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Posted-Date: Tue, 15 Dec 92 20:14:47 PST
Newsgroups: bit.listserv.csg-l
Date:         Tue, 15 Dec 1992 20:14:47 PST
From:         marken@AERO.ORG
Subject:      Presenting PCT

[From Rick Marken (921215.2000)]

Avery.Andrews (921216.09109) --

>  If someone accepts (a) that they don't understand
>feedback as well as they thought they dud (b) feedback mechanisms are
>much more central in the organization of behavior than is generally
>supposed, the rest follows.  E.g. that it's a significant achievment
>to predict tracking behavior for one whole minute, that we ought
>to try to find out what Aplysia is controlling for, etc.

Yes. This is a good idea. And your earlier suggestion that we develop
models (like the "Little Man") that show the capabilities of the
control architecture is also good. I didn't mean to jump on it
so negatively. But your comments (even though I misinterpreted them)
did jog a good thought; one of our problems in PCT is that we can
rarely go to the research results in the literature and say "we
have a model that can account for your results better than any other
model". This is because most results in the literature are statistical;
yet they are quoted as fact. Just after my "Blind men" paper was
rejected there was a paper posted through Psycholoquy -- I guess it's
the one that was accepted. Unfortunately I did not save it (bad sport
that I am) but it was on sentence comprehension or something. Well the
article sounded really interesting, deeply cognitive -- about how
inferences were drawn from sentences and all. Well, it turns out
that they actually described an experiment to test their little theory
(it was not really a working model). Guess what. Two groups of subjects
read sentences -- and there was some independent variable manipulated
(the taregt of the inference or something) at two levels -- conditions
A & B. I can't rememebr the details -- all I remember are the results which
were something like "as expected, condition A did significantly better
than B (t= 2.36, df=23, p<.05). Well, we know that means that a slight
majority of people in A did as expected -- but a lot of people in A
did what people in B did and vice versa. But the conclusion that
will live on (and be the target of theory) will be that A leads to
significantly more of the behavior (whatever it is) than B. There is
just nothing for PCT to do with this kind of data. PCT is a working
model of "one organism at a time" and we expect matches between model
and data that are extremely accurate -- or we go back to the drawing
board. We'd be at the drawing board night after night if we used
PCT to try to predict this kind of noise.

The more one understands feedback control, the less one sees in
the psycholgical research literature that tests that understanding.
Ultimately, you realize that PCT is designed to exlain control --
and you can't explain control until you know that it is happening.
None of the existent research in psychology provides any evidence
that control is happening in a particular situation -- or of what
is being controlled.  The inescabale conclusion is that we must start
the whole enterprose of psychology all over again -- with the
understanding that organisms are locked in a negative feedback
situation with respect to their environment -- ie. they control.

But we can build snazzy models in the meantime too.

Best

Rick
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