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Re: Proposed (parital) response to Ken Laskey and questions for WG

From: Jeff Heflin <heflin@cse.lehigh.edu>
Date: Wed, 16 Jul 2003 10:15:26 -0400
Message-ID: <3F155DFE.E35DF043@cse.lehigh.edu>
To: Jim Hendler <hendler@cs.umd.edu>
CC: WebOnt <www-webont-wg@w3.org>


Point taken. I also prefer  your second suggestion (i.e., change
"typically" to "assumed to be".

Before I send the message I'd like to see if the WG has a preference on
whether or not we need to include some discussion of how OWL meets our
requirements somewhere in our document set. This was a theme that ran
throughout Ken's post.


Jim Hendler wrote:
> Jeff - I'm okay with this response except for one part (on the
> "typically" issue) - see below:
> At 3:14 PM -0400 7/14/03, Jeff Heflin wrote:
> [snip]
> >
> >>  <original section="2.2" paragraph="3">
> >>  An example of such knowledge would be that a "Late Georgian chest of
> >>  drawers" is typically made of mahogany. This knowledge is crucial for real
> >>  semantic queries, e.g. a user query for "antique mahogany storage
> >>  furniture" could match with images of Late Georgian chests of drawers, even
> >>  if nothing is said about wood type in the image annotation.
> >>  </original>
> >>
> >>  <comment>
> >>  OWL supports equivalence relationships but not probablistic relationships
> >>  such as "typically made of mahogany".  The concept "typically"would likely
> >>  be application-specific reasoning which might be supported by a value
> >>  mapping ontology, but this logic goes beyond OWL capabilities.  Suggest
> >>  adding to the end of the paragraph:
> >>
> >>  While OWL in its present form does not intrinsically support such
> >>  probablistic or conditional associations useful in real semantic queries,
> >>  application-specific semantics could be encoded in OWL to support such
> >>  functionality.
> >>  </comment>
> >
> >Actually, the use case was talking about defeasible inheritance
> >reasoning, not probability. Although probability can be clearly of use
> >in some use cases, the working group did not consider it an important
> >requirement, although support for probabilistic information is implied
> >by Requirement R12. Attaching Information to Statements. Therefore, I
> >decline the change.
> while I agree with what you say, I do think Ken is right to think
> that "typically made of" might imply probability -- and I don't agree
> that we did not consider this important -- it wasn't discussed (and
> would likely have been ruled out of scope if it had been).  I think
> we should addrerss this differently.  Here's two possibilities:
> We  could add a parenthetical at the end of this section addressing
> probabilities -- i.e. we could say something like:
> "in the image annotation.  (Note that we focus here on the notion of
> "default" reasoning.  Similar functionality might be provided by the
> addition of probabilistic information to statements (see R12 below)."
> or we could change the word from typical to something more directly
> connoting defaults:
> "...a `Late Georgian chest of drawers', in the absence of other
> information, would be assumed to be `made of mahogany.'  This
> knowledge ... "
> I slightly prefer the latter of these, suspect Ken would prefer the
> former - but I would approve the overall response if you made either
> of these two.
>   -JH
> --
> 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 Wednesday, 16 July 2003 10:15:33 UTC

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