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Re: DAML-ONT: the case for closedness

From: Jeff Heflin <heflin@cs.umd.edu>
Date: Thu, 19 Oct 2000 13:24:26 -0400
Message-ID: <39EF2E4A.724B9ED@cs.umd.edu>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
CC: www-rdf-logic@w3.org
"Peter F. Patel-Schneider" wrote:
> 
> If some other modeller wants to augment the
> properties of a primitive class then I don't see why this should not be
> allowed.  Of course this other modeller can get into trouble by adding
> properties that should not be there, but I don't see that the goal of a
> modelling language is to prevent modellers from doing wrong things, nor
> do I see that there is any way of preventing such mistakes in any case,
> even if that was desired.
> 

True, there is no way to prevent modellers from doing wrong things, but
it would be nice if we could prevent one modeller from screwing up the
world for everyone else. We don't want some kid in the Phillipines to
create an ontology that breaks or changes the meaning of the globally
agreed to "E-commerce ontology," but if he needs to refine it to include
rules and definitions to describe some particularly innovative product
he's selling, then by all means we shouldn't restrict him. This is our
conundrum. We want to prohibit poor or worse yet, malicious extensions,
while allowing beneficial ones. Yet, how can a software agent determine
which category a particular ontology falls into? This is one of the
problems that I thinks makes KR on the Web more difficult and exciting
than traditional KR.

Jerome's idea of saying that a particular definition is "closed" is an
interesting one and might be useful in certain situations. However, I am
unsure how many definitions on the web can truly be closed. After all,
most logical theories are just approximations and there are often rules
that could be added to make the approximations more accurate. As a
result, you run the risk of people closing things that really shouldn't
be closed, which could lead to fragmentation as other people generate a
new term for the concept just so they can refine the definition in order
to get a better model of the world.

I think Pat has the right idea in wanting to integrate the ideas of
authorization and source into the semantic theory. BTW, Jim and I
described an initial approach to these problems in our paper "Dynamic
Ontologies on the Web" (see
http://www.cs.umd.edu/projects/plus/SHOE/pubs/aaai2000.pdf if
interested).

Jeff
Received on Thursday, 19 October 2000 13:24:28 GMT

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