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Re: refining closure text for rdfs-isDefinedBy-semantics

From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
Date: Tue, 11 Jun 2002 16:57:51 +0100
Message-Id: <5.1.0.14.2.20020611164824.039c55c0@joy.songbird.com>
To: Eric Miller <em@w3.org>
Cc: RDF Core <w3c-rdfcore-wg@w3.org>

Eric,

Apart from the point that Aaron raised, that looks fine to me.

Bit if rdfs:isDefinedBy is also used to reference human-readable documents, 
and we want to accommodate that, then maybe the new schema classes need to 
be expanded a little; e.g.

rdfs:SchemaInRDF a rdfs:Class ;
   rdfs:subClassOf rdfs:Schema ;
   rdfs:label "An RDF schema document in RDF" ;
   rdfs:comment
    """An RDF document containing defining information about
       some RDF vocabulary (i.e. about some RDF properties and
       classes)""" .

rdfs:Schema a rdfs:Class ;
   rdfs:label "RDF vocabulary definition" ;
   rdfs:comment
    """A document, which may be machine- or human-readable,
       containing defining information about some RDF vocabulary
       (i.e. about some RDF properties and classes)""" .

Another approach might be to define rdfs:Schema as above and introduce a 
new class for RDF documents of any purpose and use membership of both such 
classes to indicate the purpose of "schema in RDF" noted above.

#g
--

At 06:17 PM 6/10/02 -0500, Eric Miller wrote:
>On Mon, 2002-06-10 at 12:28, Graham Klyne wrote:
> > At 11:01 AM 6/10/02 -0500, Eric Miller wrote:
> > >A couple of open issues come to mind...
> > >
> > >- do we formally give a name to a schema resource rather than let
> > >different communities define them (this request has surfaced from the DC
> > >community working on Registries).  As was mentioned on the telecon, this
> > >approach may be useful for clarifying the relationship between rdf
> > >Schemas and Web Ontologies (e.g. rdfs:Schema subclassof web:Ontology)
> > >
> > >my suggestion would be 'yes'
> > >
> > >- do we formalize the range rdfs:isDefinedBy to be one of these schema
> > >resources
> >
> > I'm a little uncomfortable with what this might be saying, but I'd be 
> happy
> > if we can describe the schema resource referenced by rdfs:isDefinedBy as:
> >
> > [[
> > An RDF document containing defining information about some RDF vocabulary
> > (i.e. about some RDF properties and classes).
> > ]]
>
>Yes. And I'm further suggesting that we formally write this concept down
>so that others can use in their descriptions (e.g.):
>
>so to be clear, the suggestion is to add:
>
><rdfs:Class rdf:ID="Schema">
>   <rdfs:label>RDF Schema</rdfs:label>
>   <rdfs:comment>An RDF document containing defining information about
>some RDF vocabulary (i.e. about some RDF properties and
>classes)</rdfs:comment>
></rdfs:Class>
>
>and change:
>
><rdf:Property ID="isDefinedBy">
>   <rdf:type
>resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
>   <rdfs:subPropertyOf rdf:resource="#seeAlso"/>
>   <rdfs:label xml:lang="en">isDefinedBy</rdfs:label>
>   <rdfs:label xml:lang="fr">esD&#233;finiPar</rdfs:label>
>   <rdfs:comment>Indicates a resource containing and defining the subject
>resource.</rdfs:comment>
>   <rdfs:range rdf:resource="#Resource"/>
>   <rdfs:domain rdf:resource="#Resource"/>
></rdf:Property>
>
>-- ala http://www.w3.org/2000/01/rdf-schema
>
>to...
>
><rdf:Property rdf:ID="isDefinedBy">
>   <rdfs:subPropertyOf rdf:resource="#seeAlso"/>
>   <rdfs:label xml:lang="en">isDefinedBy</rdfs:label>
>   <rdfs:label xml:lang="fr">esD&#233;finiPar</rdfs:label>
>   <rdfs:comment>Indicates a resource containing and defining the subject
>resource.</rdfs:comment>
>   <rdfs:range rdf:resource="#Schema"/>
>   <rdfs:domain rdf:resource="#Resource"/>
></rdf:Property>
>
><!-- note I'd suggest clarifying the comment -->
>
>or is this level of formalism the part you're uncomfortable with?
>
> > What I want to avoid doing here is (a) creating an idea that a schema is
> > somehow apart from the wider body of RDF data, and (b) that a schema
> > contains only statements based on the RDFS-defined vocabulary (rdfs:range,
> > rdfs:domain, etc.).
>
>I absolutely agree. I don't mean to suggest otherwise.
>
>--
>eric miller                              http://www.w3.org/people/em/
>semantic web activity lead               http://www.w3.org/2001/sw/
>w3c world wide web consortium            http://www.w3.org/

-------------------
Graham Klyne
<GK@NineByNine.org>
Received on Tuesday, 11 June 2002 13:03:16 EDT

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