Re: SKOS Consistency

Dear Juan Antonio,

On Thu, Jul 08, 2010 at 06:58:50PM +0200, Juan Antonio Pastor Sánchez wrote:
> Hello Quentin,
> 
> This issue is addressed in part when I raised the possibility of
> dynamic inference skos: hasTopConcept here:
> <http://old.nabble.com/Dinamic-hasTopConcept-property-to26628730.html#a26628730>

I am assuming that, given a graph like...

<A> skos:broader <B> ; skos:inScheme <S> .
<B> skos:inScheme <S> .

...you would like to be able to infer...

<S> skos:hasTopConcept <B> .

...?

If that is what you want, then note that this inference is *not* supported
by the SKOS data model. The reason for this is ... you guessed it ... the
open world assumption. I.e., in general, you cannot assume that you are in
possession of all the data ... there might always be more data out there. So,
the SKOS data model does not support any inference from the absence of data
(in this case, from the absence of a skos:broader assertion).

You are, of course, free to make whatever non-standard inferences you like,
using whatever means, and to publish your inferences back out to the web,
although it's best to avoid publishing data that is inconsistent with respect
to the SKOS data model.

Hth

Alistair

> 
> I am currently developing a thesaurus management software based on
> SKOS and have come to the conclusion that the property must be
> explicitly declared. My opinion is based on the subsequent operation
> of schemes of concepts through Endpoints> <RDF using SPARQL.
> 
> In this sense I think the management application must provide a
> maintenance operation that allows the inference of skos: hasTopConcept
> to allow more flexible management of a concept scheme.
> 
> Regards
> 
> 
> 2010/7/6 Quentin Reul <quentin.reul@tenforce.com>:
> > Hi all,
> > I was looking at the SKOS reference [1] and I was unable to determine
> > whether a SKOS model would be consistent if no skos:hasTopConcept property
> > was defined within a concept scheme.
> > Cheers,
> > Quentin
> > [1] http://www.w3.org/TR/skos-reference
> >
> > --
> > Quentin Reul
> >
> > Semantic Technology Consultant
> > TenForce BVBA
> > Haachtsesteenweg 378
> > 1910 Kampenhout
> > Belgium
> >
> 
> 
> 
> -- 
> Ph.D. Juan Antonio Pastor Sánchez
> Dep. of Information and Documentation
> Faculty of Communication and Documentation
> University of Murcia
> phone: +34 868 88 8780
> http://webs.um.es/pastor
> pastor@um.es
> 

-- 
Alistair Miles
Centre for Genomics and Global Health <http://cggh.org>
The Wellcome Trust Centre for Human Genetics
Roosevelt Drive
Oxford
OX3 7BN
United Kingdom
Web: http://purl.org/net/aliman
Email: alimanfoo@gmail.com
Tel: +44 (0)1865 287669

Received on Monday, 12 July 2010 17:42:07 UTC