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Re: [SKOS] thesaurus USE patterns

From: Mark van Assem <mark@cs.vu.nl>
Date: Wed, 14 Feb 2007 18:31:19 +0100
Message-ID: <45D34767.2010300@cs.vu.nl>
To: public-esw-thes@w3.org
CC: Jakob Voss <jakob.voss@gbv.de>

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.

-- 
  Mark F.J. van Assem - Vrije Universiteit Amsterdam
        markREMOVE@cs.vu.nl - http://www.cs.vu.nl/~mark
Received on Wednesday, 14 February 2007 17:32:07 GMT

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