Subject:
SUO: Re: General Design
From:
"John F. Sowa" <sowa@bestweb.net>
Date:
Tue, 12 Aug 2003 10:01:20 -0400
To:
"West, Matthew R SITI-ITPSIE" <matthew.west@shell.com>
CC:
Jon Awbrey <jawbrey@att.net>, Kenneth Fields <ken@create.ucsb.edu>, Ontology <ontology@ieee.org>, protege-discussion@SMI.Stanford.EDU, SUO <standard-upper-ontology@ieee.org>, cg@cs.uah.edu


Dear Matthew,

Thank you for the support.  I have been arguing for
as long as the SUO list existed that every engineering
project (including knowledge engineering) makes
abstractions from reality that omit seemingly
"irrelevant" details.  But what is irrelevant for
one project is often the central core of some
other project.

I certainly agree with people like Adam, Doug, and
Nicola that axioms are essential for detailed reasoning.
But in the early stages of any design -- and in any
stage of communication between independent projects --
conflicts in the assumptions (i.e., the axioms) are
the major obstacle.  And you simply *cannot* solve
that problem by forcing people to adopt axioms that
weren't designed for their purpose.

Of all the axioms that have been proposed, the
axioms of mereology are the worst offenders.
I consider mereology to be a useful approximation
for many purposes, but those axioms are *always*
approximations that are simply false at the level
of atoms and molecules (and even at the level of
bacteria, dust, surface grime, and cat hairs).

That is why I consider any ontology with lots of
formally defined axioms -- including Cyc, Sumo,
and Dolce -- to be at best a useful approximation
for some purposes, and at worst a disaster waiting
to happen for other purposes.

That doesn't mean that we have to throw away all the
work that went into writing the axioms of Cyc, Sumo,
and Dolce.  But what we must do is to develop means
of modularizing them and, for any given purpose,
extracting, combining, and revising whatever modules
are appropriate.

John

PS:  Note how many times the word "purpose" occurs in
the above paragraphs.  Some people have been trying to
eliminate the idea of "purpose" from their ontologies.
That attempt is guaranteed to make their work useless
for *every* purpose.
_____________________________________________________

West, Matthew R SITI-ITPSIE wrote:

> Dear John,
>
> A word of support.
>
>> Of course, not.  The main reason why WordNet is more flexible than
>> Cyc, Sumo, Dolce, or any other axiomatized ontology is simple;
>>
>>     The axioms get in the way.
>
>
> I have spent many years trying to improve the quality of data models
> in Shell and elsewhere. By far the biggest problem has been that data models impose constraints that simply aren't true (except in
> some limited set of circumstances). As a result I have become very
> conservative about constraints or axioms.
>
> Matthew West
> Principal Consultant
> Shell Information Technology International Limited
> Shell Centre, London SE1 7NA, United Kingdom
>
> Tel: +44 20 7934 4490 Other Tel: +44 7796 336538
> Email: matthew.west@shell.com
> Internet: http://www.shell.com