Re: SUO: Re: Focus and Volume
>Pat,
> It would be incorrect to place me at the opposite end of the
>spectrum from Doug. I'd summarize his position as that an upper
>ontology is essential and relevant
The last time I met Doug (about 6 months ago) I talked to him about
the SUO, briefly. I asked him whether it wouldnt make sense to simply
remove the 'upper ontology' from CYC altogether, and have an
inheritance hierarchy which simply had a large number of top nodes
(which would be, roughly, the tips of the upper ontology
classification.) He agreed, and said that he had in fact seriously
suggested making that change some years earlier, but that his
customer base all protested that they preferred to have a single top
node. He shrugged, with the implication that if thats what they want,
he was willing to let them keep it. So I think that your and Doug's
viewpoints are not quite identical; he thinks the upper levels of the
ontology are irrelevant and distracting.
But let me be the straw man. I will stake out a position and defend
it: the upper ontology is not irrelevant, but almost any upper
ontology does more harm than good. That is, almost any ontology could
be constructed more efficiently and with less work, if the highest
levels were stripped out or ignored, and then perhaps inserted after
the fact to 'fit' the middle-level concepts. The reason being that it
is essentially impossible to think of the necessary distinctions ab
initio, but that one must discover them by building nontrivial
axiomatic theories at the 'middle' levels first, and thereby
discovering the conceptual distinctions that provide the best
representational leverage. Most of the high-level debates on this
list that have been of real ontological substance (eg the
continuant/occurrent debate, the relevance of 4-d spatiotemporal
frameworks) have been on issues that have already been distilled from
earlier middle-level work (in that case, an entire literature), and
most of those that have not been so distilled (eg almost everything
that is in any way associated with the intials CSP) have been an
entire waste of time and bandwidth. Meanwhile, the merged ontology
consists of an accumulation of middle-level theories being hung onto
a framework which was provided a priori rather than being abstracted
from the theories themselves (in direct opposition to the methodology
of the author of that heirarchy, by the way) and shows the resultant
conceptual strain at almost every point.
I might add that this methodology is supported to some extent by
empirical work on concept mining, where a key strategy in identifying
useful conceptual dimensions is to find the ways that concepts can be
teased apart, ie how they differ as well as the ways they are
similar. The key question to ask is, given three concepts A, B and C:
in what way would B be closest to A and furthest from C? The point
being that this kind of analysis requires a level of detail which
only becomes apparent when one has a reasonable amount of particular
detailed knowledge to apply it to.
> but that there are many "good enough" upper ontologies that one
>might construct and all would be equally useful.
Well, in the sense that zero utility is equally useful as zero, I
guess that you and Doug might agree.
> The point is to pick one (or generate one) and move on, as
>agonizing over the "one true ontology" is pointless. I agree with
>Doug whole-heartedly.
No, the point is to move on. The issue is not the one true ontology,
but the utility of ANY upper ontology. If the upper ontology is
really not that important, then why are we (you) wasting so much
time building one? What utility is shared by *all* upper ontologies?
Look, to make the point more, er, pointedly. Here is a proposal for
an upper ontology. It is a tree with two levels. The root is called
"entity", and its children are all the middle-level concepts that
anyone wants to use. To add a new such concept is easy: it is simply
a sibling of all the others. Call this the SHUO, the SHallow Upper
Ontology. Lets take that as a starting point and at some point, when
we have a reasonably large SHUO, try applying the techniques outlined
on Sowa's website to infer a suitable lattice-ised version of it.
Now, that might be some actual use. Even for those who feel that a
philosophical perspective should provide some useful structure for an
UO, this would be an interesting experiment. If the automatic
techniques rediscover some well-known philosphical distinction, they
can claim some empirical success. If they do not, some may feel that
this is a diagnostic for more axiomatic work to be done, while others
may feel that their disdain for mere philosophizing has been
vindicated. But the result is more likely to be useful, and is MUCH
less likely to be contentious, in either case. We could make a
SHUO-ish version of the merged ontology just by stripping out all the
upper levels, by the way.
