29
May 2
00
7
Pete Johnston, Eduserv [email protected]
www.eduserv.org.uk/foundation
Some thoughts on Compound Objects & Graphs
OAI ORE Technical Committee Meeting, New York City
29 May 2007OAI ORE Technical Committee Meeting, New York City, USA
2
Some thoughts on Compound Objects & Graphs
• Graph or graphs?
• So which graph do I need?
Title slide photo of Brooklyn Bridge by Flickr user smcgeeSee http://www.flickr.com/photos/smcgee/351136186/
29 May 2007OAI ORE Technical Committee Meeting, New York City, USA
3
Graph or graphs?
part part
Composite X
Document A Document B
Doc-AHTML
Doc-APDF
view
view Doc-B
HTML
view
partpart
Document C Document D
view
view
view
view
Doc-CHTML
Doc-CPDF
Doc-DHTML
Doc-DPDF
ore:hasView
ore:hasView
Composite:X
http://example.org/graph/1
Graph 1?
Doc:A
Doc:D
Doc:B
ore:hasPart
ore:hasPart
Doc:AHTML
ore:hasView
ore:hasView
ore:hasPartDoc:C
Doc:APDF
Doc:BHTML
ore:hasView
ore:hasPart
Doc:CHTML
ore:hasView
Doc:CPDF
Doc:DHTML
ore:hasView
Doc:DPDF
ore:hasView
ore:hasView
Composite:X
http://example.org/graph/2
Graph 2?
Doc:A
Doc:D
Doc:B
ore:hasPart
ore:hasPart
Doc:AHTML
ore:hasView
ore:hasView
ore:hasPartDoc:C
Doc:APDF
Doc:BHTML
ore:hasView
ore:hasPart
Doc:CHTML
ore:hasView
Doc:CPDF
Doc:DHTML
ore:hasView
Doc:DPDF
ore:hasView
ore:hasView
Composite:X
http://example.org/graph/3
Graph 3?
Doc:A
Doc:D
Doc:B
ore:hasPart
ore:hasPart
Doc:AHTML
ore:hasView
ore:hasView
ore:hasPartDoc:C
Doc:APDF
Doc:BHTML
ore:hasView
ore:hasPart
Doc:CHTML
ore:hasView
Doc:CPDF
Doc:DHTML
ore:hasView
Doc:DPDF
Composite:X Composite:Yore:isPartOf
http://example.org/graph/4
…and Graph 4? (different creator/authority/provenance?)
Composite:Y Composite:Xore:hasPart
http://example.org/graph/5
…or Graph 5?
29 May 2007OAI ORE Technical Committee Meeting, New York City, USA
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So which graph do I need?
29 May 2007OAI ORE Technical Committee Meeting, New York City, USA
11
Compound objects and graphs
• Compound object and graph are distinct resources, identified by distinct URIs
• Single object - multiple graphs?– Different purposes/contexts?
• Graph discovery– Links in representation of object (in HTTP header or in e.g. HTML)– Content negotiation– (Sitemaps etc)
• If multiple graphs may be provided then– “Provider” can’t depend on serving single graph as representation of
object?– But could serve “graph list”?
• If multiple graphs provided, how does consumer decide which graph to use?
– Metadata describing graph?
29 May 2007OAI ORE Technical Committee Meeting, New York City, USA
12
Examples etc
• Examples– http://www.incognitum.net/petej/projects/oaiore/e
xamples/20070521/
• e.g. Doc 2– http://www.incognitum.net/petej/projects/oaiore/e
xamples/20070521/doc2/
• Berners-Lee’s Tabulator– http://dig.csail.mit.edu/2005/ajar/ajaw/tab
• Dave Beckett’s Triplr– http://triplr.org/rdf/http://www.incognitum.net/pet
ej/projects/oaiore/examples/20070521/doc2/
29
May 2
00
7
Pete Johnston, Eduserv [email protected]
www.eduserv.org.uk/foundation
Some thoughts on Compound Objects & Graphs
OAI ORE Technical Committee Meeting, New York City
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