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Re: ISSUE-111 Proposal to Resolve

From: Jim Hendler <hendler@cs.rpi.edu>
Date: Tue, 12 Aug 2008 08:10:57 -0400
Cc: public-owl-wg Group WG <public-owl-wg@w3.org>
Message-Id: <F9B84981-FEB2-465E-BC7A-610A7AE6F675@cs.rpi.edu>
To: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>

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 -- 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) -- but we should have one  
specific way to do it or else we create the potential for use  
confusion and non-interoperability since we'll end up with computers  
trying to guess human intentions -- something they are not good at
  Seems to me the easy solution in this case is to be insistent that  
some very specific triple get asserted in this rare case (and not that  
we have a general mechanism for intended use) which would solve  
Bijan's problem of creating something overly general (and, since it  
would only be used in this case, the complexity of "conflicting"  
intendedUse Triples is a non-issue)
   -JH



On Aug 11, 2008, at 2:50 PM, Ian Horrocks wrote:

>
> The proposal *is* that there would be no specified way to signal the  
> intended semantics, so tools would have their choice. Thus I'm not  
> sure why you don't like it. Perhaps I didn't explain it very well  
> (in my defence I should say that I was only trying for a very quick  
> summary of the cited discussions).
>
> The idea is to include only the advice/observation that including a  
> triple that takes the ontology out of OWL DL obviously forces it to  
> be interpreted using the RDF semantics, with "sameAs sameAs sameAs"  
> being given as an example of such a triple (I should have said "for  
> example" instead of "namely").
>
> Regards,
> Ian
>
>
> On 8 Aug 2008, at 17:33, Jim Hendler wrote:
>
>> Having left the WG, I seem to still be being pulled in a lot by  
>> side emails, so let me state, as RPI AC rep, that we don't like  
>> this solution.  I see two problems
>> 1 - it seems to us that people who use DL are more likely to  
>> understand the difference between DL and Full than those who are  
>> just using the vocabulary, so the chances of this triple being  
>> included seem very low - thus, we'd prefer to see someone who  
>> understands that they want to be only DL should have to do  
>> something to signal that
>> 2 - by this decision, if a user accidently does something to make  
>> their ontology OWL Full, they will be signaling they only want to  
>> be in Full (since it says "should include a triple that takes the  
>> ontology out of OWL DL") -- if the meaning is that we want users to  
>> use only this specific triple, then it seems to me we should do  
>> something more obvious, like putting in some semantics free  
>> definition that expresses intent -- i.e. instead of "sameAs sameAs  
>> sameAs" wouldn't it be a lot smarter for the document to include  
>> "[] intendedUse OWL-Full"?
>>
>> In fact, given these two factors, it seems like we should either  
>> have explicit means for signaling semantics when intended, or no  
>> specified way, meaning tools have their choice.
>>  -JH
>> AC Rep, RPI
>>
>>
>> On Aug 8, 2008, at 11:31 AM, Ian Horrocks wrote:
>>
>>>
>>> As per discussions and strawpolls at the Boston F2F [1] and our  
>>> most recent telecon [2], I propose that we close this issue by  
>>> adding to the spec the advice that users wanting to ensure that  
>>> their ontology is interpreted *only* as OWL Full should include a  
>>> triple that takes the ontology out of OWL DL, namely:
>>>
>>> sameAs sameAs sameAs .
>>>
>>> Regards,
>>> Ian
>>>
>>> [1] http://www.w3.org/2007/OWL/meeting/2008-07-28#Strawpoll_on_signaling_semantics
>>> [2] http://www.w3.org/2007/OWL/meeting/2008-08-06#Strawpoll_on_resolving_issue__2d_111
>>>
>>
>> "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, 12 August 2008 12:11:36 GMT

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