[net.ai] taxonomizing in AI: useless, harmful

marek@iuvax.UUCP (02/10/86)

> [Stan Shebs:] In article <3600036@iuvax.UUCP> marek@iuvax.UUCP writes:
>  ...one of the most misguided AI efforts to date is 
>  taxonomizing a la Michalski et al: setting up categories along arbitrary 
>  lines dictated by somebody or other's intuition.  If AI does not have 
>  the mechanism-cum-explanation to describe a phenomenon, what right does it 
>  have to a) taxonomize it and b) demand that its taxonomizing be recognized 
>  as an achievement?  
> 
> I assume you have something wonderful that we haven't heard about?

I assume that you are intentionally jesting, equating that which I criticize
with all that AI has to offer.  Taxonomizing is a debatable art of empirical
science, usually justified when a scientist finds itself overwhelmed with
gobs and gobs of identifiable specimens, e.g. entymology.  But AI is not
overwhelmed by gobs and gobs of tangible singulars; it is a constructive
endeavor that puts up putatative mechanisms to be replaced by others.  The
kinds of learning Michalski so effortlessly plucks out of the thin air are not
as incontrovertibly real and graspable as instances of dead bugs.

One could argue, I suppose, that taxonomizing in absence of multitudes of
real specimens is a harmless way of pursuing tenure, but I argue in
Indiana U. Computer Science Technical Report No. 176, "Why Artificial
Intelligence is Necessarily Ad Hoc: Your Thinking/Approach/Model/Solution
Rides on Your Metaphors", that it causes grave harm to the field.  E-mail
nlg@iuvax.uucp for a copy, or write to Nancy Garrett at Computer Science
Department, Lindley Hall 101, Indiana University, Bloomington, Indiana
47406.

> Or do you believe that because there are unsolved problems in physics,
> chemists and biologists have no right to study objects whose behavior is
> ultimately described in terms of physics?
> 
> 							stan shebs
> 							(shebs@utah-orion)

TR #176 also happens to touch on the issue of how ill-formed Stan Shebs's
rhetorical question is and how this sort of analogizing has gotten AI into
its current (sad) shape.

Please consider whether taxonomizing kinds of learning from the AI perspective
in 1981 is at all analogous to chemists' and biologists' "right to study the
objects whose behavior is ultimately described in terms of physics."  If so,
when is the last time you saw a biology/chemistry text titled "Cellular
Resonance" in which 3 authors offered an exhaustive table of carcinogenic
vibrations, offered as a collection of current papers in oncology?...

More constructively, I am in the process of developing an abstract machine.
I think that developing abstract machines is more in the line of my work as
an AI worker than postulating arbitrary taxonomies where there's neither need
for them nor raw material.

				-- Marek Lugowski

shebs@utah-cs.UUCP (Stanley Shebs) (02/12/86)

In article <3600038@iuvax.UUCP> marek@iuvax.UUCP writes:

>... Taxonomizing is a debatable art of empirical
>science, usually justified when a scientist finds itself overwhelmed with
>gobs and gobs of identifiable specimens, e.g. entymology.  But AI is not
>overwhelmed by gobs and gobs of tangible singulars; it is a constructive
>endeavor that puts up putatative mechanisms to be replaced by others.  The
>kinds of learning Michalski so effortlessly plucks out of the thin air are not
>as incontrovertibly real and graspable as instances of dead bugs.

Now I'm confused!  Were you criticizing Michalski et al's taxonomy of
learning techniques in pp. 7-13 of "Machine Learning", or the "conceptual
clustering" work that he has done?  I think both are valid - the first
is basically a reader's guide to help sort out the strengths and limitations
of dozens of different lines of research.  I certainly doubt (and hope)
no one takes that sort of thing as gospel.

For those folks not familiar with conceptual clustering, I can characterize
it as an outgrowth of statistical clustering methods, but which uses a
sort of Occam's razor heuristic to decide what the valid clusters are.
That is, conceptual "simplicity" dictates where the clusters lie.  As an
example, consider a collection of data points which lie on several
intersecting lines.  If the data points you have come in bunches at
certain places along the lines, statistical analysis will fail dramatically;
it will see the bunches and miss the lines.  Conceptual clustering will
find the lines, because they are a better explanation conceptually than are
random bunches.  (In reality, clustering happens on logical terms in
a form of truth table; I don't think they've tried to supplant statisticians
yet!)

>Please consider whether taxonomizing kinds of learning from the AI perspective
>in 1981 is at all analogous to chemists' and biologists' "right to study the
>objects whose behavior is ultimately described in terms of physics."  If so,
>when is the last time you saw a biology/chemistry text titled "Cellular
>Resonance" in which 3 authors offered an exhaustive table of carcinogenic
>vibrations, offered as a collection of current papers in oncology?...

Hmmm, this does sound like a veiled reference to "Machine Learning"!
Personally, I prefer a collection of different viewpoints over someone's
densely written tome on the ultimate answer to all the problems of AI...

>More constructively, I am in the process of developing an abstract machine.
>I think that developing abstract machines is more in the line of my work as
>an AI worker than postulating arbitrary taxonomies where there's neither need
>for them nor raw material.
>
>				-- Marek Lugowski

I detect a hint of a suggestion that "abstract machines" are Very Important
Work in AI.  I am perhaps defensive about taxonomies because part of my
own work involves taxonomies of programming languages and implementations,
not as an end in itself, but as a route to understanding.  And of course
it's also Very Important Work... :-)

							stan shebs

tgd@orstcs.UUCP (tgd) (02/19/86)

Taxonomic reasoning is a weak, but important form of plausible reasoning.
It makes no difference whether it is applied to man-made or naturally
occurring phenomena.  The debate on the status of artificial intelligence
programs (and methods) as objects for empirical study has been going on
since the field began.  I assume you are familiar with the arguments put
forth by Simon in his book Sciences of the Artificial.  Consider the case of
the steam engine and the rise of thermodynamics.  After many failed attempts
to improve the efficiency of the steam engine, people began to look for 
an explanation, and the result is one of the deepest theories of modern
science.  

I hope that a similar process is occurring in artificial intelligence.  By
analyzing our failures and successes, we can attempt to find a deeper theory
that explains them.  The efforts by Michalski and others (including myself)
to develop a taxonomy of machine learning programs is viewed by me, at
least, not as an end in itself, but as a first step toward understanding the
machine learning problem at a deeper level. 

Tom Dietterich
Department of Computer Science
Oregon State University
Corvallis, OR 97331
dietterich@oregon-state.csnet