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[SKOS] on concept validity and re-use (was Re: REVISION SKOS Simple Knowledge Organization System Reference)

From: Antoine Isaac <aisaac@few.vu.nl>
Date: Mon, 18 Aug 2008 10:57:24 +0200
Message-ID: <48A93974.7090307@few.vu.nl>
To: "Sini, Margherita (KCEW)" <Margherita.Sini@fao.org>
CC: public-swd-wg@w3.org, SKOS <public-esw-thes@w3.org>

Hi Margherita,

Reacting on some points of your (very interesting btw) review

> I also propose for other future releases of SKOS that the WG could take in
> consideration the notion of context of validity of concepts or relationships,
> maybe later on adding the notion of "extent" or "validity"... E.g. a concept
> or term (label) may be valid only in a specific geographical area or at a
> given time, and a relationship may be valid for a specific culture only. ( I
> can provide examples if needed, but as i said ... this may be for other
> releases... if the group think is good to adapt this).

> 4.6.1. Closed vs. Open Systems
> I may have a problem with this <<<<MyConcept> takes part in two different
> concept schemes>>>... in fact this its true.... BUT.... if we go to the
> labels level... we may have to keep in kind that the same concept may be
> lexicalized differently in different schemes... How this will be represented
> in SKOS? there is no way yet (maybe?) to express that the labels attached to
> an skos:Concept may be from different schemes.... And what about the URI of
> the skos:Concept? will it be the one from one scheme (e.g. <skos:Concept
> rdf:about="http://www.fao.org/aims/aos/agrovoc#c_1939">) or from the other
> scheme (e.g. <skos:Concept
> rdf:about="http://agclass.nal.usda.gov/nalt#cows">)?

This is an interesting point that would deserve further discussion 
(maybe by the way the SKOS list is more adapted for that). I guess also 
that it's not urgent, but will you provide these examples in the future?
At first glance I would have actually assumed an 'essential' view on 
semantic relationship and labelling properties. They define the esence 
of a concept, and therefore if a relation is not always valid (at least 
within one concept scheme) then it might reflect the need to have two 

> <<<This flexibility is desirable because it allows, for example, new concept
> schemes to be described by linking two or more existing concept schemes
> together.>>> but if it is so.... why there are the mapping elements
> exactMatch, narrowMatch, etc... which can be used to link two or more
> existing concept schemes? This second solution infact, would resolve the
> problem of keeping the 2 distinc URi, be able to lexicalized differently
> concepts, but expressing that a concept may take part on 2 different schemes.

The difference here is that if you have one concept in two schemes, it 
should really be a case of re-use: when including the concept C from a 
CS A, the designer of a CS B agree that the C entirely matches their needs.
For mappings, the concepts may have been created independentely, and 
have to be reconciled a posteriori for a specific application -- which 
will be most often different from the ones that motivated the design of 
A and B


Received on Monday, 18 August 2008 08:57:59 UTC

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