[From Bill Powers (960607.0600 MDT)]
Jeff Vancouver 960606.12:30 EST --
RE: first question
This is a nice example of a positive feedback loop in a results
(system dynamic's) model. It is also an example of several
negative feedback loops in a control theory sense, although, these
can only be speculations. ... I could do this with every one of
your questions, but I think you get the point.
Good, an extra-credit answer. I do get the point, which is that your
understanding of the control model goes past the words you happened to
use in the post that made me wonder.
Assuming that a person wants to achieve/maintain a goal (usually a
performance goal provided by some organization/researcher), the
output function must be organized such that the person can reduce
an error. Over the long run, for any system in the perceptual
hierarchy (not the intrinsic one), information about the state of
the environmental variable will have different influences on the
control system. Once a control system is established and well-
functioning (unlike John's above) information that indicates a
disturbance, results in an error which is corrected by some
behavior(s).
I think it will pay to maintain a clear distinction between learning and
performance. Learning is a control process of a _different kind_ from
the control process that is learned. The underlying goal of learning, I
suggest, is not the same as the goal of the process that is learned.
As a simple example, consider a rat learning to press a lever to obtain
food pellets. The rat would have no natural interest in making little
brown objects rattle into a dish. The hunger does not represent a
deficiency in food pellets; it represents an error in some critical
internal state, for example a state of fullness or of the available
energy levels. The rat is not trying to learn how to obtain food
pellets; the error that motivates the learning is not specific to food
pellets. ANYTHING that resulted in reduction of the fullness or
nutritional state error would be learned (if possible). To say that the
naive rat is learning how to obtain food pellets is to imply that the
rat already knows that if it could make those little brown things appear
in the food cup, it could reduce the (for short) hunger error.
As Hugh Petrie pointed out (1981, _The dilemma of enquiry and learning_,
U. of Chicago Press), learning involves the Meno Paradox of Socrates.
Socrates said to Meno
You argue that a man cannot enquire either about that which he
knows or about that which he does not know; for if he knows, he has
no need to enquire, and if not, he cannot; for he does not know the
very subject about which he is to enquire.
What the rat already knows it does not have to learn. If the rat has
already had experience with food pellets, then the goal of learning
could be said to involve learning how to find food pellets. But then
what is learned would not be that getting food pellets would help
assuage hunger, but that performing a specific kind of act would cause
food pellets to appear. The rat does not know in advance what act will
produce food pellets; it must be able to try different acts until it
sorts out which acts (if any) produce food pellets and which do not. The
reason that learning is needed is that the rat does not know what act
will have the desired result. Thus when we say that the rat is learning
the acts necessary to produce food pellets, we imply a contradiction:
that the rat already knows what acts it must learn to perform, and yet
is trying to learn them.
Consider all this in the context of your comment:
On the other hand, when the system is not well-functioning (e.g.
novel task). That is, outputs do not reduce error, reorganization
must take place. In this case information that some behavior
resulted in a reduction in error would, I hypothesis and model,
result in halting or at least slowing down reorganization such that
the output function holds the values that "work." Information that
results in a reduction in error is what you (and me) would call
negative feedback, but if that information comes from an external
agent, it is called positive feedback in our literature (because
the agent is able to say "yes, that's it" or something
like that).
What you seem to be saying here is that some error exists, but in the
case of interest that the system has no way of knowing that the error
has been reduced until told by an external agent. This implies that the
error is not an error between the learning system's own perceptions and
its own goals, but something existing in its environment. Only in that
way could an external agent know that there has or has not been a
reduction in error, while the acting system does not know. In fact, what
you are describing is control organized around an error that the
external agent experiences. In other words, it is the external agent
that is learning what to tell the acting system in order to control the
external agent's perceptions.
I think we need to be careful when using the term "reorganization." What
we commonly call learning does not always entail reorganization.
Suppose you're the one who is learning. You would like to make money,
and you do not have as much money as you want (both being prerequisites
to what follows). You are told that if you press the correct lever, you
will get $100, but if you press the wrong one you get nothing. In either
case, you get only one try. Since there are only two levers, what is to
be learned (which lever to press) is trivially simple, yet you can't be
sure of learning it correctly.
If an external agent informs you that lever A will produce the money,
your problem is solved: you press lever A, and get the money. I think
this is more or less the scenario you are thinking of.
But is this learning? Here the only thing that prevents you from
producing the right act is a lack of information about the effects of
the two levers. When the missing information is provided, learning is
instantly complete (if you believe it, and it is right). In fact, you
didn't have to learn HOW to do any act you didn't already know how to
do. No reorganization was involved.
