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OWL Comment: have long CR period for OWL, or move owl:oneOf, owl: have Value to OWL Full

From: Merry, Martin <Martin_Merry@hplb.hpl.hp.com>
Date: Fri, 9 May 2003 15:18:27 +0100
Message-ID: <5E13A1874524D411A876006008CD059F030CAAB0@0-mail-1.hpl.hp.com>
To: public-webont-comments@w3.org

We wish to comment on the usefulness of OWL DL as a sensible subset of OWL
Full.

We're concerned that OWL users should have their expectations met when they
use OWL compliant systems.

We find that the draft documents make it clear that OWL Full systems will
not have full reasoning support and that therefore users will not be too
surprised when there is a resulting migration cost from one OWL Full system
to another.

We are concerned, however, that OWL DL is presented as a sensible stopping
point before OWL Full, where there are greater guarantees. 

The theoretical results for the decidability of OWL DL are interesting but
not particularly helpful. OWL Lite is justified by practical results in DL
systems (primarily from Ian Horrocks). There is no such practical experience
for the OWL DL subset.  We would like to see such practical experience
before OWL exits candidate recommendation.

In particular, we would like to see adequate practical implementation
experience of the OWL DL constructs owl:oneOf and owl:hasValue.  We believe
that this should include the goal that OWL DL reasoners can make a
reasonable attempt at classic NP complete problems (such as the 3-SAT
problem and the subgraph isomorphism problem) which can be straightforwardly
encoded within OWL DL.  For example, any such problem that can be solved in
seconds by a specialised reasoner should be soluble by a general OWL DL
reasoner in minutes rather than years.

An alternative, would be to redefine OWL DL downwards, excluding owl:oneOf
and owl:hasValue, which would then be subject to the health warnings of OWL
Full - i.e. use of these constructs means that your ontology is likely to be
outside the limits of practical reasoning. Such a redefinition of OWL DL,
could sensibly accompany a redefinition of OWL Lite to exclude complete
class definitions.


Martin Merry
HP Semantic Web Programme Manager
Received on Friday, 9 May 2003 10:20:06 GMT

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