Re: SKOS queries

I strongly believe that the semantics of all relations in SKOS are 
musb be *consistent*--if this isn't the case, then users who want to 
use SKOS terminologies/ontologies for reasoning will not be able to 
do so. This is similar to the importance of every class in SKOS 
having a single definition. If the semantics of relations and 
meanings of classes are context-dependent, then those context 
dependencies need to be incorporated in SKOS.

Daniel

At 09:19 AM 9/27/2007, Sean Bechhofer wrote:


>On 27 Sep 2007, at 09:50, Quentin Reul wrote:
>
>>
>>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.
>
>I think there is some confusion here about "transitivity". The
>skos:broader and skos:narrower relations are intended to be / 
>inverses/. If the user defines a thesaurus that contains only
>skos:broader relationships, then an application/implementation that
>respects the SKOS semantics should be able to tell me about
>skos:narrower relationships. So from
>
>a skos:broader b
>
>I should be able to get that
>
>b skos:narrower a
>
>If skos:broader is /transitive/, then from
>
>a skos:broader b
>b skos:broader c
>
>then I can infer
>
>a skos:broader c
>
>It is not clear that broader/narrower should necessarily be
>transitive relations. As Antoine said, a decision regarding
>transitivity of the relations depends very much on requirements and
>use cases.
>
>         Sean
>
>--
>Sean Bechhofer
>School of Computer Science
>University of Manchester
>sean.bechhofer@manchester.ac.uk
>http://www.cs.manchester.ac.uk/people/bechhofer
>
>
>