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Re: [Dbpedia-discussion] Using DBpedia resources as skos:Concepts?

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Thu, 05 Nov 2009 17:42:44 -0500
Message-ID: <4AF354E4.4070202@openlinksw.com>
To: Antoine Isaac <aisaac@few.vu.nl>
CC: Neubert Joachim <J.Neubert@zbw.eu>, Simon Reinhardt <simon.reinhardt@koeln.de>, SKOS <public-esw-thes@w3.org>, Pat Hayes <phayes@ihmc.us>, dbpedia-discussion@lists.sourceforge.net
Antoine Isaac wrote:
> Kingsley,
>>>>> Sorry for causing some misunderstanding: My point was not that you 
>>>>> SHOULD use skos:Concept. What I rather wanted to say is that it 
>>>>> does no harm and that it's already in use for named entites.  This 
>>>>> point arises from the suggestion to use 
>>>>> skos:exactMatch/closeMatch. These properties are 
>>>>> sub-sub-properties of skos:semanticRelation, which entails that 
>>>>> subject and object of these properties are instances of 
>>>>> skos:Concept (since skos:Concept are domain and range for 
>>>>> skos:semanticRelation).
>>>>> The great advantage of skos:exactMatch/closeMatch (over 
>>>>> owl:sameAs) is that their semantic doesn't smush the resources 
>>>>> with all their properties (like the administrative properties you 
>>>>> mentioned).
>>>> Joachim,
>>>> What do you mean by "smush" are you referring to the union 
>>>> expansion that results from combing data from all the data sources 
>>>> in the owl:sameAs relation? I pose my question with the 
>>>> skos:exactMatch description page URL [1] for context. I see 
>>>> Transitivity and Symmetry, which are factors re. decision making by 
>>>> reasoners re: union expansion based on participants in the 
>>>> relation. Note, by "union expansion" I mean the union of all data 
>>>> associated with the data items in the relation.
>>>> Primarily, I just want clarification about "smushing",  relative to 
>>>> the property definition exposed by the skos:exactMatch URI,  more 
>>>> than anything else. Thus, far I've simply assumed that 
>>>> skos:exactMatch and owl:sameAs have similar implementation 
>>>> mechanics re. union expansion, 
>>> Just to clarify it, in case the mails that came after have not done 
>>> it: using skos:exactMatch should *not* lead to attributing to the 
>>> two resouces that it relates the union of all data that is attached 
>>> to them.
>>> I don't understand why transitivity and symmetry alone would allow a 
>>> reasoner to infer such "smushing/union expansion". Let's consider a 
>>> ex:connectedByARoad property. I can perfectly make it transitive and 
>>> symmetric, and yet all the towns that this property relates are not 
>>> one and the same.
>> Sure, but the relation you use is neither "owl:sameAs" nor 
>> "skos:exactMatch". I think the subtle item here is that the property 
>> labels do actually matter. ex:connectedByARoad in no way conveys 
>> co-reference. 
> Er, yes. My comment was havily influenced by your "which are factors 
> re. decision making by reasoners". Labels are not such a factor, so I 
> inferred you were only basing your claim on the formal semantic axioms.
>> BTW - your analogy is basically similar to a Transitivity example I 
>> put out re. SKOS and DBpedia a few weeks ago [1] :-)
> :-)
>> I think your other response re. Ms. Obama goes back to the Subject 
>> Matter/Heading delineation which I believe is the overarching focal 
>> point of of SKOS (classification by phenotype so to speak). Its about 
>> concept schemes and the hierarchies that may exist within and across 
>> schemes in different data spaces. Whereas, with "owl:sameAs" we are 
>> dealing with similar issues, but the orientation feeds of a genotype, 
>> so to speak.
> As long as you're ok with the fact that there can be concepts/subject 
> matters that are corresponding to persons (even though they would not 
> be persons themselves), I'm ok...


> Antoine
> [snip]
>>>>> ------------------------------------------------------------------------ 
>>>>> *Von:* Simon Reinhardt [mailto:simon.reinhardt@koeln.de]
>>>>> *Gesendet:* Do 05.11.2009 17:35
>>>>> *An:* Neubert Joachim
>>>>> *Cc:* Richard Cyganiak; dbpedia-discussion@lists.sourceforge.net; 
>>>>> SKOS; Pat Hayes
>>>>> *Betreff:* Re: AW: [Dbpedia-discussion] Using DBpedia resources as 
>>>>> skos:Concepts?
>>>>> Hi
>>>>> Neubert Joachim wrote:
>>>>> > In my eyes, it's completely ok to use skos:exactMatch or 
>>>>> skos:closeMatch
>>>>> > in a situation like this (I did it myself for the STW Thesaurus for
>>>>> > Economics mapping to dbpedia).
>>>>> > > Thesauri and classifications are not restricted to abstract 
>>>>> concepts.
>>>>> > Some thesauri deal explicitly with individual things, e.g. the 
>>>>> widely
>>>>> > used Getty "Thesaurus of Geographic Names" or "Union List of Artist
>>>>> > Names". Other thesauri (like STW) have sections (or facets, as 
>>>>> Leonard
>>>>> > put it) on geografic names along with others containing "pure" 
>>>>> concepts.
>>>>> > SKOS, as I understand it, is intended to cover all this and to 
>>>>> be used
>>>>> > beyond strict class hierarchies or class/individual dichotomies.
>>>>> While I agree that using real-world entities for classification is 
>>>>> ok I don't think this means you have to declare them to be 
>>>>> (skos:)concepts. The "has subject" relationship in FRBR [1] for 
>>>>> example can link a work to a concept but also to places, people, 
>>>>> events, other works, etc. So in this case you can use real-world 
>>>>> entities to classify the work (to state what its subjects are) but 
>>>>> that doesn't mean you declare all those entities to be conceptual.
>>>>> So in my eyes there's still value in keeping (skos:)concepts and 
>>>>> other things apart. Concepts to me are closer to classes than to 
>>>>> individuals. And as Dan pointed out concepts have administrative 
>>>>> data attached - they get created and changed etc. so they're 
>>>>> basically units of organisation.
>>>>> I'd therefore prefer using the UMBEL terms or something else for 
>>>>> aligning real-world entities and concepts.
>>>>> > By the way, some of the SKOS properties (especially the
>>>>> > prefLabel/altLabel/hiddenLabel semantics) can be useful in a 
>>>>> broad range
>>>>> > of applications. Eg. dbpedia itself could be used as a great 
>>>>> source for
>>>>> > synonym candidates by mapping the resources to skos:Concept and the
>>>>> > labels for dbpedia:redirect resources to skos:altLabel.
>>>>> Yup, it has a lot of useful annotation terms. They are all 
>>>>> declared to be annotation properties and deliberately don't have 
>>>>> skos:Concept in their domain. So you can use them on anything 
>>>>> which is great!
>>>>> Regards,
>>>>>   Simon
>>>>> [1] http://archive.ifla.org/VII/s13/frbr/frbr_current5.htm#5.2 - 
>>>>> scroll down to "5.2.3 Subject Relationships"
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>>>>> _______________________________________________
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>>>>> Dbpedia-discussion@lists.sourceforge.net
>>>>> https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion



Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Thursday, 5 November 2009 22:43:23 UTC

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