Re: Ontological EDI & Wittgenstein (Fritz Lehmann)
Date: Wed, 28 Sep 94 22:24:51 CDT
From: (Fritz Lehmann)
Message-id: <>
Subject: Re: Ontological EDI & Wittgenstein
Precedence: bulk

     Scott Dickson of Ontek, Inc. responded to my recent 
"ontological EDI" posting, and as usual I agree with
his cautionary words.

    One point deserves explaining.  He said among other things:
----begin quote----
Fritz Lehman wrote (regarding classification and constraints):
>And we can agree completely that no barge (X12
>Element 211:BRG) is a suburb, despite the natural imprecision of both
I would not agree with such a statement.  I recall designs by the architect
Paolo Soleri of floating self-contained cities, or arcologies.  One could
easily imagine tethered floating suburbs, which one could easily classify
as large barges.
This observation is not as whimsical as it seems.  It illustrates a basic
difference between real-world classification schemes implemented in humans
and abstract classification schemes encoded in logic.  A better expression
of the _real_ "constraint" is "a barge is usually not a suburb" or maybe "a
barge is almost always not a suburb".  Of course, we humans almost
certainly don't have such a "constraint" as part of the mental processes
that recognize barges and suburbs.  We only construct such a "constraint"
when we want to give an example of a "constraint" of this kind.
----end quote----

     Yeah, I thought about possible exceptions to the  mutual
exclusion of BARGE and SUBURB; that's why I said "we can agree
completely that  no barge ... is a suburb"  rather than "No
barge can be a suburb."   Practical business transactions
have an advantage in that they deal with the world as it is.
They have that "common ground", and they don't have to be
concerned about science-fiction worlds, etc.  I could have
said "No barge is a Social Security Number" -- I just
happened to write down the BARGE (as measurement unit) code
from the X12 standard in my notes.  In fact, I think it might be
universally true that "No barge is a suburb" in the intended
(undefined of course!) EDI X12 sense, even in hypothetical
worlds.  A named suburb might be _made_ of a barge or several
barges, but it _is_ not a barge (especially as an X12 211
measurement unit!).  I'm all for making fine distinctions,
but this particular caveat of Scott's would be cured, I
think, by the very ontology that we are recommending.
A part of town could NOT be a physical measurement unit.
With "ontological EDI", the _computer_ would know this, not
just the human users.

                          Yours truly,   Fritz Lehmann
GRANDAI Software, 4282 Sandburg Way, Irvine, CA 92715, U.S.A.
Tel:(714)-733-0566  Fax:(714)-733-0506