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Issue: versionIRI for SKOS-DL ontology?

From: Thomas Baker <tbaker@tbaker.de>
Date: Tue, 23 Nov 2010 13:05:10 -0500
To: public-esw-thes <public-esw-thes@w3.org>
Cc: fred@fgiasson.com, Ivan Herman <ivan@w3.org>, Guus Schreiber <schreiber@cs.vu.nl>, Alistair Miles <alimanfoo@gmail.com>, Antoine Isaac <aisaac@few.vu.nl>, Sean Bechhofer <sean.bechhofer@manchester.ac.uk>, Mike Bergman <mike@mkbergman.com>
Message-ID: <20101123180510.GA2860@octavius>
The following issue regarding the formal representation of
the "DL prune" of SKOS has been raised by Frederick Giasson
<fred@fgiasson.com>:

    The main problem is that the skos-core-dl version is using the 
    same ontology IRI as skos-code. Theoretically, there is no issue 
    in itself, but practically, in a OWL 2 environment, there are a 
    few issues related to this situation. As noted here [1]:

    "If an ontology has an ontology IRI but no version IRI, then a 
    different ontology with the same ontology IRI but no version IRI 
    /SHOULD NOT/ exist."

    Obviously, the current skos-dl ontology is breaking this rule. 
    While this new ontology versioning mechanism is part of OWL 2 and 
    was introduced after the last SKOS recommendation, I think that 
    this rule should be applied to OWL 1.1 ontologies as well, 
    without being explicit in the specification.

    The problem is that breaking this rule does affect some current 
    implementations of OWL 2 in different libraries/software. One 
    good example of this is with the OWLAPI and Protege 4.1 (at 
    least) as explained here [2] and check Timothy's answer [3]. I 
    don't know what the exact problem is, but I guess that it is due 
    to the fact that the OWL API does have a few built-in 
    understandings of the skos-core ontology IRI which clash with the 
    imported skos-dl version of the ontology. Since the ontology IRI 
    is the same, then it uses the skos-core ontology instead of the 
    skos-dl. I can also imagine that other frameworks/systems could 
    behave unpredictibly because of this broken assumption.

    So, I don't know what can be done, if anything. But certainly 
    that changing the ontology IRI for the skos-dl ontology could 
    help a lot. I am not sure you would be willing to add any OWL 2 
    constructs into this version of the ontology, but I would suggest 
    you consider using the owl:versionIRI predicate to specify the 
    specific version of that ontology.

    May I suggest something like:

          owl:versionIRI<http://www.w3.org/2004/02/skos/core/dl#>.

    [1] http://www.w3.org/TR/2009/REC-owl2-syntax-20091027/#Ontology_IRI_and_Version_IRI
    [2] http://protege-ontology-editor-knowledge-acquisition-system.136.n4.nabble.com/SKOS-labels-annotation-vs-datatype-properties-tt1840259.html#a1840259
    [3] http://protege-ontology-editor-knowledge-acquisition-system.136.n4.nabble.com/SKOS-labels-annotation-vs-datatype-properties-tt1840259.html#a1840495

-- 
Tom Baker <tbaker@tbaker.de>
Received on Tuesday, 23 November 2010 18:05:54 GMT

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