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RE: SKOS comment: change of namespace (ISSUE-117)

From: Alistair Miles <alistair.miles@zoo.ox.ac.uk>
Date: Thu, 31 Jul 2008 18:34:34 +0100
To: "'Simon Spero'" <ses@unc.edu>
Cc: <public-swd-wg@w3.org>, <public-esw-thes@w3.org>
Message-ID: <004201c8f333$b2b3d230$181b7690$@miles@zoo.ox.ac.uk>

Hi Simon,

If you consider that the tradition thesaurus BT relationship is currently
modeled in SKOS not by any single property, but by two properties, both
skos:broader and skos:broaderTransitive, then I believe the current design
is commensurate with your point of view.

I.e. skos:broader models the asserted BT relationship,
skos:broaderTransitive represents BT relationships that are either asserted
or can be inferred via the transitive closure. 

Sorry I don't have time for more right now. This feature will be marked "at
risk" in the last call working draft, so we won't close the door just yet.
I'm off for a week, but I look forward to getting into this issue in more
detail when I get back. I especially want to revisit the justification for a
parent/ancestor property pair, independently of any discussion and confusion
around naming. 

Thanks for the very educated and interesting debate.

Kind regards,


Alistair Miles
Senior Computing Officer
Image Bioinformatics Research Group
Department of Zoology
The Tinbergen Building
University of Oxford
South Parks Road
United Kingdom
Web: http://purl.org/net/aliman
Email: alistair.miles@zoo.ox.ac.uk
Tel: +44 (0)1865 281993

> -----Original Message-----
> From: public-swd-wg-request@w3.org [mailto:public-swd-wg-
> request@w3.org] On Behalf Of Simon Spero
> Sent: 28 July 2008 20:27
> To: Alistair Miles
> Cc: Laurent LE MEUR; public-swd-wg@w3.org; public-esw-thes@w3.org
> Subject: Re: SKOS comment: change of namespace (ISSUE-117)
> On Fri, Jul 25, 2008 at 8:00 AM, Alistair Miles
> <alistair.miles@zoo.ox.ac.uk> wrote:
> 	The argument against sticking with the old namespace is that the
> semantics have changed significantly. I don't think that's necessarily
> true. The only
> 	change to the semantics of an existing element is the change of
> skos:broaderto not being transitive. However, all data I know of
> currently published
> 	fits perfectly well with the usage pattern that "skos:broader is
> used to assert a direct hierarchical link between two concepts" -- and
> hence is perfectly consistent with the new data model. If anyone can
> provide a counter-example I'd be very grateful.
> http://lcsh.info/
> The Hierarchical Relationship: Broader Topics and Narrower Topics
> [...]
> A heading is normally linked to one immediately next to it in the
> subject heading hierarchy. Since the referenced headings are linked in
> turn to ther headings, reference for distant relationships are no
> longer made. References leading to two or more levels in a hierarchy
> reflect an obsolete practice.
> Library of Congress Subject Headings (22nd edition) vol. 1, p. x
> This policy corresponded to the introduction of explicit BT and NT
> relationship designators, and is incrementally implemented. This
> instruction is only plausible because the BT relationship is transitive
> ("No matter what the level at which one enters the hierarchy, one can
> follow either the  BT or NTs to find the broadest or most specific
> headings" (ibid)
> In current LCSH, we have separate, explicit assertions that:
> 1: Technological innovations BT Inventions        (TI  BT I)
> 2: Inventions BT Creative ability in technology    (I BT CAIT)
> 3: Technological  innovations BT Creative ability in technology   (TI
> Under the tranditional meaning  of BT, assertion 3 is uncessary, due to
> the semantics of hierarchical relationships.  Under LC rules, which are
> semantic preserving, it is safe to remove this link.
> Removing it, we have
> Under the original, correct, skos  semantics, broader operates the same
> BT.
> TI broader I,  I broader CAIT |= TI broader I, I broader CAIT, TI
> broader CAIT
> Under the new semantics
> TI "broader" I, I "broader" CAIT |/= TI broader CAIT
> The semantics of the new "broader" are *clearly* not the same as BT, or
> the correct broader.
> IF you want to keep the same namspace, rename the new
> "broaderTransitive" relationship to "broader", and rename the new
> "broader" relationship to "directllyAssertedBroader".
> The BT relationship is intrinsically hiearachical and thus transitive.
Received on Thursday, 31 July 2008 17:35:18 UTC

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