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Re: Relationships in SKOS Schemes

From: Antoine Isaac <aisaac@few.vu.nl>
Date: Tue, 28 Nov 2006 08:56:23 +0100
Message-ID: <456BEBA7.7060608@few.vu.nl>
To: Sean Bechhofer <sean.bechhofer@manchester.ac.uk>
CC: SWD WG <public-swd-wg@w3.org>

Another important point

>
> The SKOS Core Guide described the notion of concept schemes:
>
> http://www.w3.org/TR/swbp-skos-core-guide/#secscheme
>
> [[
> Usually, concepts are defined in relation to other concepts, as part
> of an internally coherent concept scheme. As mentioned in the
> introduction, a 'concept scheme' is defined here as: a set of
> concepts, optionally including statements about semantic relationships
> between those concepts.
> ]]
>
> How might I represent the fact that the semantic relationships between
> concepts occurs within a particular scheme? If my graph contains more
> than one vocabulary or concept scheme, how do you tell which scheme
> the relationships belong to?  If I understand things correctly, we can
> make assertions that a particular concept is in a scheme through the
> inScheme property, but this doesn't cover the semantic relationships
> themselves. In fact I don't see any way of doing this without
> resorting to reification....


And you are right. Relying on existing semantic web technologies, SKOS 
cannot offer more than what these technologies enable (at least if we 
want to keep relationships tractable for knowledge engineers, and 
perhaps also tools)
Note that a few patterns accounting for some kind of reification were 
already proposed, as in
http://www.w3.org/TR/2005/WD-swbp-skos-core-guide-20050510/#secdocnodestyle

>
> The notion of "containment" or "what's in the ontology" was one of the
> things that I found most unsatisfactory about working with OWL. In the
> RDF serialisation, there's no formalised notion of the ontology itself
> (in terms of which axioms occur within it) -- the best one can do is
> look and see whether the axioms are in an RDF graph that happened to
> contain an ontology tag. Not exactly ideal, and leads to various
> horrors when using imports.
>
> Have I missed something?


No!

Antoine
Received on Tuesday, 28 November 2006 08:49:07 GMT

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