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Re: ISSUE-111 Proposal to Resolve

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Mon, 18 Aug 2008 15:48:52 +0100
Message-Id: <40E38A67-7F06-4AF9-8AE5-7F6DB4116F35@cs.man.ac.uk>
Cc: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>, public-owl-wg Group WG <public-owl-wg@w3.org>
To: Jim Hendler <hendler@cs.rpi.edu>

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.
Received on Monday, 18 August 2008 14:46:27 GMT

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