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Re: Change proposal

From: Alistair Miles <a.j.miles@rl.ac.uk>
Date: Tue, 30 May 2006 16:34:33 +0100
Message-ID: <447C6609.4090007@rl.ac.uk>
To: public-esw-thes@w3.org

Hi Mark,

I'm glad you posted this, I've been meaning to comment on this for 
ages and just haven't got round to it. Basically, what you've got 
below looks to me like it should be broken into maybe 10 separate 
items for the issues list. I keep meaning to have a go at separating 
the issues myself, I hope to get round to it asap.

I tried to summarize some of the issues while drafting a paper for the 
dublin core conference recently. I ended up dropping the discussion 
from the paper, but the original content is online, see:

http://isegserv.itd.rl.ac.uk/public/skos/press/dc2006/thesaurus.html

- note that this and everything linked from it is *extremely rough 
work*, certainly not citable in any academic sense, and may change 
totally or disappear at any time.

Cheers,

Al.



Mark van Assem wrote:
> 
> Hi all,
> 
> Alistair requested me some time ago to write a "change proposal" to
> document the issue of not having URIs for terms in SKOS (instead they
> are rdfs:Literals).
> 
> Basically this is to record the trade-offs of both solutions, because we
> could not agree on what action to take.
> 
> I am still unconvinced that it is better to not have URIs for terms, but
>   as the SWBP WG is at its end, I will settle for just recording the issue.
> 
> Alistair, can you add this to the CP list [1] (provided the text is ok)?
> 
> With regards,
> Mark.
> 
> [1]http://www.w3.org/2004/02/skos/core/proposals
> 
> ----------------------------------------------------------------------
> Change Proposal
> 
> * Title: Additional properties of terms
> 
> * Type: known requirement for which solution has trade-offs
> 
> * Issue/Requirement
> 
> SKOS Core uses a class skos:Concept to represent "concepts" and
> skos:prefLabel/skos:altLabel to represent "terms" or "labels" that
> represent the concept lexically. Some concept schemes that are used in
> practice represent additional information on terms, such as [1]:
> 
> - scope notes for terms, also referring to other terms to use
> - lexical information about the term
> - scope of usage of the lexical term
> - etymological information
> - register-related information
> - standardization related information
> - local identifiers for terms
> - date of creation
> - last date of modification
> - term abbreviations
> - source of the term (if the concept scheme is built up from other
> sources)
> - definitions of terms
> 
> However, because the range of skos:prefLabel/skos:altLabel is
> rdfs:Literal it is not possible to attach these kinds of information
> to terms (properties cannot have rdfs:Literal as domain).
> 
> 
> * Possible Solution(s)
> 
> Provide a way to represent "terms" as instances of a class so that
> additional properties can be attached to them.
> 
> - introduce a class skos:Term;
> - rename skos:prefLabel/skos:altLabel to skos:prefTerm/skos:altTerm
> - Change the range of these properties into skos:Term
> 
> With this solution in place it is possible to provide a set of common
> term-centric properties in SKOS Core and/or provide superproperties that
> can be locally extended.
> 
> * Trade-offs
> 
> + less information loss in conversion of concept schemes that
>   contain these kinds of information on terms
> - model becomes more complex
> - most retrieval purposes are already covered by the existing model
>   (benefits of new model for information retrieval may be limited)
> 
> 
> * Proposed action
> 
> Future SKOS activities should reconsider this Issue, make a definitive
> choice and provide an explanation of the particular choice, detailing
> the above mentioned trade-offs.
> 
> * References
> 
> [1]http://lists.w3.org/Archives/Public/public-esw-thes/2005Nov/0000.html
> 
> 
> 

-- 
Alistair Miles
Research Associate
CCLRC - Rutherford Appleton Laboratory
Building R1 Room 1.60
Fermi Avenue
Chilton
Didcot
Oxfordshire OX11 0QX
United Kingdom
Web: http://purl.org/net/aliman
Email: a.j.miles@rl.ac.uk
Tel: +44 (0)1235 445440
Received on Tuesday, 30 May 2006 15:35:05 GMT

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