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Re: ISSUE-111 Proposal to Resolve

From: Jim Hendler <hendler@cs.rpi.edu>
Date: Tue, 19 Aug 2008 09:44:00 -0400
Cc: Bijan Parsia <bparsia@cs.man.ac.uk>, public-owl-wg Group WG <public-owl-wg@w3.org>
Message-Id: <A3C77A56-4A81-48E0-A6C6-5EF39849A988@cs.rpi.edu>
To: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>

Ian - sameAs^3, if made "THE" thing to use would solve the problem, it  
would just be very counterintuitive to real users -- I see no  
advantage over adding some small semantics free declarative to OWL  
Full documents (and remember it is only OWL Full) - and, I'm sorry,  
maybe you see me as being unreasonable, but I simply don't see any way  
I can sign on to the current proposal  --  Look, let me put it this  
way - you will not convince my organization that the sameAs^3 solution  
(esp. as curently set up where any error signals an intent) is a good  
one. We can go back and forth as much as you want, but my organization  
won't agree to the current closing text
  I know you don't like discussion of W3C process, but basically,  
going back and forth on this won't get us anywhere, you and I simply  
disagree - since you're involved in the discussion, Alan should either  
schedule a vote or propose an alternative and then we can move on -  
not every WG member needs to agree with everything, and I've stated my  
objection for the WG to consider so I've been treated fairly
  -JH


On Aug 18, 2008, at 4:13 PM, Ian Horrocks wrote:

> On 18 Aug 2008, at 17:04, Jim Hendler wrote:
>
>> Bijan,
>> It is absolutely true as you say that if it is in OWL Full then it  
>> is in OWL Full (you said it better), but the key here is we're  
>> talking about when the user explicitly wants to signal that it  
>> should be OWL Full -- seems to me having a very specific thing,  
>> easy to find, in this particlar (and probably rare) case would make  
>> everyone's lives easier -- I don't understand the reluctance, I've  
>> looked at the discussion in the f2f, and it seems to mainly concern  
>> general issues with signaling intent, which I mostly agree with,  
>> the problem is this one specific case - and why can't we just have  
>> some little piece of syntax, which is only in OWL Full, which  
>> basically says "Don't expect complete/sound reasoning if you use me  
>> with an OWL DL tool" - seems to me we could do something more  
>> mnemonic that sameas Sameas sameAs -- and would make things easier  
>> for both implementors and users
>
> sameAs^3 seems to do exactly what you want without the need to  
> introduce any new OWL RDF vocabulary, and it is at least easy to  
> remember (even if not mnemonic). I'm open to suggestions, though, as  
> to some other piece of OWL Full that could be used for the same  
> purpose -- but remember that one of the criteria is that it should  
> be vacuous (i.e., be entailed by every OWL Full ontology).
>
> Ian
>
>
>
>> Guess what I'm trying to ask is what would be the downside?  I can  
>> only see positive advantages as an implementor
>> -JH
>>
>>
>> On Aug 18, 2008, at 10:48 AM, Bijan Parsia wrote:
>>
>>>
>>> On 12 Aug 2008, at 13:10, Jim Hendler wrote:
>>>
>>>>
>>>> OK, so supposing I'm an OWL DL user and I want to use a DL  
>>>> reasoner.  I accidently, however, assert something that puts the  
>>>> ontology in Full (and when we did the analysis of 1500 ontologies  
>>>> 3 years ago, there were at least 100 for which this case was true  
>>>> -- usually because someone referred to something from a remote  
>>>> name space without adding the appropriate type or imported  
>>>> something that put them into Full without their realizing it) --  
>>>> so according to this, tools like Pellet, instead of "fixing"  
>>>> these mistakes (heuristically) would now need to assume the  
>>>> person knew what they were doing and that they want to be in Full
>>>
>>> No. If an ontology is syntactically in OWL Full it is in OWL Full.  
>>> This has *always* been true.
>>>
>>> How to *handle* OWL Full ontologies remains, as it was then, up to  
>>> the tool. Pellet performs an analysis and repair phase with  
>>> reports back on the repairs performed and a strict mode. Nothing  
>>> would change with that.
>>>
>>>> -- so it would be rare that they want to do this on purpose, but  
>>>> not rare that it would happen by accident.
>>>> My point is not that I think there shoudln't be some way to do  
>>>> this, but rather that it should be explicit -- otherwise we get  
>>>> in a situation where tools will assume it's a mistake, and then  
>>>> the user will have to do something extra to make it clear they  
>>>> meant it
>>>> So my argument is not that we should have some way to always  
>>>> signal intended use, but that for this corner case, we should  
>>>> have something unambiguous that is not likely to be used by  
>>>> mistake (which is why, sameAs sameAs sameAs seems appealing)
>>>
>>> I think if we give advice and follow that advice up with tools  
>>> support (e.g., in the report say, "This ontology is OWL Full only  
>>> in virtue of the notorious sameAs^3 triple which generally means  
>>> that this is intended to be owl full. This reasoner does not  
>>> support OWL Full semantics, would you like the (sound but  
>>> incomplete wrt subusmption) OWL DL results anyway?"
>>>
>>> Cheers,
>>> Bijan.
>>>
>>>
>>
>> "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 Tuesday, 19 August 2008 13:44:54 GMT

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