- From: Bernard Vatant <bernard.vatant@mondeca.com>
- Date: Fri, 03 Aug 2007 12:17:01 +0200
- Cc: 'Antoine Isaac' <aisaac@few.vu.nl>, public-esw-thes@w3.org, public-swd-wg@w3.org
Hi all Just to say +1 with Stella, Doug and Ceri on this. I've already defended this view previously, so won't repeat the arguments. See below posts http://lists.w3.org/Archives/Public/public-esw-thes/2007Jun/0034.html http://lists.w3.org/Archives/Public/public-esw-thes/2007Jul/0015.html Bernard Stella Dextre Clarke a écrit : > Just a brief note to agree with Libo and with Doug and Ceri that it is > vital (for human users as well as for automated applications) to be able > to distinguish easily between an inter-vocabulary mapping and an > intra-vocabulary relationship. The forthcoming BS8723-4 has some > recommendations for the style of tags which should be used to display > the mappings and the relationships to users. > Stella > > ***************************************************** > Stella Dextre Clarke > Information Consultant > Luke House, West Hendred, Wantage, Oxon, OX12 8RR, UK > Tel: 01235-833-298 > Fax: 01235-863-298 > SDClarke@LukeHouse.demon.co.uk > ***************************************************** > > > > >> -----Original Message----- >> From: public-esw-thes-request@w3.org >> [mailto:public-esw-thes-request@w3.org] On Behalf Of L.Si@lboro.ac.uk >> Sent: 02 August 2007 16:41 >> To: Tudhope D S (AT); Antoine Isaac >> Cc: public-esw-thes@w3.org; public-swd-wg@w3.org >> Subject: Re: [SKOS] RE : Skos mapping issues >> >> >> >> Dear All, >> >> i just want to say. ...In some situations, end-users may >> prefer to have a direct look at the mapping and mapping >> relationship between two concepts from different KOS. If >> we use the skos:broader to represent the inter-mapping >> relationship, the end users may be confused with the >> sources of KOSs. >> >> In many cases, it is very easy for users to misunderstand >> the inter-mappings established as intra-mappings. Thus, I >> strongly suggest the mapping should be particularly >> presented to the end-users with some clear inter-mapping >> relationships, (e.g. map:broader, map:majorMatch, etc.). I >> cannot see any benefit from using skos:broader and >> skos:narrower to represent them from end-users' points of >> view. >> >> There are a lot of project developed based on mapping work >> to improve the interoperability between KOS, such as, >> Renardus, HILT, MACS, etc. However, it is difficult to >> find some excellent services. I just want to ask how the >> end-users can benefit from the mapping? Will the mapping >> effort be replaced by merging to a metathesaurus, or >> mapping to a single ontologies? >> >> Kind regards >> >> Libo >> >> Loughborough University >> >> >> >> On Thu, 2 Aug 2007 12:34:28 +0100 >> "Tudhope D S (AT)" <dstudhope@glam.ac.uk> wrote: >> >>> Hi Antoine >>> re your points on skos:broader, in_scheme, mapping and >>> KOS extensions: >>> >>> We agree it is important to know that a concept, or KOS >>> fragment, belongs to a particular scheme. Skos:inscheme >>> appears a reasonable way of achieving this, within the >>> constraints of a binary relational modelling framework >>> like RDF. >>> >>> This is a separate issue from applicability of BT across >>> schemes. We do see a difference in the semantics of an >>> inter-vocab relationship from an intra BT within a vocab. >>> >>> In our view, there are 2 quite different kinds of >>> relationship being discussed - local vocabulary >>> extensions and inter thesaurus mappings between separate >>> concept schemes (KOS). >>> >>> To establish a BT relationship the child concept must >>> fall entirely within the scope and context of the parent >>> concept. When creating local vocabulary extensions, the >>> new local concept scheme should fully align with the >>> scope and context of the vocabulary being extended - as >>> it is the intention to supplement the original with finer >>> detail. In