Continuing our earlier discussion on the dimensions of ontology, do you
think there is a value in measuring "closed world" vs. "open world"
ontologies? (01)
If so, do you see commonality, in this dimension, between what Adrian is
trying to express, and the idea of having an intensional vs. an extensional
definition of the domain? (02)
Chuck (03)
ontolog-forum-bounces@xxxxxxxxxxxxxxxx wrote on 02/08/2007 01:22:11 PM: (04)
> Adrian Walker wrote:
>
> > Actually, if there is to be a new Wikipedia or other encyclopedia entry
on
> > logic for ontologies, it should summarize the ongoing debate between
the
> > "closed" and "open" world negationist camps.
>
> I would welcome that, but I wonder how many rounds it will take to get a
> version that is acceptable to most of the parties involved.
>
> It is my impression that there are at least 3 importantly different
models of
> the "closed world", and they probably relate to what kind of inferences
the
> "camp" wants to make. Further, there are several problems that
> arise when the
> closed worlders need to mix "closed" concepts and "open" concepts.
>
> One can, for certain "instantaneous" inferences, assume that the universe
is
> finite and consists only of things recorded in the current information
base.
> But to account for the evolution of that information base over time, one
> obviously cannot make that assumption. And one has to step very
carefully
> through the swamp that is created when these notions get mixed. That is
why,
> Michael Kifer, for example, says that all rules languages are programming (05)
> languages. They model a carefully chosen inferential procedure.
>
> As to Adrian's examples:
>
> > Almost all uses of databases
> > in our everyday life rely on things like "if it's not in the catalog we
> > don't stock it",
>
> This is probably a business rule. It is true because, like Jean-Luc
Picard,
> we "make it so".
>
> > "if no flight number to Podunk is in the database, then
> > there is no flight to Podunk"
>
> that we can do anything about.
>
> The speaker doesn't actually care whether there is a flight to Podunk; he
is
> focussing only on knowledge that affects HIS behavior. But knowledge
that
> does not affect his behavior might very well affect the behavior of
> some other
> person who has access to the same information.
>
> > so we should not ignore closed world
> > usage of
> > databases just because the clasical logicians never wrote about it.
>
> I'm not a crazy evangelist for monotonicity, either. I only point out
that
> closed world systems are designed for a particular purpose, and in
general,
> you cannot use them safely for inferencing for any other purpose.
>
> -Ed
>
> --
> Edward J. Barkmeyer Email: edbark@xxxxxxxx
> National Institute of Standards & Technology
> Manufacturing Systems Integration Division
> 100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
> Gaithersburg, MD 20899-8263 FAX: +1 301-975-4694
>
> "The opinions expressed above do not reflect consensus of NIST,
> and have not been reviewed by any Government authority." (06)
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