Post on 19-Jan-2015
description
Http://ilrt.org/discovery/harmony/ 1
ILRT / Harmony / JISC Synthesis
Dan Brickley, ILRT.University of Bristoldanbri@bris.ac.uk
Harmony and Synthesis
Http://ilrt.org/discovery/harmony/ 2
ILRT / Harmony / JISC 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
Http://ilrt.org/discovery/harmony/ 3
ILRT / Harmony / JISC Synthesis
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
Http://ilrt.org/discovery/harmony/ 4
ILRT / Harmony / JISC Synthesis
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
Http://ilrt.org/discovery/harmony/ 5
ILRT / Harmony / JISC Synthesis
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.”(!)
Http://ilrt.org/discovery/harmony/ 6
ILRT / Harmony / JISC Synthesis
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)
Http://ilrt.org/discovery/harmony/ 7
ILRT / Harmony / JISC Synthesis
We implemented it...
Http://ilrt.org/discovery/harmony/ 8
ILRT / Harmony / JISC Synthesis
ABC at a glance
Http://ilrt.org/discovery/harmony/ 9
ILRT / Harmony / JISC Synthesis
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/
Http://ilrt.org/discovery/harmony/ 10
ILRT / Harmony / JISC Synthesis
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
Http://ilrt.org/discovery/harmony/ 11
ILRT / Harmony / JISC Synthesis
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
Http://ilrt.org/discovery/harmony/ 12
ILRT / Harmony / JISC Synthesis
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”
Http://ilrt.org/discovery/harmony/ 13
ILRT / Harmony / JISC Synthesis
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
Http://ilrt.org/discovery/harmony/ 14
ILRT / Harmony / JISC Synthesis
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•
Http://ilrt.org/discovery/harmony/ 15
ILRT / Harmony / JISC Synthesis
ABC in context (1999-2000)
• The Metadata wars
• domain overlaps
• Warwick Framework (myth...)
• “Extensibility”, “qualifiers...”
• Multimedia (*) metadata
Http://ilrt.org/discovery/harmony/ 16
ILRT / Harmony / JISC Synthesis
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”
Http://ilrt.org/discovery/harmony/ 17
ILRT / Harmony / JISC Synthesis
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
Http://ilrt.org/discovery/harmony/ 18
ILRT / Harmony / JISC Synthesis
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)
Http://ilrt.org/discovery/harmony/ 19
ILRT / Harmony / JISC Synthesis
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
Http://ilrt.org/discovery/harmony/ 20
ILRT / Harmony / JISC Synthesis
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)
Http://ilrt.org/discovery/harmony/ 21
ILRT / Harmony / JISC Synthesis
Questions...
Http://ilrt.org/discovery/harmony/ 22
ILRT / Harmony / JISC Synthesis
data merging / namespace mixing