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Ranging Properties (was: Re: Musing on URI references vs. URI-s as string)

From: Knud Hinnerk Möller <knud.moeller@deri.org>
Date: Wed, 22 Sep 2010 12:22:11 +0200
Cc: Ivan Herman <ivan@w3.org>, W3C RDFa WG <public-rdfa-wg@w3.org>
Message-Id: <339E6D88-7B08-460A-AAC5-89BE4F779364@deri.org>
To: nathan@webr3.org

On 21 Sep 2010, at 23:26, Nathan wrote:

> ...
> Ranging properties:
> Forgive my newness on this one, but has any work/discussion previously gone in to setting the type of an object based on the range of the property, for instance the range of foaf:name is foaf:Document.

you mean foaf:homepage, right?

> Thus it should be pretty easy to determine that if somebody writes:
> <span property="foaf:homepage">http://www.w3.org</span>
> Then the triple produced should be
> :x foaf:homepage <http://www.w3.org>
> as this is the only valid triple possible.

As far as I know, this kind of processing - interpreting the rdfs:range of a property, or distinguishing that it was declared as an owl:ObjectProperty vs. an owl:DatatypeProperty - is happening at a higher level than just the syntactic parsing of an RDF serialisation. You would need some kind of RDFS or OWL reasoning in place (or a simple rule for cases like this). So, I'm not sure how people would react if we put something like this into RDFa Core. 

On the other hand, it could be interesting to include this into an RDFa parser, to make it more robust and lenient. It would be like Web browsers accepting invalid HTML and guessing what was probably meant by it. On the one hand this might help to improve the growth of RDFa, on the other hand it might lead to chaos. 


> Generally the aforementioned ranging approach is something which I'm unsure why we don't use more on the web of data (for both removing ambiguity wrt the type of objects, and for verifying graphs produced when parsing.
> Still, glad to see this niggling away with somebody else :)
> Best,
> Nathan

Knud Möller, PhD
+353 - 91 - 495086
Smile Group: http://smile.deri.ie
Digital Enterprise Research Institute
  National University of Ireland, Galway
Institiúid Taighde na Fiontraíochta Digití
  Ollscoil na hÉireann, Gaillimh
Received on Wednesday, 22 September 2010 10:28:07 UTC

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