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Re: SKOS queries

From: Quentin Reul <qreul@csd.abdn.ac.uk>
Date: Thu, 27 Sep 2007 09:50:12 +0100
Message-ID: <46FB6EC4.70405@csd.abdn.ac.uk>
To: Antoine Isaac <aisaac@few.vu.nl>
CC: SWD WG <public-swd-wg@w3.org>

Hi Antoine,

The goal of SKOS is to share knowledge organisation, such as thesauri 
over the web. Imagine that a user defines a thesaurus containing only 
skos:broader relations between skos:Concept. If skos:broader and 
skos:narrower are not transitive, a user x who wants to use this 
thesaurus to find all narrower concepts of a concept will have to add 
the relation to every concept in the thesaurus. Hence, transitivity 
between these relations enable a better sharing among user.

Looking at [1], I realised that my question is already covered. I have 
reviewed the different solutions proposed. I believe that solution 4 
(mixing 1 and 2), despite is cons, would be most appropriate. SKOS 
relations such as skos:definition and skos:altLabel offer more 
information about the concept described whereas skos:broader and 
skos:narrower describes relations between terms (in my view anyway). 
Furthermore, FOAF and Dublin Core are sometimes used in OWL ontologies 
to add information about concept or the ontology itself.

Lastly, I was wondering if the group was planning on addressing the 
question of ambiguity between terms.



[1] http://www.w3.org/2006/07/SWD/wiki/SkosDesign/ConceptSemantics

Antoine Isaac wrote:
> Hi Quentin,
>> I understood that skos:narrower and skos:broader are inverses. And I 
>> guess my question is actually going to be covered as part of the f2f 
>> in Amsterdam [1] in a few weeks time. My personal opinion is that 
>> these should be transitive in a similar manner to rdfs:subClass in OWL 
>> especially if users want to be able to get information through inference.
> Do you have a specific application which requires this? For the moment 
> my personal opinion is rather not enthousiastic about transitivity, and 
> it's grounded in some practical concerns. I guess other workgroup member 
> will come with strong arguments for transitivity, but the more practical 
> cases we can discuss, the better...
>> Another question that comes to mind is whether SKOS is intended to be 
>> used as stand-alone or within an ontology. As part of the project I 
>> work on, we have used SKOS properties such as skos:definition to 
>> define concept label in OWL ontologies. But I also can see some 
>> applications where SKOS can be used to represent thesaurus on its own.
> Your sentence is unclear: do my scribblings in [1]  cover this problem?
> Cheers,
> Antoine
> [1] http://www.w3.org/2006/07/SWD/wiki/SkosDesign/ConceptSemantics
>> Sean Bechhofer wrote:
>>> On 24 Sep 2007, at 11:41, Quentin Reul wrote:
>>>> Hi,
>>>> I have looked at different aspects of SKOS and I have got a few 
>>>> questions as a result:
>>>> First of all, I was wondering if there was any reasoner available to 
>>>> create a thesaurus tree and find out all the different terms that 
>>>> are "broader/narrower" for a given term.
>>>> My understanding is that the "broader/narrower" relationship is 
>>>> transitive, i.e. if the user adds a term has being broader, this 
>>>> term would have the previous term as narrower without having to add 
>>>> the statement to the second term.
>>> Broader/narrower are intended to be *inverses*, which I think is what 
>>> you mean here.
>>> The transitivity of broader/narrower is one of the topics that's up 
>>> for discussion at the F2F. See "Semantic Relation Properties" in [1].
>>> Cheers,
>>>     Sean
>>> [1] http://www.w3.org/2006/07/SWD/wiki/AmsterdamAgenda
>>> -- 
>>> Sean Bechhofer
>>> School of Computer Science
>>> University of Manchester
>>> sean.bechhofer@manchester.ac.uk
>>> http://www.cs.manchester.ac.uk/people/bechhofer
>> ------------------------------------------------------------------------
>> Quentin H. Reul
>> Computing Science
>> University of Aberdeen
>> +44 (0)1224 27 *4485*
>> qreul@csd.abdn.ac.uk
>> http://www.csd.abdn.ac.uk/~qreul


Quentin H. Reul
Computing Science
University of Aberdeen

+44 (0)1224 27 *4485*
Received on Thursday, 27 September 2007 08:50:37 UTC

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