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Re: [SKOS] A new proposal for ISSUE-39 ConceptualMappingLinks

From: Antoine Isaac <aisaac@few.vu.nl>
Date: Mon, 10 Dec 2007 11:50:01 +0100
Message-ID: <475D19D9.3080009@few.vu.nl>
To: Stella Dextre Clarke <sdclarke@lukehouse.demon.co.uk>
CC: "'Miles, AJ \(Alistair\)'" <A.J.Miles@rl.ac.uk>, public-swd-wg@w3.org, public-esw-thes@w3.org

Dear Stella,

> Sorry to come in late. And sorry I'll continue to be here one day, gone
> the next, but I guess we all have distractions to tear us away... This
> response is built on one of Alistair's.
>   

The fact that you come late does not diminish the value of your coming 
;-) Thanks a lot.

>> First, I'd like to try to summarise the minimum consensus 
>> position. I.e. what's the least we can agree on? ...
>>
>> Minimum consensus: Using SKOS, it should be possible to state 
>> broader, narrower, related and exact (equivalent) semantic 
>> links between concepts from different concept schemes. 
>>     
> Agreed. These relationships have stood the test of time in the context
> of ISO 2788, BS 5723, ANSI/NISO Z39.19, going back to 1974, for use
> within a single concept scheme. They are widely used and understood.
> They were always intended to be used for paradigmatic rather than
> syntagmatic relationships (in other words, they should apply in a broad
> range of contexts, not just on the basis of co-occurrence in a
> particular document or set of documents) therefore they ought to be
> applicable for use across a range of applications, vocabularies and
> resource collections. There seems every reason to mirror them when
> designing mappings between vocabularies. (But using a syntax that makes
> it clear they are being applied across schemes, not within a scheme.)
>   

I hope suffixing the relation names with "Match" fits such a concern

>> Moving beyond this, I think there a number of issues with our 
>> current proposals which need further discussion.
>>
>> I'd like to identify three sub-issues here, which could be 
>> discussed independently. I'll try to separate them out here, 
>> then respond in more detail to each one in separate mails.
>>
>> (ISSUE-39A) Should "grouping" constructs for mapping be 
>> included, and if so, what are their semantics?
>>     
>
> This topic seems to be about mapping from term A to a combination of
> Term B and Term C, where the combination could be done with Boolean AND,
> OR, or NOT. 
> Somebody asserted that BS 8723 allows use of AND but deprecates OR. This
> is only partly true.  BS8723-2, which applies only to relationships
> within a thesaurus, indeed recommends avoiding the use of "A USE B OR
> C", and explains how to do so. It encourages use of "A USE B + C" where
> appropriate (but caution: in practice there is not much commercially
> available  software that can handle this complex 3-way relationship) and
> it says nothing at all about NOT. In fact, it steers clear of "AND" too,
> preferring the symbol "+", so as not to get hung up on Boolean algebra.
> BS8723-4, the part of the standard that has just been published this
> December, deals with mappings between vocabularies and has a couple of
> pages of discussion on one-to-many and many-to-one mappings (which it
> does not simply equate to use of Boolean operators. Instead it
> recommends use of symbols + and | ). One of the problems is that the way
> they work  for conversion of search statements is different from the way
> they work  for conversion of index terms. 
> I think it was Margherita who made the point that many-to-one is hard to
> handle, and effectively means that complex mappings usually work well in
> one direction only (i.e. one-to-many). The SKOS community might want to
> study some good use cases before reaching conclusions on this issue.
>   

Indeed! If you have some links we would be very interested. I will try 
to come back to you when we study the issues on coordination (which are 
less central on our agendas these weeks :-(
Notice that since we have to coin URIs for SKOS construct, I think we 
will not be able to opt for something like "|" if we want to represent 
these things.

[Comments on the last part of you mail coming...]

Best,

Antoine


>> (ISSUE-39C) What's the difference between "related" and 
>> "overlapping"? Is there enough precedent to justify a new 
>> property for "overlapping"?
>>     
> Three options have been discussed, namely related, overlapping and
> inexact. I guess I am biased by long familiarity with "related". I feel
> it is sufficient to choose just one, and that it should be "related". It
> seems to me that "overlapping" is a subset of related, and harder for
> simple people to use in a hurry. The definition of the associative
> relationship (RT/RT) in a thesaurus has always been subjective, which
> some people see as a failing (but I see it as a strength, so long as we
> recognise that the fuzziness is present). 
>
> Just by the way, I agree with what seems now to be the general choice to
> drop majorMatch and minorMatch. I liked the sound of these when they
> were first proposed, and they could still have uses in the context of
> particular predefined document collections, where syntagmatic
> relationships have applications. But they are not so workable if you
> want the mappings to serve for collections that may grow in
> unpredictable directions.
Received on Monday, 10 December 2007 10:50:10 GMT

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