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Re: SKOS Consistency

From: Alistair Miles <alimanfoo@googlemail.com>
Date: Mon, 12 Jul 2010 18:49:50 +0100
To: Antoine Isaac <aisaac@few.vu.nl>
Cc: Quentin Reul <quentin.reul@tenforce.com>, public-esw-thes@w3.org
Message-ID: <20100712174950.GA10247@aliman-desktop>
Hi Quentin

On Thu, Jul 08, 2010 at 03:01:22PM +0200, Antoine Isaac wrote:
> Quentin,
> 
> 
> >Antoine/Alistair,
> >
> >Thanks for your answers.
> >
> >I have one more question wrt the integrity of SKOS dataset. The SKOS
> >Reference states that skos:prefLabel, skos:altLabel and skos:hiddenLabel
> >are all disjoint. This leads inconsistencies when skos:prefLabel and
> >skos:altLabel and/or skos:hiddenLabel have the same value for a given
> >language. The reference also states that no concept can have 2
> >skos:prefLabel for the same language.
> >
> >Suppose now that I have two SKOS concepts as follows:
> >
> ><A>   skos:prefLabel "stringA"@en;
> >           skosxl:altLabel<C>  .
> >
> ><B>  skos:prefLabel "stringB"@en;
> >          skosxl:altLabel<C>  .
> >
> ><C>  rdf:type skosxl:Label ;
> >         skosxl:literalForm "stringC"@en .
> >
> >Would this be consistent?
> 
> 
> Yes. According to the SKOS-XL semantics this leads to both A and B having "stringC" as skos:altLabel. Which is allowed.

For contrast, the following graph...

<A> skos:prefLabel "foo"@en ; skosxl:altLabel <L> .
<L> skosxl:literalForm "foo"@en .

...is not consistent, because of [S56] and [S13]. I.e., you end up with a
clash between preferred and alternative labels.

Another example, the graph... 

<A> skos:prefLabel "foo"@en ; skosxl:prefLabel <L> .
<L> skosxl:literalForm "bar"@en .

...is not consistent, because of [S55] and [S14]. I.e., you end up with two
different preferred labels in english.

Hth

Alistair

[S13] http://www.w3.org/TR/skos-reference/#S13
[S14] http://www.w3.org/TR/skos-reference/#S14
[S55] http://www.w3.org/TR/skos-reference/#S55
[S56] http://www.w3.org/TR/skos-reference/#S56

> 
> Cheers,
> 
> Antoine
> 
> 
> >
> >Kind regards,
> >
> >Quentin
> >
> >-----Original Message-----
> >From: Alistair Miles [mailto:alimanfoo@googlemail.com]
> >Sent: donderdag 8 juli 2010 12:53
> >To: Quentin Reul
> >Cc: public-esw-thes@w3.org
> >Subject: 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 Roosevelt Drive Oxford
> >OX3 7BN
> >United Kingdom
> >Web: http://purl.org/net/aliman
> >Email: alimanfoo@gmail.com
> >Tel: +44 (0)1865 287669
> >
> >
> 
> 

-- 
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 17:50:27 UTC

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