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RE: Chair's Concerns re: Test Cases and CR

From: Smith, Michael K <michael.smith@eds.com>
Date: Mon, 29 Sep 2003 11:19:14 -0500
Message-ID: <2928D6FE55D5584390909578CAC8397D02AB6A44@usplm216.txpln.us.eds.com>
To: Ian Horrocks <horrocks@cs.man.ac.uk>, Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>
Cc: webont <www-webont-wg@w3.org>

I agree with most of what has been said in this thread.

But, I would argue that use of oneOf is not really gratuitous.  We
needed at least one example in order to present the concept.  And the
selected uses are very similar and natural.  The example ontologies
must be DL and because they were contrived to use all of the language
it should not be surprising that they are a little odd.

That it has implications for efficiency for certain classes of
reasoners is important to know, and alternative, more efficient
formulations would be good to present.

Ian, what is the preferred, more efficient formulation?  Do you make
the constants into classes and define WineFlavor as a union rather
than collection?  And then what?  How do you rewrite 

  <WhiteWine rdf:ID="StGenevieveTexasWhite">
    <locatedIn rdf:resource="#CentralTexasRegion" />
    <hasMaker  rdf:resource="#StGenevieve" />
    <hasSugar  rdf:resource="#Dry" />
    <hasFlavor rdf:resource="#Moderate" />
  </WhiteWine>

Create an instance of a class Dry, to plug into the hasSugar relation?

- Mike

Michael K. Smith, Ph.D., P.E.
EDS - Austin Innovation Centre
98 San Jacinto, #500
Austin, TX  78701

phone: +01-512-404-6683
email: michael.smith@eds.com
  


-----Original Message-----
From: Ian Horrocks [mailto:horrocks@cs.man.ac.uk] 
Sent: Monday, September 29, 2003 10:52 AM
To: Frank van Harmelen
Cc: webont
Subject: Re: Chair's Concerns re: Test Cases and CR



On September 29, Frank van Harmelen writes:
> 
> 
> 
> Ian Horrocks wrote:
> 
> > the extensive use of oneOf in the wine and food
> > ontologies is largely gratuitous (it seems to be mainly the result of
> > their origin in a language that supported this constructor but did not
> > support unions of classes), and is setting a bad example to
> > prospective users - it encourages the use of statements that are, in
> > most cases, stronger than is needed/intended, and that are known to be
> > difficult to reason with.
> >
> > One further point. Given the elimination of oneOf, then the wine and
> > food ontologies could even be transformed into OWL Lite, although this
> > would result in some mangling of the syntax (in order to capture
> > negation and disjunction).
> 
> Jeremy Carroll wrote:
> 
> > I have code for that if needed.
> 
> I think all these points:
> 
> 1) be careful with oneOf's
> 2) without oneOf's, an ontology can often be transformed from DL into
Lite
> 3) that step can even be done automatically
> 
> are all very good points to make in whatever "style/how-to" guide we  will
be 
> writing.

Agreed, but w.r.t. point 1, our advice would carry more weight if we
were seen to be taking it seriously in our own example ontologies!

Ian



> 
> Frank.
>    ----
> 


-- 
Ian Horrocks, Department of Computer Science,
University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
Tel: +44 161 275 6133/6248  Fax: +44 161 275 6211
Email: horrocks@cs.man.ac.uk
URL: http://www.cs.man.ac.uk/~horrocks
Received on Monday, 29 September 2003 12:20:47 GMT

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