- From: Pat Hayes <phayes@ihmc.us>
- Date: Fri, 2 Mar 2012 23:12:40 -0600
- To: Antoine Zimmermann <antoine.zimmermann@emse.fr>
- Cc: Dan Brickley <danbri@danbri.org>, RDF WG <public-rdf-wg@w3.org>
On Mar 2, 2012, at 8:09 AM, Antoine Zimmermann wrote: > > > > Le 01/03/2012 20:16, Pat Hayes a écrit : >> >> 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. > > Impossible? From what do you conclude this? Um...biology? (Do you seriously believe that a document can be a person? Even the US Supreme Court hasnt quite gone that far yet.) > >> >> 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. > > http-range-14 has nothing to do with the semantics of OWL No, it does precisely at this point. Http-range-14 mandates that a successful 200-coded HTTP GET result means that the URi in question is the name of an information resource. So it can't refer to something else entirely. > , but let me tell you that what's retrieved by the HTTP lookup in this example is the document at http://zimmer.aprilfoolsreview.com/antoine, which is *not* the URI used in the owl:imports statement. I presume this is because the statement has a URI reference in it, and HTTP uses the URI with the post-hash stuff removed. So yes, in this case there are two different URIrefs involved: the one that is used in the retrieval, without a hash, denotes the ontology and the one with #me added denotes you. Which is kind of odd, but does make sense. The oddity comes from using a hash URIref in an owl:imports, of course. Bad practice. Pat > > >> >> 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. Did you mean to write the second one differently? >>> >>> 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 >> >> >> >> >> >> > > -- > 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 Saturday, 3 March 2012 05:13:18 UTC