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Re: Media types for the Semantic Web

From: Mark Baker <distobj@acm.org>
Date: Wed, 31 Mar 2004 15:06:51 -0500
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: public-sw-meaning@w3.org
Message-ID: <20040331200651.GU11976@markbaker.ca>

On Wed, Mar 31, 2004 at 01:40:52PM -0500, Peter F. Patel-Schneider wrote:
> > Deploying new media types is currently expensive; if you have the option
> > between communicating some information using application/rdf+xml,
> > instead of with application/prs.pps.foobar+rdf+xml, you should, in
> > general, opt for the former (unless you know the recipient can handle
> > it, of course, but obtaining that information doesn't scale).
> 
> Well, sure, if you have the option.  However, what if you don't?  
> 
> The example that I used before
> 
>  	ex:foo owl:sameAs ex:bar .	
> 
> has a different meaning when treated as an OWL ontology than when treated
> as an RDF ontology.   Sending it as application/rdf+xml means, to me, that
> you are sending as a triple with no special meaning attached to owl:sameAs,

Yes, it means that to me too.

> whereas if it is sent as OWL (by whatever means you like) then the triple
> means that ex:foo and ex:bar have the same denotation.

Yes, exactly.

So by "what if you don't", do you mean that there's no equivalent
licensed-as-RDF graph which can communicate that same information?

> Actually I would much prefer to send it (or a close variation of it) as
> the OWL ontology
> 
> 	Ontology(
> 		Class(ex:foo complete ex:bar)
> 	)
> 
> which, to me, is much preferable in every way.

I'll have to look that up.

> > I can forsee the day when we have dereferenceable media types so that an
> > agent can, upon seeing an unrecognized one, dereference it to learn that
> > it's just a specialization of some type it already knows (e.g. in terms
> > of application/rdf+xml) with its own axiomatic triples.  But until
> > that's common practice, I think it's best to avoid minting new ones.
> 
> Well, that assumes that you have some powerful logic backing up the
> communication, which is certainly not the case with RDF.   Even if you do,
> I would not advocate this approach, instead retaining an approach where the
> formalism in which the communication is to be interpreted is sent by
> reference and is not specified as a theory in this powerful logic.

Agreed.

Mark.
-- 
Mark Baker.   Ottawa, Ontario, CANADA.        http://www.markbaker.ca
Received on Wednesday, 31 March 2004 14:59:58 GMT

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