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Re: SEM: Light review of semantics document

From: Jeff Heflin <heflin@cse.lehigh.edu>
Date: Thu, 07 Nov 2002 11:15:20 -0500
Message-ID: <3DCA9198.D7F8DCB4@cse.lehigh.edu>
To: pat hayes <phayes@ai.uwf.edu>
CC: www-webont-wg@w3.org

pat hayes wrote:
> 
> >Here's some initial comments on the Semantics document dated Nov. 3:
> >
> >1) Sect. 2.2. The syntax needs the ability to represent documents that
> >consist soley of facts (that is, something other than ontologies).
> 
> ? Can you explain what you mean by "other than ontologies" ?Do you
> mean, not in OWL?
> 

Part of this depends on what you consider OWL. From your response, I
assume that you think of OWL as just a language for defining ontologies,
and that you must use it with RDF in order to describe data (e.g., a
product catalog, a univeristy's course offerings, etc.). I tend to think
of OWL as an extension to RDF, so this data is still part of OWL, it
just has the standard RDF syntax. 

In any case, our model theory must talk about data to the same extent
that it talks about ontologies. We must be able to formulate every
possible OWL/RDF document in the OWL abstract syntax. Since RDF does not
have anything that corresponds to this abstract syntax, we must create
syntax for representing these content/data document, so that the
abstract syntax model theory can assign meaning to them.

Jeff

p.s. We need a good word for these documents that consist only of
instances. I've used the terms "data document" and "content document" in
the past, but am not quite satisfied with that terminology. However, one
thing is sure, there will be many more of these than there will be
ontologies. If the world bought into the Semantic Web, there may be
thousands of ontologies, but there will be billions of data documents.
After all, in the ideal Semantic Web, every web page would have some
associated instance data with it.
Received on Thursday, 7 November 2002 11:15:22 GMT

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