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Re: ISSUE-129 draft response

From: Alistair Miles <alistair.miles@zoo.ox.ac.uk>
Date: Tue, 7 Oct 2008 16:23:35 +0100
To: Sean Bechhofer <sean.bechhofer@manchester.ac.uk>
Cc: SWD Working SWD <public-swd-wg@w3.org>
Message-ID: <20081007152335.GB9069@skiathos>

Yes, I agree. While it is tempting to allow this sort of punning for
convenience in some situations, I would be concerned that this would
promote too much heterogeneity in the use of SKOS, making it difficult
to write generic SKOS software to cope with all possibilities.

Cheers,

Alistair.

On Mon, Oct 06, 2008 at 01:23:40PM +0100, Sean Bechhofer wrote:
>
>
> Hi all,
>
> Here's a draft response to Lourens on [ISSUE-129], let me know what you
> think. Note *this is just a draft, not the actual response* -- I'll
> wait for feedback from the WG before replying formally to
> Lourens. (Lourens if you're lurking on this list feel free to post your
> thoughts at any time.)
>
> 	Sean
>
>
> Dear Lourens
>
> Thank you for your comments [1]:
>
> """
> A comment on
> "S9 skos:ConceptScheme is disjoint with skos:Concept "
>
> I have considered modelling complex thesauri containing sub thesauri
> describing different aspects of objects (persons,subjects,..) as
> a general concept scheme having sub thesauri as top concepts.
> (often the pre-skos version is organized as a tree with top level
> children nodes that are the aspects themselves).
>
> ct:complex_thesaurus rdf:type skos:ConceptScheme
> ct:complex_thesaurus skos:hasTopConcept ct:subjects
> ct:complex_thesaurus skos:hasTopConcept ct:persons
> ct:complex_thesaurus skos:hasTopConcept ...
>
> then,
>
> ct:subjects rdf:type skos:Concept,
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> but I would also like
> ct:subjects" rdf:type skos:ConceptScheme
>
> I would put all ct:complex_thesaurus concepts skos:inScheme  
> ct:complex_thesaurus
>
> ct:subject1 rdf:type skos:Concept
> ct:subject1 skos:broader ct:subjects
> ct:subject1 skos:inScheme ct:subjects
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> ct:subject1 skos:inScheme ct:complex_thesaurus
>
> Then, ct:complex_thesaurus would be a proper conceptscheme with tree
> but its subtree ct:subjects would also be a proper conceptscheme.
>
> Why? Because I would dislike having to define two distinct URIs for
> the subject that is a topconcept of ct:complex_thesaurus and
> the subject that is a Conceptscheme that defines all subjects concepts 
> that are
> descendants of the ct:subjects concept. I would then need to define some 
> ad hoc
> property linking both subject uris.
> """
>
> Requires discussion.
>
> ------------------------------------------------
>
> If I understand your use case correctly, you would like to define a  
> composite thesaurus where the composition of the thesaurus is  
> essentially represented using the hasTopConcept relation between the  
> "super"-thesaurus and its constituent parts (treating each constituent 
> thesaurus as a subject for this purpose). Speaking personally, I would be 
> a little concerned at the use of the SKOS relations for this purpose as 
> you are in some ways overloading the interpretation of the relationships. 
> It may be better to approach this using existing mechanisms for 
> modularity (such as owl:imports).
>
> As you discuss, in the SKOS data model, a concept scheme is viewed as an 
> aggregation of a number of Concepts and we have chosen to make Concept 
> and ConceptScheme disjoint. This does then require the introduction of 
> additional URLs to identify the scheme and the concepts but we believe 
> that maintaining a separation between the two notions aids clarity.
>
> I hope this helps and that you are able to live with the current  
> situation.
>
> Cheers,
>
> 	Sean Bechhofer
> 	Alistair Miles
>
> [ISSUE-129] http://www.w3.org/2006/07/SWD/track/issues/129
> [1] http://lists.w3.org/Archives/Public/public-swd-wg/2008Sep/0014.html
>
>
> --
> Sean Bechhofer
> School of Computer Science
> University of Manchester
> sean.bechhofer@manchester.ac.uk
> http://www.cs.manchester.ac.uk/people/bechhofer
>
>
>
>

-- 
Alistair Miles
Senior Computing Officer
Image Bioinformatics Research Group
Department of Zoology
The Tinbergen Building
University of Oxford
South Parks Road
Oxford
OX1 3PS
United Kingdom
Web: http://purl.org/net/aliman
Email: alistair.miles@zoo.ox.ac.uk
Tel: +44 (0)1865 281993
Received on Tuesday, 7 October 2008 15:24:13 GMT

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