W3C home > Mailing lists > Public > public-esw-thes@w3.org > December 2007

Re: [SKOS]: [ISSUE 44] BroaderNarrowerSemantics

From: Simon Spero <ses@unc.edu>
Date: Mon, 17 Dec 2007 17:55:45 -0500
Message-ID: <1af06bde0712171455x1888e25cmab70e3be59c4a41@mail.gmail.com>
To: "Daniel Rubin" <rubin@med.stanford.edu>
Cc: "Sini, Margherita (KCEW)" <Margherita.Sini@fao.org>, "Ed Summers" <ehs@pobox.com>, public-swd-wg@w3.org, public-esw-thes@w3.org

On Dec 17, 2007 4:22 PM, Daniel Rubin <rubin@med.stanford.edu> wrote:

> Sorry, but I disagree with the suggestion that people define
> transitivity for themselves. SKOS should not leave such things
> undefined--to do so guarantees people will have different semantics
> for SKOS properties which will prevent interoperability.

I agree with Daniel here.  If broader is always transitive,  the
semantics are obvious, aligned with Z39.19,  and close to subsumption.

If broader *might* be intransitive, then any valid broader relations
that could otherwise have been inferred must be explicitly included in
the source vocabulary.

I would much rather see broader/narrower remain always transitive,
with different relationships  for  intransitive  cases.
An alternative would be to add cancel links (not-broader), and define
a non-monotonic semantics for SKOS (see e.g. Morgenstern, 1997) .
This approach is  probably out of skope.

Does anybody have a set of examples of valid relationships which they
believe should be covered by  'broader', but which can't be treated as
transitive?   What are the semantics? What are the characteristics
that distinguish these broaders from the transitive kind?  Is there an
ontologist in the house?

Simon


[Morgenstern, 1997]	Morgenstern, L. (1997). Inheritance comes of age:
Applying nonmonotonic techniques to problems in industry. In Pollack,
M., editor, Proceedings of the Fifteenth International Joint
Conference on Artificial Intelligence, San Francisco. Morgan Kaufmann.
Received on Monday, 17 December 2007 22:55:58 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:38:59 GMT