[From Bill Powers (971204.1611 MST)]
Mary said I should send to the net some of a post to Tim Carey, so here it
is ["MOL" means "method of levels"]:
When you're working from a theory that makes definite predictions, there's a
great danger of seeing all behavior through theory-colored glasses, so no
matter what happens, you can see it as fitting the theory. I fight that all
the time in myself. This is what the argument about "incentive" and such
stuff is concerned with, although the people who support those notions don't
realize it. Sure, if you believe that incentives and rewards lead people to
do things, or "set the occasion" for their behavior, you can watcb what
happens and by golly you can really SEE those effects. The problem is that
you're NOT seeing them -- you're imagining them. Once you have a theoretical
interpretation, it's just damned hard to believe that you're forcing the
world to look the way you expect it to look.
Exactly the same thing holds for PCT or any of the ideas attached to it, like
MOL. People blithely talk about perceptions and error signals and output
functions, and forget that all they can really SEE is people doing things in
an environment. They can't see another person's perceptions or reference
signals or error signals, or any of the functions we postulate inside the
control system. What we're doing is imagining that behind what we actually
observe is this theoretical structure. This imagination can get so vivid that
we think we are actually observing these things, so the theory starts to get
more real than direct experience (that happened a long time ago in physics).
To me, science is all about distinguishing observation from imagination, and
always trying to keep the difference in mind (sometimes in vain, of course).
To me, a real scientist is a person who does an experiment and finds that his
predictions are completely and exactly matched by the results, and
immediately says "Wait a minute, something must be wrong here." After all,
the theory is a figment of the imagination -- it's so easy to be seduced by a
theory that one just has to be suspicious that the results were somehow
cooked up or influenced by expectations. It's only when every possible flaw
in the experiment has been ruled out that a scientist is finally backed into
a corner from which he can't escape: "I guess the damned thing must be right."
This is why I don't feel apologetic about our simple computer experiments in
which people control simple experiences. Those experiments are SOLID. They
show exactly what the theory predicts. Try as I might, I can't find any other
explanation for how these people can be doing what they're doing. Oh, I know
that the detailed model we use is probably too simple and that there might be
dozen physical arrangements that would do the same thing. But I don't know
of any other theoretical model that comes within a mile of predicting what we
see correctly. If I hadn't tried so hard to think of other explanations I
wouldn't be nearly as impressed.
This is why I sometimes seem to have an answer for everything. I've really
thought about nearly every question anyone raises, not because I have
developed such a strong belief in PCT but because I've been so unsure and
doubtful about it. I doubt that anyone can come up with a criticism of PCT
that I didn't come up with myself long ago.
The more skeptical you are, the more aware you are of what you can and can't
observe, the more clearly you will understand the difference between theory
and fact. And paradoxically, the more confidence you will build in your
ability to evaluate a theory and its predictions. I have a lot of confidence
in PCT precisely because I have tried to face every way in which it could be
wrong, every way I could be fooling myself. By this time, I know what is
imaginary about it, and what is real about the observations.
There's a helpful exercise I go through from time to time. I say to myself,
"OK, PCT is just another figment of my imagination. So let's forget about it,
and try to figure out how I fooled myself into believing it. What on earth
ever made me think that people are control systems?" And I then rebuild the
whole theory from scratch, starting with wiggling my fingers while I look at
them, or playing with some rubber bands. Then I realize that the evidence is
absolutely everywhere, in every little thing I do, and that I really, truly,
can't think of any other way to explain it all. Maybe someone else could, but
I can't. So then I'm good for another month or two.
Bill
