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Fwd: Re[2]: OWL CR feedback: owl:Class 'vs' rdfs:Class causing pain. Is owl:Class really needed?

From: Jim Hendler <hendler@cs.umd.edu>
Date: Thu, 18 Sep 2003 06:21:29 -0400
Message-Id: <p05200f3ebb8f3672db23@[]>
To: webont <www-webont-wg@w3.org>

There has been a thread on public-webont-comments about owl:class vs. 
rdf:class.  Dan has asked that the general discussion could go to 
rdf-logic, but that document issues should be discussed here, and 
this was a response to that.  I bring it to the WG because I think he 
makes some important points - while we cannot change the design at 
this point, we could change the writeup (Guide/Ref) to more clearly 
discuss some of this -- in particular, I think some of his comments 
could be integrated into Guide as "OWL Full" notes or something like 
  - JH

Date: Thu, 18 Sep 2003 11:59:04 +0200
>To: Jim Hendler <hendler@cs.umd.edu>
>Cc: public-webont-comments@w3.org
>From: Benjamin Nowack <office@e-senses.de>
>Subject: Re[2]: OWL CR feedback: owl:Class 'vs' rdfs:Class causing pain. Is
>	owl:Class really needed?
>X-Spam-Status: No, hits=-26.0 required=5.0
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>in my opinion, it would fit well into the Guide and Reference.
>For people who understand the AS document the issue may be
>obvious but the non DL folks will probably start with the Guide
>and continue with the Reference. There is already a NOTE in
>chapter 3.1 of the Reference that is quite close to this stating
>that in OWL Lite and OWL DL "owl:Class" must be used for all
>class descriptions. The NOTE below explains that owl:Class is
>a subclass of rdfs:Class. Maybe you could just add if this
>means that vocabularies defined in RDF Schema can not be used
>(imported, linked) in OWL (Lite, DL) ontologies, neither
>their terms nor their classes (I still hope that I'm wrong..).
>In section 7.1 a Dublin Core term is reused as AnnotationProperty
><owl:AnnotationProperty rdf:about="&dc;creator" />
>If this is not allowed for rdf schema classes or in no context
>other than AnnotationProperty it could be helpful to explicitly
>say that. I saw several ontologies that use something like e.g.
><owl:Class rdf:about="&foaf;Person" />
>or even
><owl:Class rdf:ID="Person">
>    <owl:equivalentClass rdf:resource="&foaf;Person" />
>trying to "make" the rdfs:Class of the FOAF spec an owl:Class.
>Same for properties:
><owl:DatatypeProperty rdf:about="&dc;creator" />
>or (even more confusing)
><owl:ObjectProperty rdf:about="&foaf;mbox">
>    <rdfs:range rdf:resource="&rdfs;Resource" />
>(in order to be able to make use of
>   owl:InverseFunctionalProperty)
>Whether this was allowed/not allowed could be mentioned
>somewhere in the Guide or the Reference. Maybe in section
>3.2.2 (owl:equivalentClass) as people will probably look
>here when they try to map different ontologies/vocabularies.
>(I personally don't need a more detailed explanation of why
>rdfs:Class and owl:Class aren't equivalent in OWL Lite and
>OWL DL. Just some notes on what this means for people trying
>to build OWL tools or write OWL ontologies.)
>benjamin nowack
>am exerzierplatz 1
>de-97072 wuerzburg
>Jim Hendler (hendler@cs.umd.edu) schrieb am 18.09.2003:
>>   you asked a good question for which, as you see from Pat's message,
>>the answer is more complex than you might think.  From the point of
>>view of our documents/CR let me ask you this - which document would
>>you expect to look in to see a "human readable" answer?  Seems to me
>>my WG should add a paragraph or two that answers in an "informal" way
>>to one of our informative documents
>>   -JH
>>Professor James Hendler				  hendler@cs.umd.edu
>>Director, Semantic Web and Agent Technologies	  301-405-2696
>>Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
>>Univ of Maryland, College Park, MD 20742	  *** 240-277-3388 (Cell)
>>http://www.cs.umd.edu/users/hendler      *** NOTE CHANGED CELL NUMBER ***
Professor James Hendler				  hendler@cs.umd.edu
Director, Semantic Web and Agent Technologies	  301-405-2696
Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
Univ of Maryland, College Park, MD 20742	  *** 240-277-3388 (Cell)
http://www.cs.umd.edu/users/hendler      *** NOTE CHANGED CELL NUMBER ***
Received on Thursday, 18 September 2003 06:21:40 UTC

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