Re: Draft Note for HTML WG

On Nov 14, 2011, at 14:25 , Dan Brickley wrote:

> On 14 November 2011 13:23, Ivan Herman <ivan@w3.org> wrote:
>>> ... while also collecting mappings to the other widely used RDF vocabs. If RDFa parsers did
>>> something useful with such mappings, that might help move things along too...
>> 
>> I am not sure what you mean. What would you think an RDFa parser may do?
> 
> I was thinking of the mechanism we discussed the other day. For
> example, if http://schema.org/Person has an annotation saying
> 'equivalentClass foaf:Person', then a post-processing option in a
> parsing tool could allow that annotation to be used to expand out some
> extra triples in the results. That said, I'm wary of something that
> could put unpredictable load on vocab publisher's servers...
> 

This is almost exactly the @vocab mechanism! Except that the minimal definition in RDFa does not rely (currently) on the owl vocabulary, only on the RDF(S) one. But if the schema.org vocabulary file has a subClass of foaf:Person, that will be used and any resource of type schema:person will also be a foaf:Person.

equivalent class is very strong. That is a form of hijacking; after all, that would also mean that each foaf:Person is also a schema.org person. Which may be a true statement, but as a general mechanism it is heavy and dangerous, a reason why the RDFa group did not adopt that. (Another reason is that the spec can now refer to a small subset of RDFS entailment, but then it would have to refer to a small subset of OWL RL, which is heavier...)

Ivan



> Dan


----
Ivan Herman, W3C Semantic Web Activity Lead
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FOAF: http://www.ivan-herman.net/foaf.rdf

Received on Monday, 14 November 2011 13:49:53 UTC