W3C home > Mailing lists > Public > public-webont-comments@w3.org > September 2003

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 06:25:03 -0400
Message-Id: <p05200f3fbb8f37be28e0@[]>
To: Benjamin Nowack <office@e-senses.de>
Cc: public-webont-comments@w3.org

Benjamin, thanks for your comments - I have taken the liberty of 
forwarding this to the WG (see the W3C mailing list archive for 
www-webont-wg@w3.org) so that we can figure out what document changes 
to make to better explain this.  We really appreciate your comments
  -Jim H.
  WG CoChair

At 11:59 AM +0200 9/18/03, Benjamin Nowack wrote:
>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 06:25:14 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:09:29 UTC