Re: A simplistic definition of "ontology"

phayes@ai.uiuc.edu (Pat Hayes)
Message-id: <199510042044.AA08508@a.cs.uiuc.edu>
X-Sender: phayes@tubman.cs.uiuc.edu
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Date: Wed, 4 Oct 1995 15:59:44 -0600
To: hovy@isi.edu (Eduard Hovy), srkb@cs.umbc.edu
From: phayes@ai.uiuc.edu (Pat Hayes)
Subject: Re: A simplistic definition of "ontology"
Sender: owner-srkb@cs.umbc.edu
Precedence: bulk
At  8:41 AM 10/4/95 -0500, Eduard Hovy wrote:
>Just to stir up some blood: 

We havn't quite got to THAT stage yet, at least not out here in the midwest.

>  An ontology is a collection of symbols that represent (i.e., name) some 
>  set of phenomena in the "external world" within a computer (or possibly 
>  within other, non-implemented, systems, although who knows what that 
>  would be interesting for).  Typically, the phenomena include objects 
>  and processes and states, and typically, these entities are related 
>  among themselves; usually, the ontology names (some of) these relations.  
>

I think the issue can be focussed by asking whether it is enough to simply
*name* the relations, or should we ask an ontology to somehow *specify*
them. Can the ontology rely on the knowledge of the reader to interpret
what its symbols mean, or should we think of it rather as a vehicle for
representing the knowledge that human users use to do that very
interpreting? I think this tension has been in the ontology community since
the beginning. Coming as I do from the 'knowledge representation' (rather
than the 'glossary') side of the divide, I always wonder just how far away
the other side can be taken to be. My comment which started this exchange
wasnt really asking for a definition (maybe its impossible to give a
*definition* of an ontology which will satisfy everyone) but raising a
doubt, or a question, about whether it is useful to talk of a mere glossary
as being an ontology. Or, to put it another way; if an ontology has no
axioms in it at all, what do we gain by calling it an ontology?

(One obvious answer might be that such a glossary is a useful step along
the way to creating a true ontology, a kind of ontology-sketch, but I dont
think that is how the compilers of such glossaries regard them.)

Pat

------------------------------------------------------------------------------
Beckman Institute                                      (217)244 1616 office
405 North Mathews Avenue              (415)855 9043 or (217)328 3947 home
Urbana, Il.  61801                                     (217)244 8371 fax

Phayes@cs.uiuc.edu