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Re: Review of Reference

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 02 Jan 2003 21:59:26 -0500 (EST)
Message-Id: <20030102.215926.108004927.pfps@research.bell-labs.com>
To: hendler@cs.umd.edu
Cc: www-webont-wg@w3.org

From: Jim Hendler <hendler@cs.umd.edu>
Subject: Re: Review of Reference
Date: Thu, 2 Jan 2003 18:58:37 -0500

[...]

> >- Property elements, last para. "A property is a binary relation that
> >may or may not be defined in the ontology." Did the WG ever discuss
> >whether or not it was legal to reference a class or property that wasn't
> >defined in the ontology? I certainly would not support this. It makes it
> >even easier for errors to creep into ontologies.
> 
> I must be missing something, we had long discussion about reference 
> to things outside current ontology during the imports debate in 
> particular.  I can certainly say in document A that something is a 
> B:foo (foo a class) where B is a different document and no imports is 
> specified.  Do you mean something different by "not defined in the 
> ontology"?

In OWL/Lite and OWL/DL, just about everything needs to be placed in some
category, so you need to at least know whether a property is a datatype
property or an object property.  In OWL/Full there is no such need.

The issue of whether a URI reference comes from a different namespace is an
entirely different matter.

[...]

> >Here are some additional comemnts on
> >http://www.daml.org/2002/06/webont/owl
> >
> >- We should import the Dublin Core schema. i.e. add:
> >   <imports rdf:resource="http://purl.org/dc/elements/1.1/">
> >to the ontology header.
> 
> I endorse this idea - consistent with previous decisions re: Dublin 
> Core, and makes it easier to use DC in OWL.

I oppose this idea.   Users who want to use DC can import it themselves,
and with very little effort.  Users who do not want to use DC shouldn't get
it in their ontologies.

peter
Received on Thursday, 2 January 2003 21:59:36 GMT

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