- From: Bill de hÓra <dehora@eircom.net>
- Date: Sat, 02 Aug 2003 12:33:36 +0100
- To: Tim Berners-Lee <timbl@w3.org>
- CC: "Roy T. Fielding" <fielding@apache.org>, Norman Walsh <Norman.Walsh@Sun.COM>, Public W3C <www-tag@w3.org>
Tim Berners-Lee wrote: Tim, > Sorry, but the semantic web architecture absolutely needs the idea > of information resources. The RDF identifier foo#bar is > used by dereferencing foo and parsing it a get information. Is it? I'm sure there are fragids out there that are being used as just proper names. And when it comes to machine reasoning, that is /all/ they are. The RDF MT explicitly does not care abut URI structure. You can't carry over that implication without going beyond the RDF MT. An RDF machine that did this would be embracing and extending RDF semantics in much the same way cwm does. To state, in a machine reasonable way that a URI denotes an information resource rather a non-information resource requires an ontology of resources - URI indexicals are not sufficient. If you are going to mandate a privileged status for URIS with fragids in the semantic web, then before the URI is forwarded to an RDF MT compliant reasoner that URI needs to be annonated with new triples that claims it is an information type resource. So, you /still/ need the resource ontology. This automagic must be stated explicitly in the architecture, as being automagic. That's not to say it isn't useful, people hack at URI structures every day to great effect, but as things stand it's beyond RDF and any semantic web MT I've seen. And I suspect this opens a Pandora's box of hacks, optimizations, localizations, my-need-is-special, non-portable extensions and presumptions to the semantics that involve frigging with URIs. You name it. This is since I don't see why we'd would stop carving things up at information resources, if that turned out to be useful. If so, where this heuristic annotating is done needs to be clearly outlined. Is there a layer for it? The more I think about it, the more this seems like a way of avoiding defining a new URI scheme for the semantic web by finessing the opacity axiom. Bill de hÓra
Received on Saturday, 2 August 2003 07:33:49 UTC