ONT Re: SUO: 21 May 2002 -- Unanswered Questions About SUMO Set Theory
I'm trying to send again in response to Bill's request
ASCII conventions. Sorry, if it still didn't work.
Mike
At 07:31 AM 6/2/2002 -0700, Erik Larson wrote:
>
> That is my lead-in to ontology considerations: build ontologies with
> solutions to problems in mind! If you already have an 'Ontology',
> reformulate it to cover a set of solutions important to your customers
(or to
> facilitate a set of apps you have or want to build).
>
> Practically speaking, this will mean at least two things:
>
> 1. Upper Ontology concepts are necessary (e.g., for partitioning categories
> of things: keeping disjoint categories disjoint, etc), but it's silly to
> spend a lot of effort writing axioms for high-level terms, since the rules
> will almost always have consequences that no one cares about, and even if
> they might in some cases, it's not as if you'll know what this value will be
> beforehand, and be able to pre-empt the process by making your terms and
> rules "up front." Also the terms themselves will tend to change as
different
> inference requirements change. Even if you can define a bunch of 'context'
> theories and cram terms into them to preserve local consistency,
> truth,relevance, etc, the way the contexts themselves have been chosen will
> also need to change as different problems are posed. This suggests a
> minimalist approach to upper ontological terms (for that matter, of
> ontologies generally)--the less "bloat" you can get by with, the better.
Hi Erik:
Your points here have given me a lot of pause for thought. I think that I
disagree a little bit with your ontology heuristics, here but let me try to
get
clearer on what you're claiming here and also try to give some general
indication of why I think I might disagree.
Regarding your point in (1), I'd like you to provide a bit more argument or
clarification here. If we think that a concept is important enough to include
in our upper ontology, why assume that its meaning isn't relevant enough to
bother to attempt to further articulate with axioms? You seem to have
acknowledged that subtyping and disjointness rules are important for upper
ontology concepts. How do you jump from the acknowledgement that the
conclusions from subtyping and disjointness rules will be entirely germane to
our applications to the assumption that rules that articulate any other
kind of
information are, as a default rule, useless? This isn't obvious to me.
>
> 2. Large chunks of ontological terms won't be reusable from domain to
domain,
> because they must be choosen to fit with axioms that are written to get a
set
> of specific derived consequences for end-users. This will naturally tend to
> make a vocabulary more specific to its uses. I've seen how this happens
> first-hand, in a prior engineering project where our team had, ostensibly,
> lots of concepts already asserted in the KB on our topic for us to use.
Once
> we clearly understood the problem-space however, it was obvious that we had
> to ignore large chunks of the pre-existing terms to make any progress. Even
> when we could partially salvage existing knowledge, it had to be re-written
> in a way that would facilitate the specific needs of our project, and this
> took practically as much time as creating everything afresh. (True, some of
> the upper ontology terms were more reusable, but also less relevant).
I'm not quite sure that I understand the first two sentences in section 2.
Regarding re-use, of course, you're correct that there is a lot of different
knowledge that will be germane to a domain and we shouldn't assume that rules
written for one facet of the domain will be reusable for reasoning about
another facet of the domain. If you give me a set of rules designed to reason
about automobile purchasing it's possible that it may not be very useful for
reasoning about automobile repair. I may have to write new rules for
reasoning
about automobile repair. This claims seems to be true and noncontroversial
but
is there more to it than this?
>
> In short (well, I guess I should say "in long" now), IMHO don't bother
> writing rules that just 'express knowledge', and don't bother creating (too
> many) terms with just that motivation either--at least not if you want to
> solve problems for Real People.
What is an upper ontology but something that "just expresses knowledge"? Are
you claiming that it is useful to write some rules that just express knowledge
and not others? Why is it useful to have subtyping and disjointness rules,
rules which certainly seem to just express knowledge, but no other rules?
Or do you actually have a more radical view? Do you think that each
application is so different from each other one that trying to find some
subsuming body of useful knowledge, an upper ontology, is pointless? I
disagree with this claim, just for the record, but I'd like to hear more
before
trying to persuade you if it is your own view. (I'm more sympathetic to the
claim that an upper ontology should be quite small but very well axiomatized.
Part of the reason I'd be more sympathetic is because it's conceivable that
human intelligence is like this, i.e., based on a relatively small number of
very well understood concepts. It's hard, however, to imagine generating
anything resembling intelligence, i.e., an ability to generate solutions to
problems, if a system has very little understanding of *any* upper ontology
concept.)
By the way, please tell me who these Real People are and please let me now
how
I can attain such enhanced metaphysical status if I don't already have it.
best,
Mike Pool
>
> -Erik
>
>
>
>
>
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________________________________
Mike Pool
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