadata

16. Harmonisation using ABC Define some ‘abstract, basic concepts’ A common representational style Supports vocabulary mixing XML/RDF encoding for exchange Focus on events, agents, relationships MPEG-7 RDF encoding by DSTC “ putting the multi in multimedia”

17. Current Activity Ontology Harmonisation w/shop findings Preparing a 2nd DELOS w/shop OAI and RDF/RSS interoperability Refining the model: representing events and states (accurate versioning audit trail) Track model with implementations

18. Project Management issues initial (too) tightly-coupled project plan Staffing (p/t PI as uk project manager) UK/US/Australia: timezones, travel identifying common ground (ABC) Evaluation: difficult for metadata formats (usage measures? Encourage adoption) dissemination (groundwork in place)

19. Lessons for DNER Metadata modularity is hard Technology in this area immature Standards: expensive to invest in; expensive to ignore Semantic Web and DNER: wider computing industry landscape important The scope problem may have technical as well as social/political aspects

20. Lessons(2)... Data formats not protocols; schemas not RPCs OAI and RSS 1.0, the two largest initiatives in this tradition, both developed with Harmony involvement, are maturing fast. Cheap technology. Tech complexity relates to staffing issues (file formats vs protocols)

21. Questions...

22. data merging / namespace mixing