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

From: John Graybeal <jbgraybeal@mindspring.com>
Date: Thu, 5 Nov 2009 11:25:01 -0800
Cc: Neubert Joachim <J.Neubert@zbw.eu>, Simon Reinhardt <simon.reinhardt@koeln.de>, SKOS <public-esw-thes@w3.org>, Hayes Pat <phayes@ihmc.us>
Message-Id: <7F867C5B-AFA5-47E0-9DC3-67DE8A79AD24@mindspring.com>
To: Kingsley Idehen <kidehen@openlinksw.com>
> Thus, far I've simply assumed that skos:exactMatch and owl:sameAs  
> have similar implementation mechanics re. union expansion, but their  
> use targets vary i.e. skos:exactMatch works better for Concept  
> Schemes (where the world view assumes Named Entities e.g., "People"  
> aren't Concepts) while owl:sameAs works better for Named Entities  
> (people, places, and other typical real more things, so to speak).

I'm sorry, but my understanding of the semantics of owl:sameAs seems  
to be different than is being implied here -- can someone address this  
explicitly?

I have always understood owl:sameAs to link (very tightly!) one on- 
line resource to another.  For example, I could say that my URL is  
referring to exactly the same concept as someone else's URN.  So  
anything said about one concept now applies to the other, if sameAs is  
used. Maybe what's confusing me in this exchange is that I could  
imagine several different URLs that refer to an individual person (for  
example), but present that individual in different contexts, and the  
things they say are relative to the context.  Even though the  
individuals at http://mywork.com/staff/joebob, http://joebobfamily.name/joebob 
, and foaf:person=joebob are the same person, that does not mean that  
owl:sameAs is an acceptable linkage of those 3 resources.  Which  
suggests "owl:sameAs works better for Named Entitites" is not a good  
practice to follow, doesn't it?

John



On Nov 5, 2009, at 1029, Kingsley Idehen wrote:

> Neubert Joachim wrote:
>> Hi Simon,
>> 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, but their use targets vary i.e. skos:exactMatch  
> works better for Concept Schemes (where the world view assumes Named  
> Entities e.g., "People" aren't Concepts) while owl:sameAs works  
> better for Named Entities (people, places, and other typical real  
> more things, so to speak).
>
>
> Links:
>
> 1. http://linkeddata.uriburner.com/about/html/http/www.w3.org/2004/02/skos/core%01exactMatch
>
> Kingsley
>> [SNIP]
>> ..
>> Cheers, Joachim
>>
>> ------------------------------------------------------------------------
>> *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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>>
>
>
> -- 
>
>
> Regards,
>
> Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
> President & CEO OpenLink Software     Web: http://www.openlinksw.com
>
>
>
>
>


--------------
I have my new work email address: jgraybeal@ucsd.edu
--------------

John Graybeal   <mailto:jgraybeal@ucsd.edu>
phone: 858-534-2162
Development Manager
Ocean Observatories Initiative Cyberinfrastructure Project: http://ci.oceanobservatories.org
Marine Metadata Interoperability Project: http://marinemetadata.org
Received on Friday, 6 November 2009 01:49:09 GMT

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