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RE: Proposed response to Martin Merry, HP

From: Jim Hendler <hendler@cs.umd.edu>
Date: Thu, 12 Jun 2003 21:31:01 -0400
Message-Id: <p05200f04bb0ed849a023@[10.0.1.2]>
To: "Smith, Michael K" <michael.smith@eds.com>, Jeremy Carroll <jjc@hplb.hpl.hp.com>, Guus Schreiber <schreiber@cs.vu.nl>
Cc: www-webont-wg@w3.org

At 10:21 AM -0500 6/12/03, Smith, Michael K wrote:
>If we feel the need to assert that complete reasoning in OWL DL
>is impractical, I presume we should go on to say that
>complete reasoning in OWL Full is impossible?  And that reasoning
>with any particular set of rules in OWL Full is unpredictable,
>unless the user has performed a complexity analysis on his rule set?
>
>- Mike
>

I'm confused as to why we would want to say more of these -- I think 
we have correctly explained the situation - the changes I proposed 
were aimed at setting the record straight - I don't agree with Jeremy 
we need "in your face" claims about things which probably won't 
matter to most users.  We've been extremely careful, and our design 
is strong - we should be clear, and that is why I proposed what I 
did, but we don't have to make it sound like things are broken -- 
they're not.
  -JH


>
>-----Original Message-----
>From: Jeremy Carroll [mailto:jjc@hplb.hpl.hp.com]
>Sent: Thursday, June 12, 2003 10:02 AM
>To: Smith, Michael K; Guus Schreiber; Jim Hendler
>Cc: www-webont-wg@w3.org
>Subject: RE: Proposed response to Martin Merry, HP
>
>
>
>I am less than convinced by text that is not more in-your-face.
>(this is not really meant as a response to Mike, more to Jim)
>
>
>>    Ontology developers adopting OWL should consider which species best
>>    suits their needs.  The choice between OWL Lite and OWL DL
>>    depends on the extent to which users require the more expressive
>>    restriction constructs provided by OWL DL.
>>  [NEW:
>>    Reasoners for OWL
>>    Lite will have desirable computational properties.  Reasoners for
>>    OWL DL, while dealing with a decidable sublanguage, will be subject to
>>    higher worst-case complexity.
>>  ]
>>
>
>this text still suggests that what we once called complete DL consistency
>checkers will exist. Since we have no evidence for this, and in fact we have
>evidence to the contrary, that should be made explicit: e.g.
>
>[
>    Reasoners for OWL
>    Lite will have desirable computational properties.
>Theoretically,  complete reasoners for
>OWL DL could be built, since it is a decidable sublanguage;
>however the worst-case complexity would probably be unacceptable.
>
>]
>
>OWL DL is primarily a theoretical constuct and a research hypothesis - not a
>proven practical level.
>
>Jeremy

-- 
Professor James Hendler				  hendler@cs.umd.edu
Director, Semantic Web and Agent Technologies	  301-405-2696
Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
Univ of Maryland, College Park, MD 20742	  *** 240-277-3388 (Cell)
http://www.cs.umd.edu/users/hendler      *** NOTE CHANGED CELL NUMBER ***
Received on Thursday, 12 June 2003 21:31:13 GMT

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