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Re: Modeling change in and between schemes using SKOS - the problem of persistent URIs

From: Jakob Voss <jakob.voss@gbv.de>
Date: Tue, 29 Aug 2006 11:27:08 +0200
Message-ID: <44F4086C.80002@gbv.de>
To: public-esw-thes@w3.org

Dear Joseph Tennis,

I can only give some naive comments - maybe they help.

> Hello.  I, along with Stuart Sutton, have started to model changes in
> schemes using SKOS.  We want to keep track of changes within and between
> versions of schemes.  However, we've run into a problem.  The problem is:
> 
> 1. SKOS postulates a concept exists independent of a scheme

That's also general in the Semantic Web as far as I understand.

> 2. This means that a concept can exist in many schemes (further
> demonstrated by SKOS's inScheme)
> 3. However, each scheme delimits the meaning of a concept by
> its relationships with other concepts in the scheme.

This is a rather philosophical question. The meaning of a concept is its
usage (subjectivism) or its inherent meaning (objectivism) but it does
not depend on which relations are known in which scheme. If a concept is
in two schemes than its either the same (same meaning) or not (different
concept).

> 4. Change notes, as properties of concepts, are not linked to the scheme
> in which the change applies.

Because they are independent from Schemes.

> 5. We are left to ask: how do we model scheme specific changes to
> concepts without signaling a new URI?

You have to judge if the change is relevant enough to introduce a new
concept are just use the same concept.

> You can see an illustration of the problem at:
> http://www.ischool.washington.edu/sasutton/skos/Concept_History_New.html
> 
> You can also see how we are trying to solve the problem: by introducing
> an ConceptInstance as well as a Concept.  This too can be seen at the
> above URL.
> 
> We are writing to ask this group to vet this idea.  We want to know, in
> your opinions, what are the ramifications of this re-model.

Why don't you use skos:broader, skos:narrower, skos:related or
mapping:broadMatch, mapping:exactMatch, mapping:majorMatch,
mapping:majorMatch, mapping:narrowMatch depending on how the concept
changed? Introducing a totally new ConceptInstance does not look very
consistent.

Greetings,
Jakob
Received on Tuesday, 29 August 2006 09:26:50 GMT

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