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Re: [SKOS] Possible issue: Uniqueness of skos:prefLabel [was Re: [SKOS] inconsistency between Guide and Specification

From: Antoine Isaac <aisaac@few.vu.nl>
Date: Tue, 27 Feb 2007 15:14:54 +0100
Message-ID: <45E43CDE.30507@few.vu.nl>
To: Guus Schreiber <schreiber@cs.vu.nl>
CC: public-swd-wg@w3.org

Guus Schreiber a écrit :

>
> Antoine Isaac wrote:
>
>> Hi Guus,
>>
>> I'm not really convinced by this argument, for two reasons:
>> - relevance to domain practice: even if a motivation for the 
>> constraint in ISO and other thesaurus modelling approaches 
>> (especially term-based ones, which are still encountered in many 
>> situations) was this reference uniqueness, there are also strong 
>> normalization issues underway. People managing thesauri are often 
>> spending a lot of time distilling *the* term that embodies the 
>> concept in the best way. And while standard database have been 
>> allowing for unique keys for decades, they still keep to this 
>> constraint on the labels.
>
>
> And nothing prevents them from keeping on doing so. My point is that I 
> see no reason to make this customary practice a hard constraint for 
> all users of SKOS. Why would we want to prevent some thesaurus 
> builder,who wants to have multiple preferred labels in the same 
> language, to use SKOS?

Let's be honnest: while I see the motivation for having the constraint, 
I don't see really what modelling gains could be obtained by multiple 
preferred labels. But of course if Alan has a case I will re-consider my 
position.

>
> Anyway. the is no way to express this cardinality constraint in 
> RDF/OWL while taking the multi-lingual aspect into account .

True for the cardinality constraint. But for the uniqueness one, we 
could still use inverseFunctionalProperty, couldn't we? It goes into OWL 
Full for datatype properties, but does the trick it seems. Hmm, well, 
ok, there will be problems if we have several concept schemes 
introducing distinct concepts with same labels, which is likely to 
happen on the web :-(

Cheers,

Antoine

>>
>>>
>>>
>>>
>>> Guus Schreiber wrote:
>>>
>>>>
>>>> While trying to write down a resolution for the relationship 
>>>> between labels I found:
>>>>
>>>> in the Core Guide, section on Multilingual La belling [1]
>>>>
>>>> [[
>>>>   It is recommended that no two concepts in the same concept scheme 
>>>> be given the same
>>>>   preferred lexical label in any given language.
>>>> ]]
>>>>
>>>> in the Core Specification, table of prefLabel [2]
>>>>
>>>> [[
>>>>   No two concepts in the same concept scheme may have the same 
>>>> value for skos:prefLabel
>>>>   in a given language.
>>>> ]]
>>>
>>>
>>>
>>> I see no need for placing a constraint on the uniqueness of 
>>> skos:prefLabel. While some/many vocabularies will actually abide to 
>>> this, the URI of the concept the label is related already ensures 
>>> uniqueness of the concept being identified (which I assume was the 
>>> reason for including this constraint in the ISO spec). I also 
>>> suggest that there is no need to place cardinality constraints on 
>>> skos:prefLabel.
>>>
>>> The underlying rationale is that we should refrain from 
>>> overcommiting the SKOS specification when there is no clear need.
>>>
>>> I want to raise this as an issue and propose the above as a resolution.
>>>
>>>>
>>>> The weaker constraint in the Guide makes sense to me. I will most 
>>>> likely propose an even weaker version in my resolution.
>>>>
>>>> Guus
>>>>
>>>>
>>>>
>>>> [1] 
>>>> http://www.w3.org/TR/2005/WD-swbp-skos-core-guide-20051102/#secmulti
>>>> [2] http://www.w3.org/TR/swbp-skos-core-spec/#prefLabel
>>>
>>>
>>>
>>
>
Received on Tuesday, 27 February 2007 14:14:58 GMT

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