- From: Dan Connolly <connolly@w3.org>
- Date: Tue, 04 May 2004 16:07:50 -0500
- To: Rob Shearer <Rob.Shearer@networkinference.com>
- Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
On Tue, 2004-05-04 at 15:45, Rob Shearer wrote: > > > in fact it > > > codifies that any such extension is explicitly illegal. > > Queries along > > > the lines of "must these two nodes be related via either of > > these two > > > properties?" suddenly become impossible to answer when that > > answer is > > > derived via inference, or rules, or some higher-level > > semantic language. > > > > I don't understand how you come to that conclusion. > > > > Our charter addresses this pretty clearly, no? > > > > "1.8 Derived Graphs > > > > The working group must recognize that RDF graphs are often constructed > > by aggregation from multiple sources and through logical > > inference, and > > that sometimes the graphs are never materialized. Such graphs may be > > arbitrarily large or infinite." > > -- http://www.w3.org/2003/12/swa/dawg-charter#derivedGraphs > > "Logical inference" extends a *lot* farther than just appending triples > to an RDF graph. > There are a lot of ways to say "at least one of these two edges needs to > exist". Aha! Now I get it. Thanks for spelling it out (again? several times now?) Gee... I was being pretty dense. Hmm... I think I need to talk this over with a few other people that were involved in writing the charter. Meanwhile, I can see your point about this requirement. I leave it to the advocates to try to convince you. > It can be a consequence of an OWL ontology; it can be a > consequence of a rule encoded in a rules language; it can be a > consequence of any semantic layer you want to put on top of the basic > RDF data model. It does explicitly say something about what RDF graphs > are possible and what are not. But such knowledge does not necessarily > have any sensible encoding in RDF itself. [...] -- Dan Connolly, W3C http://www.w3.org/People/Connolly/ see you at the WWW2004 in NY 17-22 May?
Received on Tuesday, 4 May 2004 17:07:47 UTC