this case you might reasonably employ >>> skos:broader in our view. The provenance (eg in-scheme) >>> is still important - any local extension may be >>> muddled/controversial etc and an application may decide >>> not to make use of it. >>> >>> This is not the same as inter thesaurus mapping though. >>> There is likely to be an inherent mismatch in context and >>> scope between 2 entirely separate KOS created for >>> different purposes. A thesaurus (or related KOS) >>> represents a particular perspective, considered useful >>> for the various information retrieval purposes on a >>> domain at a particular point in time. The concepts, the >>> relationships between them and the language used to >>> describe them are all contextually relative to the >>> environment in which they are established. In this >>> situation, we would argue that skos:broader should not be >>> used as a mapping relationship between schemes and a >>> different relationship should be used. There could for >>> example be a set of skos mapping relationships, including >>> say broader_mapping. We don't see that this creating any >>> effective obstacle to semantic web applications but >>> rather assisting with the semantics. >>> >>> Returning to local vocabulary extensions, a fine point >>> is that in_scheme identifies the origin of each concept - >>> but does not identify the origin of each relationship. Is >>> there any easy way for a local vocabulary to indicate >>> that it is an extension of an earlier (larger) >>> vocabulary? It will tend to be the case in Digital >>> Library type applications that extensions are defined for >>> some of the major de facto standard vocabularies. >>> >>> Doug Tudhope & Ceri Binding >>> Hypermedia Research Unit >>> University of Glamorgan >>> >>> >>> >>> ________________________________ >>> >>> From: Antoine Isaac [mailto:aisaac@few.vu.nl] >>> Sent: Sun 29/07/2007 21:43 >>> To: Tudhope D S (AT) >>> Cc: public-esw-thes@w3.org; public-swd-wg@w3.org >>> Subject: Re: [SKOS] RE : Skos mapping issues >>> >>> >>> >>> Hi Doug, >>> >>> >>>> I tend to agree with Javier that it is important to be >>>> able to >>>> distinguish inter-thesaurus mappings from the standard >>>> intra thesaurus >>>> relationships. It's not clear to me that even the >>>> 'broader/narrower >>>> mappings' necessarily carry the same semantics, although >>>> there are >>>> some similarities. >>>> - As I see it, mappings usually carry a higher degree of >>>> uncertainty >>>> (and a lower confidence in any query expansion >>>> operations). >>>> >>> You might be right, even though in some cases, for query >>> expansion, I >>> would rely more on a mapping (especially for >>> equivalence) between >>> concepts from different thesauri than on an >>> inter-thesaurus BT... >>> >>> >>>> - Another point is that dissolving boundaries between >>>> specific >>>> thesauri (and similar concept schemes) would be counter >>>> productive. >>>> They are created as a discrete entities, intended to be >>>> internally >>>> consistent for information retrieval purposes in a >>>> domain, although >>>> perhaps taking a particular view. So, while you may make >>>> additional >>>> mappings of different kinds between thesauri, its >>>> important to retain >>>> the integrity of concepts/relations belonging to the >>>> same scheme. >>>> >>> I understand your point, but I really don't like this. >>> To having >>> skos:broader allowed between different concept schemes >>> is an easy way to >>> create local vocabulary extensions, which will improve >>> vocabulary >>> re-use, and hence bring more added value to the existing >>> ones. >>> If we are to provide a format to port controlled >>> vocabularies on the >>> semantic web then I would like not to prevent people in >>> the future to >>> use these vocabularies in a semantic-web way! >>> >>> Of course you could argue that this kind of link could >>> be represented by >>> a property different