- From: Antoine Isaac <aisaac@few.vu.nl>
- Date: Mon, 10 Dec 2007 11:50:01 +0100
- 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 UTC