[oslc-core] Comment on ResourceShape resources

[Arthur Ryman]

Dave,

This is a very old issue. rdf:predicate is not appropriate here since it 
implies that its subject is an rdf:Statement.  See [1]. That is why we 
introducing an oslc property here.

I see that Dave Steinberg picked up the same problem.

[1] http://www.w3.org/TR/rdf-schema/#ch_reificationvocab

Regards, 
___________________________________________________________________________ 

Arthur Ryman, PhD, DE


Chief Architect, Project and Portfolio Management

IBM Software, Rational

Markham, ON, Canada | Office: 905-413-3077, Cell: 416-939-5063
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From:
Dave <snoopdave at gmail.com>
To:
oslc-core <oslc-core at open-services.net>
Date:
05/26/2010 08:39 AM
Subject:
Re: [oslc-core] Comment on ResourceShape resources
Sent by:
oslc-core-bounces at open-services.net



Thanks for the excellent feedback Ian and I agree pdf:predicate seems
a much better fit here. I captured this issue on the issues page and
applied your suggested change to the Resource Shape resource
definition in appendix A.

So far we are using two notions from RDFS: the notion of a resource
definition, known as a class in the RDFS terminology, and
rdf:predicate. Perhaps I should add RDFS to the list of references at
the end of the spec.

- Dave


On Wed, May 19, 2010 at 8:02 AM, Ian Green1 <ian.green at uk.ibm.com> wrote:
> Hi all,
>
> the resource shape spec states that a Shape resource has zero-or-more
> oslc:Property's
>
>
> an oslc:Property has a (Resource, exactly-one) "rdf:type".
>
> This is a category error in the RDF model.  The rdf:type is the type of
> the instance, not the type of the RDF predicate which is modelling the
> oslc:Property.
>
> To be concrete - here is an example from the draft:
>
>
>
> <oslc:property>
>         <oslc:Property>
>             <oslc:name>modified</oslc:name>
>             <oslc:occurs>exactly-one</oslc:occurs>
>             <oslc:namespace rdf:resource="http://purl.org/dc/terms#" />
>             <rdf:type rdf:resource="http://purl.org/dc/terms#modified" 
/>
>             <oslc:valueType rdf:resource="
> http://www.w3.org/2001/XMLSchema#dateTime" />
>         </oslc:Property>
>     </oslc:property>
>
> This asserts that there is a resource, of rdf:type oslc:Property AND 
also
> of rdf:type http://purl.org/dc/terms#modified
>
> We don't mean this.   We mean that the oslc:Property is indicated by an
> RDF predicate http://purl.org/dc/terms#modified.
>
> I suggest we change this part of the spec. to use rdf:predicate rather
> than rdf:type.  So the example becomes:
>
> <oslc:property>
>         <oslc:Property>
>             <oslc:name>modified</oslc:name>
>             <oslc:occurs>exactly-one</oslc:occurs>
>             <oslc:namespace rdf:resource="http://purl.org/dc/terms#" />
>             <rdf:predicate rdf:resource="
> http://purl.org/dc/terms#modified" />
>             <oslc:valueType rdf:resource="
> http://www.w3.org/2001/XMLSchema#dateTime" />
>         </oslc:Property>
>     </oslc:property>
>
>    -ian
>
> ian.green at uk.ibm.com (Ian Green1/UK/IBM at IBMGB)
> Chief Software Architect, Requirements Definition and Management
> IBM Rational
>
>
>
>
>
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