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Issue with collections

From: Miles, AJ \(Alistair\) <A.J.Miles@rl.ac.uk>
Date: Thu, 11 Aug 2005 18:32:45 +0100
Message-ID: <677CE4DD24B12C4B9FA138534E29FB1D0ACCEB@exchange11.fed.cclrc.ac.uk>
To: <public-esw-thes@w3.org>

Hi all,

I just realised we have an issue with current recommended usage of the 'meaningful collections' bit of SKOS Core [1].  It goes like this:

The whole point of the skos:Collection class was so that we could *avoid* representing a node label such as 'milk by source animal' or 'people by age' as a label for a concept.  The current consensus is that node labels are *not* labels for concepts, and should not be modelled as such.

However, to allow node labels to still be rendered as part of a hierarchical display, we had to invent the extremely cunning skos:CollectableProperty class, with the associated 'collectable properties rule', see [2].

But, if we allow stuff like ...

@prefix ex: <http:///www.example.com/concepts#> .
# other namespaces as standard

ex:milk a skos:Concept;
  skos:narrower _:node1;

_:node1 a skos:Collection;
  rdfs:label 'Milk by source animal';
  skos:member ex:goatmilk;
  skos:member ex:cowmilk;
  skos:member ex:yakmilk;

... then because ...

skos:narrower rdfs:subPropertyOf skos:semanticRelation .

... and ...

skos:semanticRelation rdfs:range skos:Concept .

... we end up with the inference that ...

_:node1 a skos:Collection, skos:Concept .

... which is the very thing we were trying to avoid - doh!

I'm not sure how best to fix this right now, I'll have a think when I get back from hols.



[1] http://www.w3.org/TR/2005/WD-swbp-skos-core-guide-20050510/#seccollections
[2] http://www.w3.org/TR/2005/WD-swbp-skos-core-guide-20050510/#seccollectable
Alistair Miles
Research Associate
CCLRC - Rutherford Appleton Laboratory
Building R1 Room 1.60
Fermi Avenue
Oxfordshire OX11 0QX
United Kingdom
Email:        a.j.miles@rl.ac.uk
Tel: +44 (0)1235 445440
Received on Thursday, 11 August 2005 17:32:50 UTC

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