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RE: ISSUE-130 draft response

From: Houghton,Andrew <houghtoa@oclc.org>
Date: Wed, 1 Oct 2008 12:21:40 -0400
Message-ID: <6548F17059905B48B2A6F28CE3692BAA015A1E46@OAEXCH4SERVER.oa.oclc.org>
To: "Alistair Miles" <alistair.miles@zoo.ox.ac.uk>
Cc: "Antoine Isaac" <aisaac@few.vu.nl>, <public-swd-wg@w3.org>

> From: Alistair Miles [mailto:alistair.miles@zoo.ox.ac.uk]
> Sent: Wednesday, October 01, 2008 12:11 PM
> To: Houghton,Andrew
> Cc: Antoine Isaac; public-swd-wg@w3.org
> Subject: Re: ISSUE-130 draft response
> 
> > Actually I wasn't suggesting a new class for TopConcept, but a
> mechanism for specifying that a skos:Concept is a top concept.
> Something like:
> >
> > <skos:Concept rdf:about="concept URI">
> >   <skos:isTopConcept rdf:resource="in-scheme URI" />
> > </skos:Concept>
> >
> > skos:isTopConcept could be an inverse of skos:hasTopConcept in the
> skos:ConceptScheme.  This way you could specify a top concept where it
> makes the most sense.
> 
> Yes, this is what skos:topConceptOf is intended for, e.g.
> 
> <skos:Concept rdf:about="MyConcept">
>   <skos:topConceptOf rdf:resource="MyScheme" />
> </skos:Concept>
> 
> Does this work for you?

Yes, I must have read the SKOS reference incorrectly for skos:topConceptOf.  After re-reading it still wasn't clear, but I found this snipit in another section that made it clearer:

<A> rdf:type skos:Concept ;
  skos:prefLabel "love"@en ;
  skos:altLabel "adoration"@en ;
  skos:broader <B> ;
  skos:inScheme <S> .

<B> rdf:type skos:Concept ;
  skos:prefLabel "emotion"@en ;
  skos:altLabel "feeling"@en ;
  skos:topConceptOf <S> .

<S> rdf:type skos:ConceptScheme ;
  dc:title "My First Thesaurus" ;
  skos:hasTopConcept <B> .

So I definitely support the inclusion of skos:topConceptOf, maybe a suggestion on wording to skos:isTopConceptOf, but either one works for me.

> From: Alistair Miles [mailto:alistair.miles@zoo.ox.ac.uk]
> Sent: Wednesday, October 01, 2008 12:07 PM
>
> I think there are two points to consider here.
> 
> First the query may be easy to build, but may not be fast to execute
> for large concept schemes. It is one of those OPTIONAL .. FILTER
> !bound.. queries, which can be slow for large datasets in my
> experience. Hence the skos:hasTopConcept/skos:topConceptOf provides an
> efficient alternative to searching the graph.

And for applications not built on the RDF tool chain, they provide an indication of intent without inference.

> Second, a concept scheme might have "orphans" as you
> suggest.. concepts which don't have any broader concepts, but where
> the intention is not to consider it as one of the top level concepts
> in a tree browser. This could be the case e.g. were a scheme is under
> development, and many new concepts are being added and as yet not
> given any parent.
> 
> These two points for me have provided the rationale for
> skos:hasTopConcept/skos:topConceptOf. On both of these I defer to
> those with more implementation experience.

I agree with Alistair on these two points.


Sorry for the confusion with skos:hasTopConcept, Andy.
Received on Wednesday, 1 October 2008 16:22:25 GMT

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