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Re: [OWLWG-COMMENT] Example why current RDF mapping for QCRs might hurt OWL-1.1-Full

From: Jim Hendler <hendler@cs.rpi.edu>
Date: Mon, 17 Dec 2007 08:55:22 -0500
Message-Id: <04012C69-03E8-4275-B25B-0D3485A71B89@cs.rpi.edu>
Cc: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, Michael Schneider <schneid@fzi.de>, Owl Dev <public-owl-dev@w3.org>, Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>, Alan Ruttenberg <alanruttenberg@gmail.com>, OWL Working Group WG <public-owl-wg@w3.org>
To: Matthew Pocock <matthew.pocock@ncl.ac.uk>
Matthew, I agree -
I don't have any objection to QCRs, and agree w/you that it is the  
ecnoding we should fix

<flame on - but not at Matthew>
-but  I note also that there are many widely used KR features lefts  
out of OWL because the WG either does not have consensus on how to  
define, or apparently, now things are left out if they aren't  
decidable in OWL DL (I note the most used OWL feature of any ontology  
to date, the inversefunctional email sha-sum of FOAF, would not have  
been accepted under this rule) -- there are lots of such examples  
Part/whole being the obvious - it is used in the gene and OBO  
ontologies, and in most of the scientific ontologies I've seen for  
physics, astronomy, and geology - but the OWL 1.0 WG punted on it and  
the OWL 1.1 hasn't even considered it.  I'd like to see the WG being  
a bit more consistent with respect to deciding what will and will not  
be used.  I see the current 1.1 design as something of a hodgepodge,  
with KR considerations being far more weighted than other issues -  
decidability has become a requirement (without any rewrite of the  
requirements document that I ca find) and people are doing what I see  
as very arrogant, such as people telling the Oracle rep what it is  
that his customers should want - rather than listening to Oracle  
explain what Oracle needs and wants
<flame off>

sorry had to get that off my chest
  -JH




On Dec 17, 2007, at 8:09 AM, Matthew Pocock wrote:

> 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
>
>

"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 13:56:25 GMT

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