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RE: [SKOS] RE: ISSUE-33: GroupingConstructs

From: Stella Dextre Clarke <sdclarke@lukehouse.demon.co.uk>
Date: Tue, 27 Mar 2007 11:35:05 +0100
To: "'Miles, AJ \(Alistair\)'" <A.J.Miles@rl.ac.uk>, "'SWD WG'" <public-swd-wg@w3.org>
Cc: <public-esw-thes@w3.org>
Message-ID: <001101c7705b$9929d960$0300000a@DELL>

I've just been looking at your blog statement at
and I think it is a useful and accurate description of the situation
we're trying to work through.

You gave a caution about possible inconsistencies between ISO 2788 and
BS 8723-2, And I'll now try and cast a little light on that.

The use of the term "facet indicator" in ISO 2788 was probably a
mistake. We deliberated over this while developing BS 8723, and spoke to
one of the persons who was probably influential in putting this term
into ISO 2788. After careful consideration, she was able to advise us to
drop the term "facet indicator" in this context. BS 8723-2 instead
speaks of "characteristics of division", in line with current thinking
on faceted classification (at least as it is practised in the UK!).

The other small inconsistency you were probably referring to concerns
the second type of node label, where characteristics of division are not
involved. In this second type, the node labels introduce "different
types of concepts" according to ISO 2788, or "new facets" according to
BS 8723. I don't see any discrepancy here, since a facet is defined as a
"grouping of concepts of the same inherent category".  (It is possible
that the ISO 2788 committee was trying to avoid getting too deeply
dependent on the specialist terminology of the faceted classification

So as far as ISO 2788 and BS 8723 are concerned, I believe we have
pretty good continuity. But the AAT with its guide terms is definitely
different.  The introduction to the printed thesaurus states that guide
terms "are also called node labels or facet indicators by some
thesauri." Well, that may be true of some thesauri, but not of ISO 2788
or BS 8723! The way the AAT does things was very carefully planned for
its own context, subtly different from many information retrieval
applications and the conventional thesaurus. For example, if you look at
the AAT online or in print, you won't find the tags "BT" or "NT"
anywhere (although you do find "RT" occasionally in the printed
version). So they nowhere fall into the trap of presenting a guide term
as an "NT" of one of the descriptors recommended for indexing. However,
they say that guide terms "are used as broader terms to some groups of
descriptors when there is no broader term to bring the grouping term
together. ....In addition to serving as broader terms, many guide terms
define the characteristics of division by which a listing of narrower
terms is clustered." 

You could summarise the above by saying that there is a lot of common
ground between AAT guide terms and ISO 2788 node labels. For example,
there are two different types of guide terms, and the AAT makes it
abundantly clear that the guide terms are not to be used for indexing.
But the requirement for some guide terms to serve as broader terms
(though only for presentation/grouping purposes, not for indexing) is an
important difference.

I'm not sure how you get SKOS to work well with both approaches
All the best!

Stella Dextre Clarke
Information Consultant
Luke House, West Hendred, Wantage, Oxon, OX12 8RR, UK
Tel: 01235-833-298
Fax: 01235-863-298

-----Original Message-----
From: public-esw-thes-request@w3.org
[mailto:public-esw-thes-request@w3.org] On Behalf Of Miles, AJ
Sent: 26 March 2007 13:06
Cc: public-esw-thes@w3.org
Subject: [SKOS] RE: ISSUE-33: GroupingConstructs

Guus asked me to suggest an issue to open at the next telecon. I



Alistair Miles
Research Associate
CCLRC - Rutherford Appleton Laboratory
Building R1 Room 1.60
Fermi Avenue
Oxfordshire OX11 0QX
United Kingdom
Web: http://purl.org/net/aliman
Email: a.j.miles@rl.ac.uk
Tel: +44 (0)1235 445440 
> -----Original Message-----
> From: public-swd-wg-request@w3.org
> On Behalf Of SWD Issue Tracker
> Sent: 26 March 2007 12:58
> To: public-swd-wg@w3.org
> Subject: ISSUE-33: GroupingConstructs
> ISSUE-33: GroupingConstructs
> http://www.w3.org/2006/07/SWD/track/issues/33
> Raised by: Alistair Miles
> On product: SKOS
> Thesaurus standards describe the use of "node labels" for convenient 
> grouping and display. Many thesauri use node labels in this way. Some 
> thesauri use "guide
> terms" for a similar purpose. In some social tagging systems, tags can
> be
> grouped into "bundles".
> The current vocabulary support in SKOS (called "Collections") for
> kinds of
> grouping construct is broken, in that it introduces a contradiction
> the
> SKOS specifications.
> See further information at:
> http://www.w3.org/2006/07/SWD/wiki/SkosDesign/GroupingConstructs
Received on Tuesday, 27 March 2007 10:36:27 UTC

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