an example ontology

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From: davis@ai.mit.edu (Randall Davis)
Date: Mon, 24 Aug 92 18:28:06 edt
Message-id: <9208242228.AA06792@hatcher.ai.mit.edu>
To: Gruber@sumex-aim.stanford.edu
Cc: srkb@ISI.EDU
In-reply-to: Tom Gruber's message of Wed, 12 Aug 92  02:32:03 PDT <2922600723-1933131@KSL-Mac-69>
Subject: an example ontology

I think the idea of exploring out many of these issues with a real example is
a fine idea.  One small but I think important caution: don't write the
ontology that you can, write the one that captures the real world.  A few
examples:

(define-function PERSON.NAME (?person) :-> ?name
  "The name that people use as authors of publications.  One name per
   person."

Stephen King and Samuel Clemens are both going to be problematic.  And what
about anonymous works (eg, the bible)?


(define-class AUTHOR (?x)
  "An author is a person who writes things.  An author must have a name."

And committees?  How about committees with pseudonyms (eg, the Bourbaki, who
wrote a well known set of elementary mathematics texts)?

(Or are document authors allow to be any agent?  Not clear from a quick scan
of the defns.)


(define-class PUBLISHER (?x)
  "A publisher is an organization that publishes."

And individuals who publish?


(define-class UNIVERSITY (?x)
  "A university is an institute of higher learning that offers a
graduate research program.  Of importance here is the fact that
universities sponsor the publication of dissertations."

Dartmouth College (and a famous Supreme Court case from the mid 1800's) agree
that the institution is a college, not a University, yet it has a grad
research program, pubishes dissertations, etc.

+++++++++++++

It's easy to generate a lot of these by being nitpicking; that's not my intent
here.

The main point is that there is a significant amount of genuine complexity in
the world, complexity of the form that confounds attempts to write neat
definitions and universally quantified rules.  We ignore that complexity at
our peril.

One manifestation of taking this complexity seriously might be the desire to
be able to say something like ``the author(s) of a document are *typically*
one or more humans,'' ``most authors have one name,'' etc.

An ontology that ignored that (and other) real complexity in authorship,
publication, etc., would be an interesting exercise perhaps, but it would be
an exercise in describing bibliographies-as-they-ought-to-be-in-order-to-make-
their-descriptions-simple.  I think it's crucial in this undertaking to
describe the world as it is, which includes bibliographies-as-they-are-with-the-
details-that-drive-librarians-(and-sometimes-the-rest-of-us)-to-distraction.

It's absolutely crucial: otherwise this is an exercise in the definitions we
can write, not a exercise in finding out what we need to say; an exercise in
what our current KR languages permit or make easy, not an exercise in finding
out what we need to say.  Knowledge representation needs to be about the
world, and the world as it is, not as we wish it would be.