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Re: ISSUE-111 Proposal to Resolve

From: Jim Hendler <hendler@cs.rpi.edu>
Date: Tue, 19 Aug 2008 11:40:27 -0400
Cc: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>, public-owl-wg Group WG <public-owl-wg@w3.org>
Message-Id: <E51CAE71-90C6-4439-AD9D-5926AD429D4E@cs.rpi.edu>
To: Bijan Parsia <bparsia@cs.man.ac.uk>

So we're back to the same point - we disagree and need to move  
forward.  I can live with either a specific tag or no tag at all - I  
have problems with using this particular random piece of syntax for  
odd reasons.  You disagree.  I think that sums things up.
    -JH



On Aug 19, 2008, at 11:39 AM, Bijan Parsia wrote:

> On 19 Aug 2008, at 16:21, Jim Hendler wrote:
>
>> but isn't that a circular argument
>
> No.
>
>> -- you say people will use sameAs sameAs sameAs to signal intent,
>
> No. sameAs sameAs sameAs makes the ontology OWL Full.
>
>> but it will be bad for them to have to have something to signal  
>> intent.
>
> I think think we revealed enough issues with signaling user intent  
> in generally that we don't have good grounds for moving forward.
>
>> Basically, my problem is that I firmly believe that in language  
>> design the overloading of terms is a bad idea
>
> We aren't.
>
>> .  SameAs has a very specific meaning and it is highly used -  
>> someone seeing sameAs sameAs sameAs in an ontology seems to me to  
>> be much more likely to be confused than someone seeing  
>> "owl2:OWLFullOnly" or whatever semantics free tag
>
> It, by definition, isn't semantics free. It affects the semantics of  
> the document.
>
>> we use -- we could even put it within the ontology header --- seems  
>> to me you still haven't really shown me a downside
>
> It clearly involves 1) additional complexity to the language and 2)  
> potential cause for misunderstanding of its actual effect.
>
> I would have been much more sanguine about this (since its what I  
> proposed) if several people didn't immediately start wondering how  
> it affects imports, other tools, etc.
>
> The experience thus far hasn't been good. That seems enough for me.
>
>> -- you say the downside is that people would need to signal intent,  
>> but then propose a solution where they still have to signal intent,  
>> just in a less transparent way
>
> They don't signal *intent*. They just have made their ontology  
> actually unambiguously OWL Full. That's a big difference.
>
>> btw, I'm also fine with a solution where there is no signaling at  
>> all for OWL Full, which might be the compromise -- the thing I  
>> don't like is the overuse of existing syntax - so another  
>> alternative is to simply leave things as they are in OWL 1.0 (i.e.  
>> that ontologies are what they are) - would that be more acceptable?
>
> Since it's only advice I don't see that we've changed things. The  
> point is that we *haven't* changed things! We've just pointed out a  
> possible work around for the few folks (like Sandro) who care. This  
> is why Ian doesn't want to make the triple mandatory.
>
>> -JH
>> p.s. And again, let me stress that I would suggest we only create  
>> one term, and it is only intended for OWL Full only
>
> But then you get people asking, "Why only OWL Full? Why not for EL?"  
> and away we go :(
>
>> -- I do indeed agree that generally signaling intent is a bad idea  
>> - but if the WG feels it is needed for some reason in this case  
>> only, then we should do something explicit.
>
> The situation is that some people (e.g., Sandro) have indicated  
> discomfort with the fact that some ontologies are not syntactically  
> distinguishable as OWL DL or OWL Full. We considered adding a  
> general intent signalling mechanism but it ran into a lot of  
> problems. Thus we pulled back and said, "IF you care about this,  
> THEN you can ensure that your OWL Full ontologies are definitely  
> syntactically OWL Full by including a trivially entailed triple such  
> as sameAs^3."
>
> This involves *no change* to the language. It is not required. It  
> doesn't change the tool chain in any way. It doesn't change the  
> conceptual model of the language in any way.
>
> 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
Received on Tuesday, 19 August 2008 15:41:11 GMT

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