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Re: ISSUE-55 (owl:class)

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Sun, 2 Dec 2007 19:46:27 +0000
Message-Id: <22D90D85-EB33-48D8-B5E2-E46B07C0BFAC@comlab.ox.ac.uk>
Cc: OWL Working Group WG <public-owl-wg@w3.org>
To: Jim Hendler <hendler@cs.rpi.edu>
See the emails on this issue, in particular http://lists.w3.org/ 
Archives/Public/public-owl-wg/2007Nov/0263.html and http:// 
lists.w3.org/Archives/Public/public-owl-wg/2007Nov/0258.html, for an  
explanation of the significant and not fully understood technical  
difficulties.

IMHO, if it goes anywhere this should go in some UFD giving advice on  
"repairing" ontologies (see also ISSUE-56).

Ian


On 2 Dec 2007, at 18:27, Jim Hendler wrote:

> My request in raising the issue was that if we postponed it, we  
> needed a clear statement as to why the problem exists (and several  
> people have suggested adding the note that many reasoners change  
> rdfs:class to owl:class despite the semantic issue) -- saying "  
> introduces significant and not fully understood technical  
> difficulties" does not satisfy what I asked this issue to be  
> addressed for.  Again, in studies of ontologies out there, a great  
> many OWL Full ontologies become OWL DL with this change, I would  
> think that it would therefore be incumbent on this group to either  
> encourage those users to use owl:class (by explaining why they  
> should) or make it clear they can still work with OWL DL tools if  
> they don't, but there are certain techniical risks (which I must  
> admit I still don't understand)
>  So if we postpone this issue, which I'm okay with, it requires an  
> explanation - and that is where I think we (the OWL community) has  
> failed to date.   In fact, I've been suggesting to my students that  
> they use rdfs:class in many applications since OWL DL tools fix it,  
> and RDF-only tools don't reject it...  this is clearly wrong  
> semantically (Which I explain to the best of my limited ability)  
> but right from a practical point of view...
>   -JH
>
>
>
>
> On Dec 1, 2007, at 3:07 PM, Ian Horrocks wrote:
>
>>
>> I'm tending to postpone this issue on the grounds that it  
>> introduces significant and not fully understood technical  
>> difficulties.
>>
>
> "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 Sunday, 2 December 2007 19:46:45 GMT

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