- From: Ivan Herman <ivan@w3.org>
- Date: Fri, 17 Jul 2009 10:03:55 +0200
- To: Ben Adida <ben@adida.net>
- CC: RDFa <public-rdf-in-xhtml-tf@w3.org>
- Message-ID: <4A60306B.4040800@w3.org>
Just like Michael and Toby, I do have my issues... Ben Adida wrote: [snip] > Markup in the page: > > <div about="#me" prefix="http://myvocab.org/#"> > My name is <span property="name">Ben Adida</span> > > and my email is > > <a rel="email" href="mailto:ben@adida.net"> > ben@adida.net > </a> > </div> > > > Vocabulary Definition at http://ben.adida.net/vocab, using RDFa: > > <div about="#name" typeof="rdf:Property"> > <h4 property="rdfs:label">name</h4>, > which corresponds to > <a rel="owl:sameAs" > href="http://xmlns.com/foaf/0.1/name"> > foaf:name > </a>. > </div> > > <div about="#email" typeof="rdf:Property"> > <h4 property="rdfs:label">email</h4>, > which corresponds to > <a rel="owl:sameAs" > href="http://rdfs.org/sioc/ns#email"> > sioc:email > </a>. > </div> > I presume that you messed up the example and you wanted to use 'http://myvocab.org' in the second part (instead of 'http://ben.adida.net/vocab') right? If not, then I too, like Michael, have problems understanding how you get there... However, I must admit that I am not 100% sure what is being proposed in practice. The issue is what the requirement is on an RDFa processor. Indeed, I can look at it with two different ways: 1. A comformant RDFa processor is required to dereference the URI http://myvocab.org/#, extract the RDF data there, make the identifications through, say, sameAs, and provide the output in terms of the, in this example, SIOC triples. As far as I can see, this is NOT what you propose, but I am just trying to make it explicit in case I misunderstand... However if that _is_ what you propose, I do feel uneasy. It does create a significant extra load on RDFa processors, which are meant to be relatively easy to implement and deploy. This proposal requires various RDF parsing modules (we cannot _require_ that the vocabulary must be described in RDFa, can we?), at least some sort of an OWL 2 RL level inference on RDF/OWL graphs, corresponding queries, built into it... Of course, all that is doable, but that is way too much to ask for an easy deployment of RDFa (which is a major selling point...) 2. But, if that is _not_ the case, ie, RDFa processors are not required to do all that, then I do not understand what the proposal really brings that is not, in theory, part of the RDF/OWL infrastructure as of today. If I take your example above, using simply @xmlns (to stay with the current standard) I would produce with an RDFa processor <#me> <http://myvocab.org/#name> "Ben Adida" . <#me> <http://myvocab.org/#email> <mailto:ben@adida.net> . And if I am a vocabulary maintainer, I would put an RDF file in whatever syntax I wish (RDFa or not) to http://myvocab.org/# which says <http://myvocab.org/#email> a rdf:Property; owl:equivalentProperty <http://rdfs.org/sioc/ns#email> . and then a full-blown, OWL aware processor would do the right thing by dereferencing <http://myvocab.org/#email>. That is, in theory, what happens _today_ on an RDF/OWL environment. I fail to see what is new in this case... 3. As a side issue, I fully agree with Toby. _If_ we use OWL terms, we should be careful what we require (although users will get it wrong...). owl:equivalentProperty is the right thing to do even in OWL (2) Full, for example and not sameAs, stuff like that... So: I am not sure I fully grasp the proposal...:-( Cheers Ivan -- 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 FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Friday, 17 July 2009 08:04:30 UTC