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

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:
http://downloads.dbpedia.org/preview.php?file=3.0_sl_en_sl_links_cyc_en.nt.bz2

> [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  
blog.
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


_________________________________

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

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