from skos:broader. Do you think >>> that the *semantic* >>> value (so, apart from e.g. consideration on editorial >>> control) of a BT >>> 'extension' link would be really different from a BT >>> inside a vocabulary? >>> >>> Antoine >>> >>> PS: allowing for skos:broader between different concept >>> schemes and >>> disconnecting the problem of the 'semantic value' of >>> skos broader from >>> the one of concept scheme containement [1] are actually >>> the reasons why >>> in other discussions I defend skos:inScheme. This >>> property seems to me a >>> less constraining (and more explicit) option for >>> representing provenance >>> and providing for some editorial control, even if it is >>> not perfect... >>> >>> [1] http://www.w3.org/2006/07/SWD/track/issues/36 >>> >>> >>>> Doug >>>> >>>> >>>> ------------------------------------------------------------ >>>> >> ------------ >> >>>> *From:* public-esw-thes-request@w3.org on behalf of >>>> Antoine Isaac >>>> *Sent:* Mon 23/07/2007 08:10 >>>> *To:* jlacasta@unizar.es; public-esw-thes@w3.org >>>> *Cc:* public-swd-wg@w3.org >>>> *Subject:* [SKOS] RE : Skos mapping issues >>>> >>>> [Sorry I skept the subject in previous posting] >>>> >>>> Hi Javier, >>>> >>>>> >>>>> Hi All, >>>>> >>>>> I am interested in the mapping of thesauri, so I have >>>>> >>>> been reviewing the >>>> >>>>> documentation available in the SKOS-Project. It seems >>>>> >>>> that there is >>>> three main >>>> >>>>> documents related with SKOS mapping in SKOS project >>>>> >>>> [1,2,3]. >>>> >>>> Oops now I've realized that it was not so smart of me to >>>> release 3, >>>> because I have missed 2. And there are indeed some >>>> similarities >>>> between the two, which is normal since I intended to >>>> make an account >>>> of a SWD discussion in which Alistair played an >>>> important role. Some >>>> synchronization should be done, so your discussion is >>>> useful (and my >>>> main intent behind [3] was also to revive this >>>> discussion :-) >>>> >>>> >>>>> Each one present a quite different approach to mapping >>>>> >>>> representation. The last >>>> >>>>> two documents it seems that try to simplify the skos >>>>> >>>> mapping vocabulary. >>>> >>>>> They map the partial and inexact equivalence >>>>> >>>> relationships to other >>>> existent >>>> >>>>> relations in SKOS core. The partial relationship is >>>>> >>>> mapped to >>>> skos:broader and >>>> >>>>> skos:narrower and the inexact is mapped or to >>>>> >>>> skos:related or to a new >>>> >>>>> skos:overlappingConcept. >>>>> >>>>> I agree that the semantic of the partial equivalence >>>>> >>>> relationship is >>>> equivalent >>>> >>>>> to the broader and narrower relationship. However, I >>>>> >>>> think that the >>>> use of the >>>> >>>>> same property would difficult the identification of >>>>> >>>> the mappings >>>> respect to the >>>> >>>>> basic ones. >>>>> >>>> This is the crucial problem. The semantics are the same, >>>> so we should >>>> make them a same property. >>>> Ideally the identification problem is distinct (in our >>>> working group >>>> we recorded it as [5]), so it should not intefere. >>>> But of course in practice [5] is very difficult to solve >>>> in RDF, so in >>>> the end we might have to consider more than the >>>> semantics to define a >>>> property. >>>> >>>> >>>>> I think that at least the namespaces should be changed >>>>> >>>> (e.g: >>>> >>>>> skosm.broader). This properties can be an >>>>> >>>> specialization >>>> >>>>> of the basic ones. This would facilitate the >>>>> >>>> separation of the >>>> mappings to the >>>> >>>>> core structure of each thesauri. >>>>> >>>> Problem is that specializing skos:broader might collide >>>> with the need >>>> to identify a skos:broader statement in a scheme in a >>>> way similar to >>>> the one you want to identify a mapping. Some people (cf >>>> [6]) would >>>> like skos:broader statements to hold only between >>>> concepts from one >>>> scheme. >>>> I'm