Harmony project - JISC Synthesis meeting 2001

Http://ilrt.org/discovery/harmony/ 1

ILRT / Harmony / JISC Synthesis

Dan Brickley, ILRT.University of [email protected]

Harmony and Synthesis



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



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



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



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.”(!)



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)



We implemented it...



ABC at a glance



Query syntaxSELECT ?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/



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



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



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”



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



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•



ABC in context (1999-2000)

• The Metadata wars

• domain overlaps

• Warwick Framework (myth...)

• “Extensibility”, “qualifiers...”

• Multimedia (*) metadata



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”



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



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)



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



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)



Questions...



data merging / namespace mixing