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Re: What is an OWL document? was: Re: SEM: Light review of semantics document

From: Dan Brickley <danbri@w3.org>
Date: Wed, 20 Nov 2002 12:24:17 -0500 (EST)
To: pat hayes <phayes@ai.uwf.edu>
cc: Jonathan Borden <jonathan@openhealth.org>, <www-webont-wg@w3.org>
Message-ID: <Pine.LNX.4.30.0211201222220.14650-100000@tux.w3.org>

On Wed, 20 Nov 2002, pat hayes wrote:

> >pat hayes wrote:
> >
> >>  >
> >>  >Chris/Pat - I think you guys misunderstood me - I believe that all
> >>  >of these things are OWL documents, but I'm concerned with a small
> >>  >matter of usage.  The way I see it, there are documents which are
> >>  >clearly owl ontologies because they define terms and properties and
> >>  >the like. There are also owl documents that only use those terms
> >>
> >>  There are also RDF and RDFS documents that use those terms. So? I
> >>  thought y'all *wanted* things to work out that way, that is supposed
> >>  to be part of the layercake, right? So that people can use these
> >>  languages together all nice and smoothly. That's why we went to all
> >>  this trouble in the model theory.... Do you have a problem with this,
> >>  now??
> >>
> >>  >and, in fact, there is no reason that there will be any trace of any
> >>  >OWL vocabulary in those documents.
> >>
> >>  Well then they won't be OWL documents. They will be be, say, RDF
> >>  documents that use a vocabulary defined (yech, I hate that word) in
> >>  another document that uses OWL.
> >>
> >
> >I'd like to suggest that (assuming document's which have legal RDF/XML
> >syntax);
> >
> >Documents served with a media type: application/rdf+xml
> >
> >1) are RDF documents
> >2) might be OWL documents
> >
> >Documents served with a media type: application/owl+xml
> >
> >1) are OWL documents
> >2) are RDF documents
> >
> >That is to say: an OWL document is an RDF document which is interpreted
> >according to the OWL semantics.
> Well, OK, but look: suppose I have a doc which contains nothing but
> RDF but the RDF uses terms that are defined in an OWL doc somewhere,

defined vs described? Does OWL have a more explicit notion of 'define'
that RDF?

The term might be in a 'pure' RDF Schema namespace, but which itself
has subclasses and subproperties from namespaces which draw upon OWL
machinery. There are lots of highly plausible corner cases light this.

> and I want to know what media type I should say it has. Seems to me
> that with your scheme, it doesn't matter which I use. So why do we
> have the distinction? Whereas if we just say, xml means it  looks
> like XML, rdf means it looks like RDF, and owl means it looks like
> OWL, then we are giving some useful syntactic information to a parser
> which might need to know it.
Received on Wednesday, 20 November 2002 12:24:19 UTC

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