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

From: Aldo Gangemi <aldo.gangemi@cnr.it>
Date: Thu, 15 May 2008 14:17:58 +0200
Cc: Aldo Gangemi <aldo.gangemi@cnr.it>, "Michael F Uschold" <uschold@gmail.com>, 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>, Frederick Giasson <fred@fgiasson.com>, Michael Bergman <mike@mkbergman.com>, Conor Shankey <cshankey@reinvent.com>, Kira Oujonkova <koujonkova@reinvent.com>
Message-Id: <E34FC7E1-5972-47EF-BA76-E7753F5E3D1F@cnr.it>
To: Richard Cyganiak <richard@cyganiak.de>

Hi Richard, sorry for any misquotation, I wanted to describe the  
issue, not to criticize
other opinions out of context. See comments below

Il giorno 15/mag/08, alle ore 12:20, Richard Cyganiak ha scritto:

> Aldo,
> Please keep your facts straight.
> On 14 May 2008, at 22:24, Aldo Gangemi wrote:
>> 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,
> I would like to point out that I haven't come across any instance  
> where this has been done or encouraged.

I have not said that, but that none has "discouraged"

>> or a city as from Cyc to a wikipedia article of that city (as done  
>> in DBpedia).
> DBpedia doesn't contain any owl:sameAs statements between Cyc  
> resources and Wikipedia articles.

See the extended datasets (http://wiki.dbpedia.org/Downloads) for  
"Links to Cyc" at:

> [snip]
>> 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?
> I feel misquoted. In the original discussion [1], I encouraged the  
> use of owl:sameAs between three different definitions (Geonames,  
> GEMET and DBpedia) of the concept of a “canal”. I did *not* advocate  
> to gloss over the difference between a thing and a document about  
> that thing, as you imply by your examples above. To the contrary, I  
> have insisted on this difference many times, e.g. in [2].

That's ok. I used an indirect quotation of yours from Bernard Vatant's  
Talking of content, on the sameness of Geonames and DBpedia articles I  
have anyway a different intuition:
Geonames refer to geographical locations, DBpedia entries to articles,  
which on their turn can refer to geographic locations

> At the end of the day, we have to keep in mind that we are talking  
> about the Web. Statements will be subjective, inconsistent and  
> wrong. This also applies to owl:sameAs statements. They are claims,  
> not facts. Deal with it.

Agreed. I do not want to be picky about that: SW is Web, and errors  
are life.
Just there is no need to use owl:sameAs in many cases, and at least in  
LOD large projects, this can be avoided easily.

Thanks for clarifying


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


icq# 108370336

skype aldogangemi
Received on Thursday, 15 May 2008 12:18:23 UTC

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