- From: Ian Horrocks <horrocks@cs.man.ac.uk>
- Date: Fri, 8 Nov 2002 15:08:33 +0000
- To: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>
- Cc: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, <www-webont-wg@w3.org>
On November 8, Jeremy Carroll writes: > > I wrote: > > Reasoning components MAY claim "most of OWL DL reasoning" if > > they provide at > > least OWL Lite reasoning and ... [tbd] (e.g. pass 90% of the tests). > > I heard: > 90% is a very bad idea. No you didn't - you heard that any notion of conformance based on some inevitably subjective measure of "most" is a VERY BAD idea. > > I didn't hear alternatives for the [tbd] ... For obvious reasons given the above. > > Suggestions please. Don't tempt me. > > Ian: > >What now seems to be suggested is that the language is more or less > >the same as OWL DL, and that ease of implementation is instead due to > >different requirements w.r.t. implementation. Why bother with OWL Lite > >at all in this case? > > The proposal with the OWL Lite conformance is that it respects the syntactic > subset issues, *and* OWL Lite reasoners may be less powerful than OWL DL > reasoners, even over that syntactic subset. You are missing the point. If we were to go down this route (heaven forbid), there would be no reason to have a syntactic subset - you could just weaken the conformance criteria for the OWL DL language until ease of implementation was judged to be the same, e.g., we could decide that 80% correct for OWL DL is just as easy to implement as 90% correct for OWL Lite. This would save all the trouble of specifying 2 different languages. And just in case there is any doubt, I don't intend the above as a serious suggestion! > However, I take it for granted that we would want an OWL DL reasoner to > automatically be an OWL Lite reasoner, so the underlying semantics is the > same. > > I realize this is coming from a different direction than a theoretical study > of the complexity problems of different constructs for complete reasoners. > > So proposal is OWL Lite = OWL DL - some of the > hard-to-implement-complete-reasoning-for-cosntructs > *and* OWL Lite reasoners may be incomplete in some well defined way over > that subset. > > This leaves OWL DL as a distinguished conformance point where reasoning is > complete. > We may want to have a conformance description for complete OWL Lite > reasoners, but, on your analysis it doesn't seem we would have many takers > other than those who are really shooting at OWL DL reasoning. I strongly disagree. I believe that the current specification of OWL Lite is very amenable to complete implementation and that this will be the target for many implementors. Ian > > Jeremy > > > > >
Received on Friday, 8 November 2002 10:04:36 UTC