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Re: [SKOS] thesaurus USE patterns

From: Bernard Vatant <bernard.vatant@mondeca.com>
Date: Thu, 15 Feb 2007 11:33:11 +0100
Message-ID: <45D436E7.60201@mondeca.com>
To: Mark van Assem <mark@cs.vu.nl>
Cc: public-esw-thes@w3.org, Jakob Voss <jakob.voss@gbv.de>

Hi Mark

I agree there is no question one needs at some point a "Term" class to 
deal with terminological attributes.
We have an ongoing project in Mondeca with a multilingual vocabulary 
where we needed to represent among other things grammatical qualifiers 
such as gender etc.
Those are clearly attached to terms, not to concepts.
"Sun'' is neutral in english, "Soleil" is masculine in french, "Sonne" 
is feminine in german.
So we introduced a Term class, and link all the terms to the concept 
exactly the way you suggest (using proprietary classes and attributes so 
far).

Now the question is : does that belong to SKOS (core) scope? looks like 
borderline. And if we open this door, who knows what is likely to enter ...
In a modular approach, seems to me terminological aspects should be 
dealt in later on in some specific extension, SKOS-Term, whatever.

Problem if we include skos:Term in SKOS core, looks like we have to 
revisit many things, e.g. prefLabel and altLabel.
Some will use them as they stand now (datatype properties) and other 
will use "hasTerm" (object properties). Making further federation of 
such vocabularies very tricky.
And I think it would be a very bad idea to enforce "term reification" 
(so to speak) by getting rid of prefLabel and altLabel as they stand.

Bernard
>
> Hi,
>
>> but I don't see the advantage of it. The second point is right - "Z" is
>> not a concept but a term and currently skos does not allow it to be a
>> subject - but the whole USE-relationship is about terms anyway.
>
> Long ago I proposed the inclusion of a skos:Term class that could be 
> used to solve this problem. It is very straightforward then to manage 
> the different kinds of links between terms, concepts and coordinations.
>
> Having skos:Term allows to represent terms separate from concepts that 
> use it. Terms are then roughly equivalent to WordNet's WordSenses and 
> concepts to WordNet's Synsets. This allows all kinds of relationships 
> between Synsets/concepts (which carry non-lexical meaning) and 
> Terms/WordSenses (which do carry lexical meaning). This includes the 
> various USE relationships. USE/USEFOR becomes "hasTerm" (or separated 
> into prefTerm and altTerm but I dont think the pref/alt distinction to 
> be appropriate anymore) in the example below (adapted from Jacob's).
>
> -------------------------------------------------
> :abc a skos:Term ;
>     rdfs:label "C Programming Language" .
>
> :def a skos:Term ;
>     rdfs:label "C" .
>
> :ghi a skos:Term ;
>     rdfs:label "Vitamin C" .
>
> :jkl a skos:Term ;
>     rdfs:label "C" .
>
> :c1 a skos:Concept;
>     skos:hasTerm :abc ;
>     skos:hasTerm :def .
>
> :c2 a skos:Concept.
>     skos:hasTerm :ghi ;
>     skos:hasTerm :jkl .
> -------------------------------------------------
>
> And defining those problematic relationships becomes simple
>
> * USE X + Y
>
> -------------------------------------------------
> coal mining USE coal + mining
>
> :cm a skos:Term ;
>     rdfs:label "coal mining" .
>
> :c a skos:Term ;
>     rdfs:label "coal" .
>
> :m a skos:Term ;
>     rdfs:label "mining" .
>
>
> :conceptc a skos:Concept;
>     skos:hasTerm :c .
>
> :conceptm a skos:Concept;
>     skos:hasTerm :m .
> -------------------------------------------------
>
>
> ... and finally the relationship:
>
> -------------------------------------------------
> :use1 a skos:UseAND ;
>     skos:source :cm ;
>     skos:target skos:ConceptAND [ skos:member :c ; skos:member :m ].
> -------------------------------------------------
>
> Because Terms are not used for indexing, the combination "coal mining" 
> as a Term can point to the appropriate coordinated concepts "coal + 
> mining".
>
>
> * USE X OR Y
>
> grinding mill
>   USE grinding house OR grindery
>
> ... well very similar, without stating the obvious concept definitions:
>
> -------------------------------------------------
> :use2 a skos:UseOR ;
>     skos:source :gm ;
>     skos:target skos:ConceptOR [skos:member :gh ; skos:member :g].
> -------------------------------------------------
>
> Of course we discussed this kind of thing before and the tradeoff is 
> that this makes SKOS more complex, and the exposing of Terms as 
> entities in their own right might be open to abuse (e.g. start 
> indexing stuff with Terms). But it also allows more fine grained 
> mappings and man'ment info to be attached to them.
>
> Cheers,
> Mark.
>

-- 

*Bernard Vatant
*Knowledge Engineering
----------------------------------------------------
*Mondeca**
*3, citÚ Nollez 75018 Paris France
Web:    www.mondeca.com <http://www.mondeca.com>
----------------------------------------------------
Tel:       +33 (0) 871 488 459
Mail:     bernard.vatant@mondeca.com <mailto:bernard.vatant@mondeca.com>
Blog:    Lešons de Choses <http://mondeca.wordpress.com/>
Received on Thursday, 15 February 2007 10:33:23 GMT

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