- From: Sandro Hawke <sandro@w3.org>
- Date: Thu, 16 Oct 2003 15:16:58 -0400
- To: public-sw-meaning@w3.org
I'm trying to do something totally reasonable with RDF and the web, but I find myself going against a WebArch "good practice". How could I possibly do this better? This smells to me like a leak in WebArch notion of URIs, but I brought it here because it's close enough to the hoses connecting WebArch to RDF Semantics. We have four URIs: (M1) http://www.w3.org/2002/03owlt/equivalentClass/Manifest003#test This is what the WebOnt WG decided to name a particular OWL test. You, as a human or machine, can learn more about the test by dereferencing the URI (doing an HTTP GET). You should get back some RDF/XML information about the test. A nicely formatted version of that information (plus some more you'd get by following some more links) is at: (H1) http://www.w3.org/TR/owl-test/L#equivalentClass-003 Meanwhile, I've been assembling an aggregation of results for OWL tests. As a human, today, you can visit (H2) http://www.w3.org/2003/08/owl-systems/test-results-out#test57 and see a row in a table about this test. You'll see it's a pretty easy one. (Even my fairly-lame OWL reasoner passed it!) That's also not a very stable fragment id. Next week it might land you on the results of another test. Sorry. But that's part of what I'm trying to fix. Mostly, though, I want to allow more varied views of the same data. I want to provide that data in RDF! I think the right approach is to use a URI like (M2) http://www.w3.org/2003/08/owl-systems/test/equivalentClass-003#test which can be used in RDF like M1, denoting the same test, but which on dereference provides the test results data, along with a triple saying it's owl:sameAs M1. [1] This seems reasonable, doesn't it? Two names for the same thing; when you follow them you get information about the thing; you get different information when you follow different names. For some applications you'll use the first name, for others the second. There are other people building test-results browsers; they should have access to the same data. Useful, practical, easy to do, and... seemingly contrary to TAG advice. The current WebArch document says, "If a URI has been assigned to a resource, Web agents SHOULD refer to the resource using the same URI, character for character." [2] So where is the breakdown here? Is this just the normal RFC 2119 escape from a "SHOULD": "there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course." If so, I wish the document would spell this out better, saying what some reasonable exceptions might be. It seems to me a lot like having two web pages about the same topic. Surely that's not something Web Arch wants to warn against. Maybe this is just a natural outgrowth of using URIs simultaneously as (1) logical constant symbols naming objects in some domain of discourse and (2) network addresses naming virtual end-points for communication. Since we're using them in two ways at the same time, they can be equivalent in one way, while being completely different in another. -- sandro [1] Actually, I want to use 303-See-Other redirection instead of a fragment URI, so I can merge in the human-readable view as well, but that's orthogonal, so I'll pretend otherwise for now. [2] http://www.w3.org/TR/2003/WD-webarch-20031001/#identifiers-comparison
Received on Thursday, 16 October 2003 15:15:56 UTC