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Re: Managing Co-reference (Was: A Semantic Elephant?)

From: Aldo Gangemi <aldo.gangemi@cnr.it>
Date: Thu, 15 May 2008 14:19:41 +0200
Cc: Aldo Gangemi <aldo.gangemi@cnr.it>, "Tim Berners-Lee" <timbl@w3.org>, "Sören Auer" <auer@informatik.uni-leipzig.de>, "Semantic Web Interest Group" <semantic-web@w3.org>, "Chris Bizer" <chris@bizer.de>, "Frank van Harmelen" <Frank.van.Harmelen@cs.vu.nl>, "Kingsley Idehen" <kidehen@openlinksw.com>, "Fabian M. Suchanek" <f.m.suchanek@gmail.com>, "Tim Berners-Lee" <timbl@csail.mit.edu>, "Jim Hendler" <hendler@cs.rpi.edu>, "Mark Greaves" <markg@vulcan.com>, georgi.kobilarov@gmx.de, "Jens Lehmann" <lehmann@informatik.uni-leipzig.de>, "Richard Cyganiak" <richard@cyganiak.de>, "Frederick Giasson" <fred@fgiasson.com>, "Michael Bergman" <mike@mkbergman.com>, "Conor Shankey" <cshankey@reinvent.com>, "Kira Oujonkova" <koujonkova@reinvent.com>, a.o.jaffri@ecs.soton.ac.uk, hg@ecs.soton.ac.uk, icm@ecs.soton.ac.uk
Message-Id: <501A837A-3BFA-4BB1-9FE2-1C056E480690@cnr.it>
To: Michael F Uschold <uschold@gmail.com>
Thanks Michael.
BTW, I was not suggesting rdfs:seeAlso or skos:related as a good  
practice, but as a less harmful one :)
A

Il giorno 15/mag/08, alle ore 01:25, Michael F Uschold ha scritto:

> Aldo notes the problems with using owl:sameAs to mean similarity.  
> Such uses are often incorrect, and Aldo suggests using something  
> like rdfs:seeAlso, skos:related, instead. These relations are too  
> weak, unfortunately.
>
> There is an interesting proposal for managing URI snyonyms that  
> attempts to have a middle ground, weaker than owl:sameAs, but much  
> stronger than rdfs:seeAlso or skos:related.   They suggest an  
> infrastructural approach [apparently] outside the logic for managing  
> URI synonyms. It is a quite clever approach, but still has some  
> challenges.  Here are portions of a note I just sent the authors of  
> a paper, which relates to this question.
>
> Afraz, Hugh and Ian:
>
> I just read your workshop paper:
> Managing URI Synonymity to Enable Consistent Reference on the  
> Semantic Web
>
> I wholeheartedly agree that owl:SameAs is too strong in many cases.  
> A weaker relation is needed. However, you don't offer  weaker  
> relation and give it semantics. Instead, you do a kind of sleight of  
> hand and remove it from the logic.  Without  a semantics, what is a  
> system developer to do with the fact that two URIs are in the same  
> bundle?  What are the inferential impliciations?
>
> Example: IMHO it is a bad idea to say that Spain the political  
> entity is the same as Spain the geopolicial region. This ontological  
> distinction has been clear documented in DOLCE, for example. They  
> are different, and should have different URIs.  Conflating them will  
> cause problems.  Of course, making this and many other ontologically  
> 'sound' distinctions can cause its own problems, by adding  
> complexity -- a tradeoff. Without any semantics of inCRS_Bundle,  
> there is no way to tell if it is semantically correct.
> Do you have any idea of the scalability of this approach?
> Michael
>
>
>
> On Wed, May 14, 2008 at 2:24 PM, Aldo Gangemi <aldo.gangemi@cnr.it>  
> wrote:
>        • Problem 2) even if you can find the links, prolific use of  
> owl:sameAs will create computational problems.
>
>
>
> Michael,
>
> there is an item related to Problem 2), already discussed on LOD and  
> elsewhere last year, i.e. the use of
> owl:sameAs, which is a formal relation of identity, to denote  
> generic "similarity", or even "relatedness"
> between two entities.
>
> owl:sameAs is great to co-reference persons, places, etc. It is  
> buggy when used to relate e.g. foaf:Person
> instances to persons' homepages, or a city as from Cyc to a  
> wikipedia article of that city (as done in DBpedia).
>
> In previous discussions, besides some weak good practices [1], I  
> found no attempt to discourage its use for similarity.
> This use is not needed. We can use e.g. rdfs:seeAlso, skos:related,  
> or any other local relation instead.
>
> It is reasonable, as Richard Cyganiak wrote at the time, that we  
> have to work around the quirks [2],
> nonetheless, if there is no real need, why should we work around the  
> quirks caused by a pointless identity
> assumption?
>
> Notice that ignoring owl:sameAs is not a good solution. We need some  
> trade-off between simplicity
> and formality. A basic similarity relation is perfect, and then  
> those triples can be worked out automatically,
> by means of appropriate metamodels, e.g. as proposed in [3].
>
> Aldo
>
> [1] Bernard Vatant suggested some good practice of mutual linking:
> http://universimmedia.blogspot.com/2007/07/using-owlsameas-in-linked-data.html
>
> [2] Cyganiak quote:
> People who want to re-use your data will learn to work around its  
> quirks and idiosyncrasies.
> Dealing with the quirks is a part of re-using data, it always was,  
> and it always will be.
>
>
> [3] http://www.ibiblio.org/hhalpin/irw2006/vpresutti.pdf from IRW  
> workshop: http://www.ibiblio.org/hhalpin/irw2006/
>
>
> _________________________________
>
> Aldo Gangemi
>
> Senior Researcher
> Laboratory for Applied Ontology
> Institute for Cognitive Sciences and Technology
> National Research Council (ISTC-CNR)
> Via Nomentana 56, 00161, Roma, Italy
> Tel: +390644161535
> Fax: +390644161513
> aldo.gangemi@cnr.it
>
> http://www.loa-cnr.it/gangemi.html
>
> icq# 108370336
>
> skype aldogangemi
>
>
>


_________________________________

Aldo Gangemi

Senior Researcher
Laboratory for Applied Ontology
Institute for Cognitive Sciences and Technology
National Research Council (ISTC-CNR)
Via Nomentana 56, 00161, Roma, Italy
Tel: +390644161535
Fax: +390644161513
aldo.gangemi@cnr.it

http://www.loa-cnr.it/gangemi.html

icq# 108370336

skype aldogangemi
Received on Thursday, 15 May 2008 12:20:11 GMT

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