Re: Last Call comments on RDFa Core (Issue-86)

On Dec 13, 2010, at 13:36 , Harry Halpin wrote:

>> On Mon, 2010-12-13 at 11:19 +0000, Harry Halpin wrote:
>>> To my knowledge, I have not seen a single halfway convincing usecase
>>> where there is a reason why you would want to 'mention' a URI, i.e.
>>> refer to it as a literal or xsd string.
>> 
>> Given the following:
>> 
>> ###
>> @prefix con: <http://www.w3.org/2000/10/swap/pim/contact#> .
>> @prefix owl: <http://www.w3.org/2002/07/owl#> .
>> 
>> <http://www.w3.org/People/Berners-Lee/card#i>
>> 	con:preferredURI <http://www.w3.org/People/Berners-Lee/card#i> ;
>> 	owl:sameAs <http://identi.ca/user/45563> .
>> ###
>> 
>> An OWL-capable processor can make the following conclusion:
>> 
>> ###
>> @prefix con: <http://www.w3.org/2000/10/swap/pim/contact#> .
>> 
>> <http://www.w3.org/People/Berners-Lee/card#i>
>> 	con:preferredURI <http://identi.ca/user/45563> .
>> ###
>> 
>> However, given:
>> 
>> ###
>> @prefix con: <http://www.w3.org/2000/10/swap/pim/contact#> .
>> @prefix owl: <http://www.w3.org/2002/07/owl#> .
>> 
>> <http://www.w3.org/People/Berners-Lee/card#i>
>> 	con:preferredURI "http://www.w3.org/People/Berners-Lee/card#i" ;
>> 	owl:sameAs <http://identi.ca/user/45563> .
>> ###
>> 
>> It will not come to a mistaken conclusion about what timbl's preferred
>> URI for himself is.
> 
> 
> Yes, TimBL also gave me that example. However, that example is not
> plausible, much less convicing.
> 
> It seems to be the fault of a misuse of sameas and the attendant wrong OWL
> conclusions, again, of which I have done an analysis of, feel free to read
> [1].  The right answer is probably not to use sameAs or OWL at all, but
> use something like a SIOC term for accountOf.  Right now we are doing a
> study of how most things that are inferred via using OWL over sameas are
> wrong, our guess so far is more than half of the inferences that use
> sameas are incorrect. Given that sameAs usage is often broken, usecases
> involving sameAs are IMHO red herrings.
> 
> So, try again. Not convincing a reason for essentially doubly the number
> of prefix terms in RDFa and making widespread vocabularies like OGP not
> interpreted as they were intended.
> 
> [1] http://iswc2010.semanticweb.org/pdf/261.pdf
> 
>> 
>> --
>> Toby A Inkster
>> <mailto:mail@tobyinkster.co.uk>
>> <http://tobyinkster.co.uk>
>> 
>> 
> 
> 


----
Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
PGP Key: http://www.ivan-herman.net/pgpkey.html
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