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RE: SKOS to RDFS/OWL ontology mapping

From: Bernard Vatant <bernard.vatant@mondeca.com>
Date: Tue, 14 Jun 2005 19:44:29 +0200
To: "Miles, AJ \(Alistair\)" <A.J.Miles@rl.ac.uk>, <public-esw-thes@w3.org>
Cc: "Dan Brickley \(E-mail\)" <danbri@w3.org>
Message-ID: <GOEIKOOAMJONEFCANOKCOEOFGCAA.bernard.vatant@mondeca.com>

Hi Alistair

> I like your usage scenarios, they'll be really useful when trying to write this up.
> > A subject in Topic Maps in just that unameit. Define a topic
> > of which subject is this
> > unameit, of which both eg:People and foaf:Person are
> > *occurrences*, with
> > "a:defined-by-OWL" and "a:defined-by-SKOS" as their
> > respective occurrence types. This is
> > just as (un)formal as can be, and catches exactly what you
> > want to say.
> >
> > Simple and clean. No vocabulary issues of "denotation" or whatever.
> >
> Er... isn't this bending the TM notion of an 'occurrence' somewhat?

Yes. But TM folks themselves have bent it in all of curious ways ...

> Also doesn't this just introduce an intermediate in the mapping?  I'm not sure
> that going through topic maps to get from a SKOS concept to an OWL class and
> back would be practical?

Actually that was just an idea of the kind of representation, not suggesting that it
should use a specific TM specification (XTM or TMDM). If you want to be completely
RDF-ish, replace the above *topic* by a RDF resource a:Person *with no specific type*, and
the above occurrences by matching RDF properties.

a:Person  	a:defined-in-SKOS 	eg:People
a:Person	a:defined-in-RDFS		foaf:Person

or even better, put those properties on a blank node (just got this idea)

_:node1  	a:SKOS_representation		eg:People
_:node1	a:RDFS_representation		foaf:Person

> And I think you'll find yourself going round in circles when you try to
> represent the above in RDF.  Because you could use RDF to say that 'the subject
> of topic X is a class' or 'the subject of topic Y is a concept.'

Nope. The 'subject' is neither a class, nor a concept to begin with. It's something
unformal, with no type, that happens to be represented as a SKOS concept or a RDFS class
... I think the blank node representation is really cool.

> The TM notion of a 'subject' and the RDF notion of a 'resource' are essentially
> (i.e. they are the 'things' that we make 'statements' about).  Therefore
> asserting the right sort of mapping relationship between two things depends
> alot on what sort of things they are, and not at all on the language/formalism
> (i.e. RDF, TM, whatever ...) that is being used to make the statements about them.

Agreed, but I fail to see your point. Does the above help?

> I've got this nagging feeling that if I understand RDF semantics I'd be able to
> make sense of all this.  Is there anything good on the web explaining (for a
> dunce) what a 'model theory' or an 'interpretation' is?




Bernard Vatant
Senior Consultant
Knowledge Engineering

"Making Sense of Content" :  http://www.mondeca.com
"Everything is a Subject" :  http://universimmedia.blogspot.com

Received on Tuesday, 14 June 2005 17:44:57 UTC

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