Re: RDF Recommendation Set comments (re agenda for 6th April)

On Apr 7, 2011, at 11:32 AM, Antoine Zimmermann wrote:

> Le 07/04/2011 17:58, William Waites a écrit :
>> * [2011-04-07 17:40:37 +0200] Antoine Zimmermann<antoine.zimmermann@insa-lyon.fr>  écrit:
>> 
>> ] :x owl:sameAs "abc" .
>> ] :x owl:sameAs "xyz" .
>> 
>> So this is true, but in the case of catching modelling errors it
>> is unlikely, I suspect, to crop up. Much more likely is to have
>> a URI or bnode object where this wouldn't be a contradiction...
> 
> Honestly, I believe this one actually can be inferred in non-trivial ways on the currently deployed Web of Data, with only RDFS and owl:sameAs. Of course, this is probably not going to be written as is by someone who really believes that the string "abc" is equal to the string "xyz".
> 
>> 
>> ] rdf:type owl:sameAs owl:sameAs .
>> 
>> Now that's a funny pathology, but I also suspect it would be
>> uncommon. I'm more interesting in finding errors in data that is
>> "almost right", not constructing pathological cases.
> 
> You can hardly implement a reasoner where you have to manually add special treatment of all the "uncommon" cases that lead to contradictions. Usually, contradictions come from trivial and absurd errors, such as saying that Tim Berners-Lee is a document

While nonsensical, I doubt it that is a logical contradiction to anything. Most errors are not logically inconsistent. I think that relying on consistency checking to find errors is simply a mistake/poor design. 

Pat Hayes

> or that the resource identified by http://www.w3.org/ is equivalent to the character string "http://www.w3.org/". These things are not uncommon at all in real data.
> 
> 
>> 
>> Cheers,
>> -w
> 
> 
> -- 
> Antoine Zimmermann
> Researcher at:
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> Database Group
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> Tel: +33(0)4 72 43 61 74 - Fax: +33(0)4 72 43 87 13
> Lecturer at:
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> antoine.zimmermann@insa-lyon.fr
> http://zimmer.aprilfoolsreview.com/
> 
> 

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Received on Thursday, 7 April 2011 16:41:22 UTC