- From: Matthew Pocock <matthew.pocock@ncl.ac.uk>
- Date: Mon, 17 Dec 2007 13:09:26 +0000
- To: Jim Hendler <hendler@cs.rpi.edu>
- Cc: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, schneid@fzi.de, public-owl-dev@w3.org, ian.horrocks@comlab.ox.ac.uk, alanruttenberg@gmail.com
We use QCRs in the Comparagrid domain ontology. I think it's also the only way to constrain what kinds of things participate in specific kinds of processes using BFO. So, from the end-user perspective, they are a vital bit of expressivity. The work-arround is to introduce syntactic sub-properties to float the restrictions on, but then bad things happen when you try to infer things because the property hierachy can't be closed off (covering constraints on properties). So I guess what I'm sudgesting is that you fix the RDF encoding of QCRs, rather than removing this feature from owl 1.1. Matthew On Monday 17 December 2007, Jim Hendler wrote: > I remind you all that the WG reopened the case of QCRs due to Alan > Rector's comments. At that point we found no concrete syntaxfor > which there was a consensus and we chose to POSTPONE the issue - I > don't see that the situation has changed - if the OWL 1.0 WG felt > that the DAML solution was appropriate we certainly would have chosen > to add it when we reopened the issue. We didn't - and I don't see > what has changed -- there's still very few users demanding it, and it > still requires creating an arbitrarily ugly and confusing syntax. > WHen I thought the OWL 1.1 syntax worked, I was happy with this, but > now that it has been exposed to have troubles, I don't see going back > to earlier solutions that were already rejected as a way out - seems > to me work should go into fixing what is there, and if that is > undoable, postpone again. > -JH > > On Dec 17, 2007, at 3:24 AM, Peter F. Patel-Schneider wrote: > > The resolution to not include QCRs in OWL had the following rationale > > http://lists.w3.org/Archives/Public/www-webont-wg/2002Apr/0264.html > > (numbering added): > > > > The qualified restrictions of DAML+OIL: > > 1/ - have added to the difficulty of learning the language > > 2/ - have not been used in practice > > 3/ - are barely understood by the community > > 4/ - potentially add to the difficulty of implementing the language > > 5/ - have no compelling use cases > > > > > > Since then there have been multiple calls for the expressive power of > > QCRs, including the one by Alan Rector back in 2003, overturning at > > least points 2 and 5. The use of QCRs at least partly overturns point > > 3. Several implementations of QCRs exist in both UI tools (e.g., > > Protege 4) > > and reasoners (e.g., Pellet), overturning point 4. > > > > I think that this is quite a significant change from the situation in > > 2002. > > > > Peter F. Patel-Schneider > > Bell Labs Research > > > > PS: For more information on QCRs in the WebOnt WG, see > > http://www.w3.org/2001/sw/WebOnt/webont-issues.html#I3.2-Qualified- > > Restrictions > > > > > > > > From: Jim Hendler <hendler@cs.rpi.edu> > > Subject: Re: [OWLWG-COMMENT] Example why current RDF mapping for > > QCRs might hurt OWL-1.1-Full [Re: PROPOSAL to close ISSUE-68] > > Date: Sun, 16 Dec 2007 17:18:32 -0500 > > > >> I have no objection to the solution that was used in OWL 1.0 for > >> this. So far, if a feature adds problems to DL, we apparently throw > >> it out immediately, but if it causes problems to full, we try to find > >> a work around without worrying too much if it cases problems or > >> confusion - I just fine this asymmetry to be troubling. So I propose > >> we don't include QCRs, since the solution proposed is one that was > >> already considered and rejected in OWL 1.0 - what has changed? > >> -JH > > "If we knew what we were doing, it wouldn't be called research, would > it?." - Albert Einstein > > Prof James Hendler http://www.cs.rpi.edu/~hendler > Tetherless World Constellation Chair > Computer Science Dept > Rensselaer Polytechnic Institute, Troy NY 12180
Received on Monday, 17 December 2007 13:09:55 UTC