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[SKOS] proposed resolution for Issue 4 - BroaderNarrowerSemantics

From: Guus Schreiber <schreiber@cs.vu.nl>
Date: Tue, 15 Jan 2008 19:28:37 +0100
Message-ID: <478CFB55.8010107@cs.vu.nl>
To: SWD WG <public-swd-wg@w3.org>

All,

Based on the post-telecon discussion of today, I'm proposing the resolution below.

Guus

Proposed RESOLUTION for Issue-44 BroiaderNarrowerSemantics
http://www.w3.org/2006/07/SWD/track/issues/44

1. Given that:

- in the thesaurus world BT (BroaderTerm) is used to assert a concept
as the *direct* parent in of another concept in a BT/NT hierarchy, and
- we prefer the skos:broader to resemble as closely as possible the
intended meaning and/or accepted practice of using BT

we RESOLVE that skos:broader is *not* a transitive property.
 
2. Given that:

- in the thesaurus world there is  clear need to be able to talk about
the transitive closure of the BT relation, and
- it would be confusing if SKOS (given its RDF/OWL baseline) would
*not* predefine such a transitive interpretation of BT, and
- for reasons of logical consistency (see note below) a transitive version of BT
necessarily needs to be defined as a *superproperty* of its
direct-parent variant 

we RESOLVE that the property skos:broaderTransitive is added to the
SKOS vocabulary, and that this new property is defined as a
owl:Transitive property and as a superproperty of skos:broader.

3. Identical resolutions hold for the inverse properties skos:narrower
and skos:narrowerTransitive. 


NOTE: The extension of a transitive variant B of a property A always
contains the same or more instances than the extension of property A.
Therefore, B cannot be defined as a subproperty of A (unless A and B
are the same, which is not what we intend when introducing B).  So,
transitivity is *not* automatically inherited over the subproperty
relationship. For a description of a similar modeling pattern, see
the SWBPD note on representing simple part-whole relations [1].

[1] http://www.w3.org/2001/sw/BestPractices/OEP/SimplePartWhole/index.html


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Received on Tuesday, 15 January 2008 18:28:55 UTC

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