not a strong believer of this, but I certainly think >>>> that if we >>>> want to record mapping identification by creating a >>>> special property >>>> we should not make identification of intra-thesaurus >>>> links even more >>>> difficult than what it is now. >>>> >>>> >>>>> I do not agree with the use of skos:related as inexact >>>>> >>>> equivalence >>>> exposed in >>>> >>>>> [2]. I think they are different. An inexact >>>>> >>>> equivalence indicates >>>> >>>>> that two concepts share some meaning and that not >>>>> >>>> always happen with >>>> the more >>>> >>>>> general skos:related relationship. >>>>> A inexact equivalence relationship can be seen as an >>>>> >>>> specialization of >>>> >>>>> skos:related given that indicate a relationship >>>>> between the concepts but not in the other way. >>>>> >>>> +1 >>>> >>>> >>>>> Respect to the compositions of mappings through "and", >>>>> >>>> "or" and "not" >>>> >>>>> relationships I think that to be able to create >>>>> >>>> complex compositions as >>>> >>>>> (A and B and (C or (D and E))), it would be needed a >>>>> >>>> specialization >>>> of skos >>>> >>>>> concept (called for example conceptCollection) to >>>>> >>>> group all the composed >>>> >>>>> concepts and the type of composition. >>>>> >>>>> I see that there are some similarities in the "and" >>>>> >>>> relationship >>>> respect to the >>>> >>>>> pre-coordination of labels in a thesaurus, and also >>>>> >> respect to the >> >>>>> composition in USE relationship to >>>>> >>>> refer from a >>>> complex label to >>>> >>>>> two simpler ones. However, I think they are >>>>> some semantic differences between the "and" and the >>>>> >>>> coordination >>>> making them not >>>> >>>>> completely interchangeable. >>>>> >>>> This was the point in [3] to treat this "and" problem in >>>> the context >>>> of a different coordination problem which is on the SWD >>>> agenda [4] >>>> Your point about "and" and pre-coordination is valid. >>>> There are case >>>> of complex mappings with conjunctions that could well >>>> correspond to >>>> post-coordination cases, and [4] is too narrow for this. >>>> So we should re-introduce post-coordination in the loop >>>> by means of >>>> some specific "and". Something which semantics should be >>>> roughly >>>> if x match (y andpostcoord z) then (if doc skos:subject >>>> x then doc >>>> skos:subject y and doc skos:subject z ) >>>> >>>> I think it is still a good idea to separate it from >>>> pre-coordination: >>>> in my current view (and I learned a lot reading the wise >>>> posts of this >>>> list, and could continue learning) >>>> A mapping to a pre-coordination is a mapping to a >>>> single, even if >>>> complex, subject: the semantics would not imply infering >>>> new >>>> skos:subject triples. In this case the problem is >>>> delegated to [4] >>>> A mapping to post-coordination would involve several >>>> subjects, as >>>> mentioned in the previous rule >>>> Would such an approach alleviate your concerns? >>>> >>>> Best, >>>> >>>> Antoine >>>> >>>> >>>>> [1] http://www.w3.org/2004/02/skos/mapping/spec/ >>>>> [2] >>>>> >>>> http://isegserv.itd.rl.ac.uk/public/skos/press/dc2006/mapping.html >>>> >>>>> [3] >>>>> >> http://www.w3.org/2006/07/SWD/wiki/SkosDesign/> >> > ConceptualMapping/Propo > >>>> salOne >>>> [4] http://www.w3.org/2006/07/SWD/track/issues/40 >>>> [5] http://www.w3.org/2006/07/SWD/track/issues/47 >>>> [6] http://www.w3.org/2006/07/SWD/track/issues/36 >>>> >>>> >>> >>> >> >> >> >> >> > > > > > -- *Bernard Vatant *Knowledge Engineering ---------------------------------------------------- *Mondeca** *3, cité Nollez 75018 Paris France Web: www.mondeca.com <http://www.mondeca.com> ---------------------------------------------------- Tel: +33 (0) 871 488 459 Mail: bernard.vatant@mondeca.com <mailto:bernard.vatant@mondeca.com> Blog: Leçons de Choses <http://mondeca.wordpress.com/>
Received on Friday, 3 August 2007 10:17:16 UTC