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

From: Jonathan Borden <jonathan@openhealth.org>
Date: Tue, 15 Jul 2003 19:04:27 -0400
Message-ID: <02a401c34b25$7413be70$b6f5d3ce@svhs.local>
To: "webont" <www-webont-wg@w3.org>, "Jim Hendler" <hendler@cs.umd.edu>

Re: Revisiting AllDisjoint (was Proposed (parital) resOk, fair enough. I
have no real opposition to AllDisjoint in any case. Its just that we've
decided to trash other features (e.g. QCRs and structured datatypes) which
aren't mere optimisations. But in all fairness the fact that I am concerned
that we may not have made the ideal choice in the past doesn't mean I should
object to our making the correct choice at this time. *


* p.s. such taxonomies tend not to be as broad as they appear. i.e. although
there may be 4675 different kinds of lizards and 2940 different kinds of
snakes, I suspect that such categories have their own internal heirarchy.
but no matter.

Jim Hendler wrote:

Jonathan - lets take a simpler example from outside medicine (so you have
less advantage over me).  Here's a use case that was sent in once earlier,
and appears in our record [1] - If I had a list of all the different
reptiles (for example), it would be very useful in classifying a zoological
specimen to know that if it is a crocodile, it can't be an alligator, even
though it might have many similar features.  There may be reptiles as yet
undiscovered, or there may be some in my database where I don't know a
priori which class they are in, but if I do know the class and it is one I
know is a particular kind of reptile, than it would sure be nice to help my
classified avoid stupid mistakes.  Thus, I'd like to say

:Alligator owl:disjointWith :Crocodile
:GilaMonster owl:disjointWith :Crocodile
:GilaMonster owl:disjointWith :Alligator
and etc -- pushing this example (and, by the way, it is one my group is
working on in a new project) we would like to use a classifier to classify
the reptiles in a large DB such as the one found at [2] -- problem is there

The following number of reptile classes represented in [2]

Amphisbaenia (amphisbaenians)   160
Sauria (lizards)   4675
Serpentes (snakes) 2940
Testudines (turtles) 302
Crocodylia (crocodiles) 23
Rhynchocephalia (tuataras) 2
Reptiles total 8101

So in OWL, we would need 18 different statements to differentiate the 6
classes, but we would need a total of well over 14,000,000 disjoint
statements if we really wanted to make these assertions explicitely  --
writing this down as 6 lists with 4675 clauses in one of the lists is bad
p.s. Note that in actual implementation we are using an extra-logical
mechanism to deal with the reasoning because adding the 14M assertions would
overwhelm any reasoner built to date -- but I think that is immaterial to
the matter at hand -- our database scraper would like to note that the
members of these classes are disjoint.

[1] http://lists.w3.org/Archives/Public/www-webont-wg/2003May/0206.html

[2] http://www.embl-heidelberg.de/~uetz/LivingReptiles.html

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 Tuesday, 15 July 2003 19:04:33 UTC

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