- From: Sandro Hawke <sandro@w3.org>
- Date: Mon, 14 Jun 2004 22:52:13 -0400
- To: "John Black" <JohnBlack@deltek.com>
- Cc: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, public-sw-meaning@w3.org
> > > Again, why not the usual situation in the rest of the web? The > > > contents of Semantic Web web pages are asserted, just like other > > > web pages. > I don't agree that the default illocutionary force of a web page is > truth functional assertion of its propositions. The number of counter > examples must number in the millions. Here are a few: > > Sunset - http://www.nevis.columbia.edu/~hires/pictures/sunset.jpg > true? or false? Neither, for there are no propositions. The actually proposition content served from that address is more like: there exists an image which is 1152 pixels across and 770 pixels high, with a JPEG encoding with the following parameters, .... There's probably more connection between the URI and the image than "there exists....", but I'm not as sure how to formalize it. Pragmatically, if you do a web get on that URI, you'll be told (using standard protocols) that a particular image exists -- maybe that if-then is all the identification relationship we need. > "<foaf:Person rdf:about="#Peter_Frederick_Patel-Schneider"> > <rdf:type rdf:resource="#PerfectBeing" />" > - http://www-db.research.bell-labs.com/user/pfps/ > asserted? No, an example of what could happen if you were required > to believe everything said by the owner of a URI you used. Yes, it is asserted *by the web page*. It is not asserted by Peter (as far as I can tell). His relationship with his page is more complex than to simply assert everything it says. Connecting formal statements to real people may be doomed to failure -- who ever means precisely and exactly and literally much of anything they say? -- but connecting formal statements to artificial-constructs/agents/web-pages seems just fine to me. From there we can build together networks of trust, where one page asserts another. Perhaps http://example.com would assert every page starting with "http://example.com", making trust reasoning scale a lot better. (...essentially allowing one to reason about large sites, instead of individual pages.) I'm not sure whether it's fair to use owl:imports as the way for one page to assert another.... > "302.0 Homosexuality is a type of > Sexual Deviation" - http://www.wolfbane.com/icd/icd8h.htm. > asserted now? No, a historical record of what the World Health > Organization believed in 1965. Again, yes it is! The ICD Rev 8 (1965) is being faithfully represented on that page (as far as I know), and both it and the page claim that homosexuality is a type of "Sexual Deviation". I would not expect that Wolfbane Cybernetic Ltd (the domain's owner) holds that view. So I can say "I don't believe http://www.wolfbane.com/icd/icd8h.htm", or "I find http://www.wolfbane.com/icd/icd8h.htm offensive", without saying much of anything about wolfbane.com. I don't know of an RDF vocabulary for saying those things in RDF, but it shouldn't be too hard to specify (give or take trying to specify the meaning of things like the Liar Paradox which you could then construct). Of course I'd probably just publish a page which said that, so you wouldn't have a formal tie back to ME saying it, but DanBri suggested some ways one might attempt that. Aside from the problems of formalizing human expressions, achieving strong on-line non-repudiation in a world with insecure computers is a hard problem. And one we don't need to solve for the Semantic Web. Meanwhile, one could also publish a page which asserted that the ICD Rev 8 (1965) asserted that homosexuality was a type of what it called "sexual deviation"; that is, one could use some sort of quoting, given the right RDF vocabulary for it. But that's just syntactic sugar, since we can just put something on another page to quote it. -- sandro
Received on Monday, 14 June 2004 22:51:33 UTC