- From: Joakim Söderberg <joakim.soderberg@ericsson.com>
- Date: Wed, 16 Mar 2011 04:33:11 +0100
- To: Pierre-Antoine Champin <pierre-antoine.champin@liris.cnrs.fr>, "public-media-annotation@w3.org" <public-media-annotation@w3.org>
Dear Pierre-Antoine, I can confirm that reading directly at: http://liris.cnrs.fr/~pchampin/research/mawg/id3/ Works! I find your examples [1] very useful. However I'm afraid I don't follow what you mean that the RDF produced (from complete.mp3) should *entail* the graph complete.ttl graph? And regarding assigning URIs to id3v2: namespace, I guess you mean: id3v2:TCOM rdfs:subPropertyOf :hasContributor id3v2:TEXT rdfs:subPropertyOf :hasContributor etc. But the example files don't recommend any particular bindings to sub-properties, but only demonstrates one way of how it could be done, hence proving that it works, and we have already stated to the user that some semantics may be lost. Or? [1] http://www.w3.org/2008/WebVideo/Annotations/wiki/Format_mapping_review -----Original Message----- From: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] On Behalf Of Pierre-Antoine Champin Sent: den 9 mars 2011 16:41 To: public-media-annotation@w3.org Subject: mapping, RDF and test-cases Hi all, [Summary: I explain some issues about RDF-based test-cases, and I propose a solution] I said in a previous telecon that I had some concern about making test-cases for the RDF mapping. Let me illustrate my initial concern: when mapping the metadata from http://champin.net/research/mawg/id3/complete.mp3 I would like the output to look like this [2] http://champin.net/research/mawg/id3/ext-complete.ttl However, I can not provide that Turtle file as a reference for test cases, because of a number of problems: 1/ as suggested by the RDF mapping [1], I minted a number of URIs (in the id3v2: namespace) for *subproperties* of the original ma: properties, whenever ID3 had a more precise semantics. For example, TEXT provides the name of the *lyricist*, so a sub-property of ma:hasContributor should be used. However, we do not want to prescribe the URIs of such sub-properties, so they should not appear in the test-cases. 2/ although ID3 does not use URIs for languages, I was able to generate a valid URI from the ISO-639 code [2]. While this is a useful mechanism, it can not be prescribed either, as we do not want to sponsor a particular URI-scheme for languages. An obvious solution would be to strip the RDF output the bone, stricly sticking to what is *required* from the MA ontology. This gives something like: http://champin.net/research/mawg/id3/complete.ttl which is correct, but loses a lot of information, so nobody would actually want to generate *just* this. Proposed solution ================= We should provide for the test-cases the stripped version of RDF metadata, and we should explicitly state that implementations are not required to exactly produce those RDF triples, but to produce something from which all those triples can be *inferred* using RDFS semantics. In RDF parlance, the RDF produced by an implementation for complete.mp3 should *entail* the RDF graph expressed by complete.ttl, under the entailment regime of RDFS. The drawback of this proposal is that it requires that testers use an inference engine. However, RDFS semantics is relatively well supported... pa [1] http://dev.w3.org/2008/video/mediaann/mediaont-1.0/mediaont-1.0.html#correspondence-between-the-informal-ontology-and-the-rdf-representation [2] http://lexvo.org/id/iso639-3/eng
Received on Wednesday, 16 March 2011 03:37:08 UTC