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Re: refining closure text for rdfs-isDefinedBy-semantics

From: Frank Manola <fmanola@mitre.org>
Date: Wed, 12 Jun 2002 16:03:15 -0400
Message-ID: <3D07A903.DA6370B1@mitre.org>
To: patrick hayes <phayes@ai.uwf.edu>
CC: Patrick Stickler <patrick.stickler@nokia.com>, w3c-rdfcore-wg@w3.org

Pat--

How about some suggestions for what we ought to mean by "define"? 
Especially since it's hard to avoid the use of "define" when trying to
describe "isDefinedBy".

--Frank

patrick hayes wrote:
> 
> >On 2002-06-11 10:29, "ext Patrick Stickler" <patrick.stickler@nokia.com>
> >wrote:
> >
> >>
> >>  On 2002-06-10 19:01, "ext Eric Miller" <em@w3.org> wrote:
> >>
> >>>  Now that i'm back online, I see Patrick's suggestion...
> >>>
> >>>  On Fri, 2002-06-07 at 11:15, Patrick Stickler wrote:
> >>>
> >>>>  My specific recommendations are:
> >>>>
> >>>>  1. Leave the definition of rdfs:isDefinedBy as is, though removing
> >>>>  the incorrect language about namespaces, allowing any instance
> >>>>  of rdf:Resource and multiple statements.
> >>>>
> >>>>  2. Qualify objects of rdfs:isDefinedBy by class, in the case of
> >>>>  RDF/XML instances, by the proposed rdfs:Schema class. This permits
> >>>>  those who want/need to, to be explicit about the nature of the
> >>>>  defining resource.
> >>>>
> >>>>  3. Clearly state that there is no functional relationship between
> >>>>  the URI of a term and the namespace URI used in its RDF/XML
> >>>>  serialization -- that the RDF model is based on URIs, not
> >>>>  qnames, and as such, namespaces have no significance whatsoever.
> >>>
> >>>  yep, i believe we're saying similar things.
> >>>
> >>>  Patrick, have you taken a crack at this rewording?
> >>
> >>  Not yet, but I would be happy to do so prior to Friday's telecon.
> >
> >Here goes:
> >
> ><rdfs:Property rdf:about="&rdfs;isDefinedBy">
> >    <rdfs:subPropertyOf rdf:resource="&rdfs;seeAlso"/>
> >    <rdfs:domain rdf:resource="&rdf;Resource"/>
> >    <rdfs:range rdf:resource="&rdf;Resource"/>
> >    <rdfs:comment>
> >        This property indicates a resource which fully or partially
> >        defines the subject resource.
> 
> I insist that we do not put this into a spec unless we also say
> something about what we mean by 'define'. That word has no formal
> meaning in an assertional language like RDF and RDFS, and it is a
> very dangerous word to use casually. (For example, the difference
> between a simple contradiction and a very nasty paradox turns on the
> distinction between 'assert' and 'define', and this has been a
> central issue in the Webont layering problems.). I would prefer to
> avoid the use of the 'define' word altogether if we possibly can,
> particularly when used with 'resource'.
> 
> >The subject of this property
> >        can be any instance of rdfs:Resource and may have as its
> >        value any rdfs:Resource.
> 
> Why bother saying that? *Everything* is an instance of rdfs:Resource,
> so this isn't saying anything.
> 
> >The most common anticipated usage
> >        is to relate a vocabulary term to an instance of rdfs:Schema
> >        containing defining information about that term.
> >    </rdfs:comment>
> ></rdfs:Property>
> >
> ><rdfs:Class rdf:about="&rdfs;Schema">
> >    <rdfs:comment>
> >       An RDF/XML instance.
> >    </rdfs:comment>
> ></rdf:Class>
> >
> >(and no, I don't consider the definition of rdfs:Schema to be
> >  too narrow; folks can still point to N3 instances if they like,
> >  but an rdfs:Schema is a standard serialization of RDF statements)
> >
> >Cheers,
> >
> >Patrick
> >


-- 
Frank Manola                   The MITRE Corporation
202 Burlington Road, MS A345   Bedford, MA 01730-1420
mailto:fmanola@mitre.org       voice: 781-271-8147   FAX: 781-271-8752
Received on Wednesday, 12 June 2002 16:05:30 EDT

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