- From: Pat Hayes <phayes@ihmc.us>
- Date: Thu, 1 Mar 2012 13:16:50 -0600
- To: Antoine Zimmermann <antoine.zimmermann@emse.fr>
- Cc: Dan Brickley <danbri@danbri.org>, RDF WG <public-rdf-wg@w3.org>
On Mar 1, 2012, at 2:50 AM, Antoine Zimmermann wrote: > Le 01/03/2012 08:48, Dan Brickley a écrit : >> >> >> On Wednesday, 29 February 2012, Antoine Zimmermann wrote: >> >> [...] >> >> If I say in an ontology document: >> >> <> owl:imports <http://zimmer.aprilfoolsreview.com/antoine#me>. >> >> then, what I get, according to the OWL specs, is an ontology with >> the content of http://zimmer.aprilfoolsreview.com/antoine included, >> in spite of <http://zimmer.aprilfoolsreview.com/antoine#me> denoting >> a foaf:Person. >> >> Please take a look at the OWL 2 spec section 3.2 to check. >> >> >> Why should an ontology's RDF description not include information >> about real-world entities? > > On the contrary, it should. It is not what I said. I say that the import mechanism does not care about what kind of entity is denoted by the IRI used with owl:imports. No, it does care. If http-range-14 is correct, then that URI has to denote an information resource. > In the example above, the owl:imports statement implies (in the OWL 2 RDF based semantics, which is certainly the one the RDF WG is most interested in) that <http://zimmer.aprilfoolsreview.com/antoine#me> is an ontology, but after the import is effective via a HTTP lookup, it will be inferred that <http://zimmer.aprilfoolsreview.com/antoine#me> is a foaf:Person as well. This is consistent, as nothing says that ontologies cannot be people, Actually it is impossible for an OWL ontology document (which is what gets retrieved) to be a person, and there might even be true ontologies out there which assert this. This discussion is clearly deeply involved with the whole http-range issue. If we accept the TAG ruling on http-range-14, at least for now, and if the http retrieval in this example returns a 200-level coded response without any redirection, then we do have to assume that the URI denotes an "information resource", ie a Web document, more or less. And hence that it cannot be a person (or maybe better, it would be false and dangerous to move ahead with any infernce that was based on such a claim, as it is false and very liable to be contradicted by an accepted and authoritative ontology somewhere.) So I dont thikn we can be so blasé as you would like us to be about situations like this. Pat > but it may seem weird to some people. But look at the following example: > > > <> owl:imports <http://xmlns.com/foaf/0.1/#stuff> . > <http://xmlns.com/foaf/0.1/#stuff> owl:sameAs <http://dbpedia.org/ontology/> . > > This will import the FOAF ontology (assuming the application is doing a HTTP lookup). However, this: > > <> owl:imports <http://dbpedia.org/ontology/> . > <http://xmlns.com/foaf/0.1/#stuff> owl:sameAs <http://xmlns.com/foaf/0.1/#stuff> . > > will import the dbpedia ontology. > > In spite of owl:sameAs being formally interpreted as identity, these two ontologies will eventually have very different inferences. This is because the mechanics behind owl:imports is not part of the model theory of OWL. > >> >> Dan >> >> >> >> >> At the very least, if we mandate this, then we need to clarify the >> semantic role of "label" URIs in datasets. >> >> Pat >> >> ------------------------------__------------------------------ IHMC >> (850)434 8903 or (650)494 3973 40 South Alcaniz St. (850)202 4416 >> office Pensacola (850)202 4440 fax FL >> 32502 (850)291 0667 mobile >> phayesAT-SIGNihmc.us http://www.ihmc.us/users/__phayes >> <http://www.ihmc.us/users/phayes> >> >> >> >> >> >> >> >> -- Antoine Zimmermann ISCOD / LSTI - Institut Henri Fayol École >> Nationale Supérieure des Mines de Saint-Étienne 158 cours Fauriel >> 42023 Saint-Étienne Cedex 2 France Tél:+33(0)4 77 42 83 36 >> Fax:+33(0)4 77 42 66 66 http://zimmer.__aprilfoolsreview.com/ >> <http://zimmer.aprilfoolsreview.com/> >> > > > -- > Antoine Zimmermann > ISCOD / LSTI - Institut Henri Fayol > École Nationale Supérieure des Mines de Saint-Étienne > 158 cours Fauriel > 42023 Saint-Étienne Cedex 2 > France > Tél:+33(0)4 77 42 83 36 > Fax:+33(0)4 77 42 66 66 > http://zimmer.aprilfoolsreview.com/ > > ------------------------------------------------------------ IHMC (850)434 8903 or (650)494 3973 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 mobile phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
Received on Thursday, 1 March 2012 19:17:39 UTC