- From: Bernard Vatant <bernard.vatant@mondeca.com>
- Date: Thu, 14 Jun 2007 11:24:15 +0200
- To: Pat Hayes <phayes@ihmc.us>
- Cc: Richard Cyganiak <richard@cyganiak.de>, semantic-web@w3.org
Richard >> Here are two web pages about me: >> >> <http://richard.cyganiak.de/> >> <http://ontoworld.org/wiki/Richard_Cyganiak> >> >> One is in German, the other in English: >> >> <http://richard.cyganiak.de/> dc:language "de" . >> <http://ontoworld.org/wiki/Richard_Cyganiak> dc:language "en" . >> >> You say it's OK to use a web page URL to denote the person it's >> about, so: >> >> <http://richard.cyganiak.de/> a foaf:Person . >> <http://ontoworld.org/wiki/Richard_Cyganiak> a foaf:Person . >> >> Both clearly denote the same person, so we can confidently state: >> >> <http://richard.cyganiak.de/> >> owl:sameAs <http://ontoworld.org/wiki/Richard_Cyganiak> . Pat > Ah, no. You can't do that so, er, confidently. After all, you are > punning, using the same URI to denote several things, so you should > only say they are equal in this strong sense when they are equal in > ALL their uses. And of course they aren't: they denote different web > pages. If I follow you (and I generally do on those issues, even if it gives me hard time), using owl:sameAs this way is always meaning much more than the assertion's author generally thinks. So you agree with the point I made in the Linking Open Data forum that e.g http://dbpedia.org/resource/Berlin owl:sameAs http://sws.geonames.org/2950159/ is exactly the same case, and we should not have done that, right? I hope Richard will get the point from you better than from me. :-) >> This allows us to conclude: >> >> <http://richard.cyganiak.de/> dc:language "de" . >> <http://richard.cyganiak.de/> dc:language "en" . >> >> Which is obviously wrong. So what did I do? > > You overused owl:sameAs. Repeat after me, Richard : you/we/they OVERUSE owl:sameAs :-) > Logical equality has to be used with care when punning, its true. This > is why OWL 1.1 will (at the time of writing) have three distinct > equalities, Good news, but could you expand on this, and/or provide pointers to the OWL 1.1 document(s) defining those three different equalities? > and why the CL semantics uses true semantic overloading rather than > punning, speaking strictly. > BTW, I opposed including owl:sameAs, i.e. simple equality, into OWL > for exactly this reason. But I was overruled :-) Too bad indeed. > But you have made a very nice case, which nobody has made to me before. Well, I thought I'd made a similar one two days ago with the GeoNames / DBpedia case at [1] ... but you seem to have missed it. This thread is tricky to follow :-) http://lists.w3.org/Archives/Public/semantic-web/2007Jun/0123.html Bernard -- *Bernard Vatant *Knowledge Engineering ---------------------------------------------------- *Mondeca** *3, cité Nollez 75018 Paris France Web: www.mondeca.com <http://www.mondeca.com> ---------------------------------------------------- Tel: +33 (0) 871 488 459 Mail: bernard.vatant@mondeca.com <mailto:bernard.vatant@mondeca.com> Blog: Leçons de Choses <http://mondeca.wordpress.com/>
Received on Thursday, 14 June 2007 09:24:24 UTC