Re: SKOS Consistency

Hi Quentin,

On Tue, Jul 06, 2010 at 10:47:09AM +0200, Quentin Reul wrote:
> 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.

Just adding a general comment to Antoine's nice reply, the open world
assumption which is part of the RDF and OWL semantics means that an
absence of some data cannot give rise to inconsistency. 

I.e., you can only become inconsistent by saying things (and
contradicting yourself), not by forgetting to say something.

Checking for "missing" data is, however, very useful in some
circumstances. E.g., if you have a file which you know is supposed to
contain all the data for a complete thesaurus, you might then check to
see if any concepts are missing a prefLabel in some language. In this
case, your check effectively assumes a closed world. This is a
perfectly reasonable thing to do, but this type of checking is beyond
the scope of the SKOS reference. 

I.e., the SKOS reference *will* tell you if your data is inconsistent
(in an open world). It *will not* tell you if your data is missing
anything, because how you define missingness is up to you, and you
will want to vary your definition depending on what you're trying to
achieve.

Hth,

Alistair

> 
> Cheers,
> 
> Quentin
> 
> [1] http://www.w3.org/TR/skos-reference
> 
> -- 
> Quentin Reul
> 
> Semantic Technology Consultant
> TenForce BVBA
> Haachtsesteenweg 378
> 1910 Kampenhout
> Belgium

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

Received on Thursday, 8 July 2010 10:53:07 UTC