Pat
>
>At 07:07 PM 5/14/2001 -0500, pat hayes wrote:
>
>>>Jon Awbrey wrote:
>>> > .......
>>>........
>>>......
>>>......
>>>.......
>>>........
>>>.........
>>> >
>>> > 3. Square One is that everybody who makes a contribution to the
>>> > main list probably does so because they honestly believe that
>>> > it has a bearing on what a State of the Art Third Millennium
>>> > Ontology System ought to look like, even if that makes some
>>> > State of the Art 1979 folks uncomfortable with the amount of
>>> > work and the number of different expertises that would really
>>> > be required to avoid cranking out yet another standard that
>>> > all innovative people will have to work against from Day One.
>>>
>>>
>>>There's a spectrum of views on
>>>the extent to which the SUO should be
>>>pushing the state of the art as opposed to more simply
>>>reflecting current accepted/best practice.
>>
>>It isnt clear to me that there really IS a currently accepted or
>>best practice in this area. We would do well to remember that there
>>really are only a few upper ontologies in existence, and many of
>>their authors are contributors to this list (and the other major
>>author, Doug Lenat, is firmly of the opinion that the upper levels
>>of a large-scale ontology are largely irrelevant.)
>>
>>>In my opinion, a shared statement on where we are along this spectrum
>>>would give us a metric which would identify a good fraction of all
>>>previously posted paragraphs as not relevant (to the group per se).
>>
>>I would suggest that a more useful spectrum along which to place
>>opinions would be the one that has Doug at one end and probably
>>Adam at the other, which estimates the likely relevance of upper
>>levels of the ontology to anything said at lower levels. Doug's
>>view, if I can capture it well enough in a brief sentence, is that
>>the inheritance structure of any ontology only becomes important
>>when the density of axioms becomes reasonably high, since until
>>there are significant numbers of things to say that are likely to
>>be usefully inherited downwards, the heirarchy is really no more
>>than decoration. Put into less contentious and more functional
>>terms, this might be paraphrased as the methodological requirement
>>that any high-level distinction be justified in terms of some
>>assertions that are likely to have inheritable downward
>>consequences, ie that something useful can be inferred about some
>>thing or category X by virtue of it being placed under the
>>high-level category. Doug's opinion can then be derived from his
>>extensive experience as the observation that very little can be
>>usefully said at the very high levels which is likely to have any
>>useful consequences at any lower levels, that could not be said
>>better or more easily at those lower levels directly.
>>The other end of this opinion spectrum holds that getting the upper
>>levels 'right' in some sense (there may be several senses involved,
>>by the way) is a prerequisite, or at any rate a desideratum, for
>>creating an ontology with well-structured lower levels. This is the
>>more popular opinion - some seem to take it as almost axiomatic -
>>but it seems to me that this case is the harder one to make, if a
>>case needs to be made. I would suggest that a more useful and
>>productive debating topic than the ones that have been cluttering
>>this list so far might arise if those who feel that an upper
>>ontology is obviously useful, could provide arguments for this
>>position. At the very least, this would be a start at exposing the
>>various assumptions and goals that drive the SUO effort, and might
>>help to clarify how these various opinions relate to each other.
>>Since we often seem to be trying to pull the effort in different
>>directions, this might be worth taking a little time over.
>>
>>Pat Hayes
>>
>>---------------------------------------------------------------------
>>IHMC (850)434 8903 home
>>40 South Alcaniz St. (850)202 4416 office
>>Pensacola, FL 32501 (850)202 4440 fax
>>phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
>
>Adam Pease
>Teknowledge
>(650) 424-0500 x571
---------------------------------------------------------------------
IHMC (850)434 8903 home
40 South Alcaniz St. (850)202 4416 office
Pensacola, FL 32501 (850)202 4440 fax
phayes@ai.uwf.edu
http://www.coginst.uwf.edu/~phayes