Transcript Semantic Web Standards

CORES Metadata
Interoperability Workshop
Dave Beckett
SWAD-Europe
1
Dave Beckett - Background
• Metadata - DCMI
• Semantic Web - RDF Core
• Web Developer
• W3C Advisory Committee Rep.
2
W3C and Elements / Terms
• W3C is not a registry (defer to
IETF)
• Terms are in specifications
• Semantic web languages - URIs
• URIs not necessarily for retrieval
• Working with IETF on URI updates
3
Our standard has "elements"
• Few W3C RECs are languages
• Some have “elements” called:
– RDF: Properties, Classes
– XML: Infoitems, Facets, Particles (XSD)
• For those: Yes
4
Identified in a citable way
• “In principle, we would be willing to
identify our elements in a more
generalized form shared by other
standards as well.”
• Yes - part of the W3C mission
5
Identify elements with URIs
• Yes (RDF, OWL do this)
• But XSD uses XML Qnames
• Working on the latter
• Something may be behind the URI
(after resolution, retrieval)
6
URI stability, persistence, …
• Yes.
• Guaranteed by W3C host
institutions - Persistence Policy
• /TR/ document publication policy
• URIs for W3C namespaces policy
(2001)
7
Application Layer
• Mostly left to users
• Applications of RDF:
– Ontology Web Language (OWL)
– CC/PP
– WAI Content Guidelines
• Applications of XML Schemas:
– Few
8
W3C Semantic Web Activity
• Welcomes this initiative
• Encourage use of others terms
• Want to mix and match
• RDF bootstraping this with DCES
• Ontology Web Language (OWL)
9
URI Considerations
• URI schemes very expensive to
deploy.
• URNs getting cheaper - discovery
of resolution services by DDDS
• HTTP URLs very cheap
• URIs do not require being online
10