So when would reorganization be involved? Suppose the two levers were
marked with symbols: a circle and a plus mark. The external observer
says "Pressing the time-out symbol will produce the money." This is like
a certain word-processor manual, which says "Press the Help key to get
context-sensitive help." The problem is, there is no help key on a
standard keyboard; the help key is actually (as a search through the
manual eventually shows) labeled "F1". So being told to press the time-
out symbol to get the money is of no use at all because you don't know
whether the circle or the plus mark is called the time-out symbol. Now,
if it were possible, you would have to reorganize to solve the problem
-- start pressing levers at random until the money appeared, and
discover for yourself how to correct the error. Of course under the
rules as stated you'd have only one try, and a 50% chance of getting the
money.
Thus, I am trying to show how, why and when positive and negative
feedback (in psychology's use of the terms) is useful using a
negative feedback model of behavior (perception control).
That's a worthy objective, but considering the nuances above, it may be
that the psychological use of these terms rests on a rather sketchy
analysis of the phenomenon to be explained. And anyway, I still feel
that there's a certain legitimacy in saying that positive and negative
feedback already had specific technical meanings before the terms were
picked up by psychologists, and that to alter those meanings arbitrarily
is an unwise and unfriendly act. Put the shoe on the other foot: What if
I had decided that "motivation" was to mean an action that causes
something to move? Don't you think that psychologists might have
objected to this usurpation of one of their favorite words to mean
something that is not at all what they intended the word to mean? And
wouldn't we have a terrible problem in communication if both camps
continued to use the word as they define it, without regard for its
meanings to the other side?
"The rat motivated the lever to produce food." That's roughly how "the
teacher provided positive feedback to the student" sounds to me.
···
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Rick Marken (960606.1030) --
Your answers to how PCT might be applied to masochistic Red Sox fans
were more useful than mine, and also far more interesting.
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Bruce Gregory (960606.1325 EDT) --
If the control theory dilettante answer given above is the best PCT
can do, PCT doesn't have anything very interesting to say about Red
Socks Fans. The persistence of masochism may be perfectly
consistent with PCT, but then so is Copernican model of the solar
system.
That's the point. PCT by itself is just a tool, like algebra. What does
algebra have to say about the problem of conserving fossil fuels? To
answer "Nothing" would be quite incorrect, but it would also be foolish
to expect to find the answer by looking in an algebra textbook. Algebra
is not about fossil fuels, but about relationships among variable
numerical quantities. Somebody has to formulate an analysis and get some
data before algebra can help with this problem. Same with PCT and the
Red Sox: somebody has to propose some controlled variables, interview
fans, manipulate what is manipulable, and so forth -- and THEN apply the
principles of PCT. PCT is about relationships among variables in a
system with strong stable negative feedback. Those relationships say
nothing about the Red Sox or their fans -- until someone does the work.
Applying PCT to interpersonal conflicts can be illuminating and can
suggest solutions of the type Ed Ford has developed. Apparently
applying PCT to understanding the appeal of spectator sports is not
nearly so fruitful. This confirms my initial reaction, but is
disappointing never the less.
Ed started with a considerable data base from his practice with
individuals and youthful offenders. He applied the principles of PCT to
his experiences to help him understand what was going on. Studying the
appeal of spectator sports would require an equal amount of study if PCT
were to be applied profitably. This surely could be done. But it
probably wouldn't help the Red Sox much.
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Martin Taylor 960606 14:30 --
Remember the motto of the National Reorganization Association (NRA):
Theories don't explain phenomena; People explain phenomena.
Very wise. But like the motto of the other NRA, a half-truth.
People without theories don't explain phenomena nearly as easily as
do people with theories, and some theories explain more readily
than others. People with some theories can divine implications that
people with other theories cannot, just as some of the weapons
favoured by that other NRA can do their work much more easily than
can others.
My point, which I didn't get around to making, is that while any theory
can provide a plausible-sounding explanation of any phenomenon (in the
hands of the verbally adept), there are ways of testing theories that
can show that some theories are a lot better explanatory tools than
others. The beauty and persuasivess of a theory are seldom an adequate
test of its usefulness.
"What stories we tell ourselves, of origins and endings, of form
and transformation, of gods, the word, and law."
Indeed.
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Martin Taylor 960606 16:00 --
If PCT is correct, all purposive action is to control some
perception(s).
This is a good way to put it, although as Rick explained "purposive
action" and "control" (or at least "attempted control") are pretty much
synonymous in PCT. A commonly misunderstanding of "all behavior is aimed
at controlling perceptions" is "all perceptions are controlled by
behavior." Your way of saying it puts the emphasis on accounting for
actions in terms of the perceptions they are produced to control, which
is better.
The application to Red Sox fans is obvious. What isn't clear is what
perceptions are under control (or are at least intended to be
controlled, if not controlled very well). As you say, some experiments
would be in order.
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P.S. Very sorry you won't be at the meeting, but thanks from all of us
to you for your most generous contribution to the CSG!
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Ken Hacker (960607) --
Would it be possible for Bill to help someone study why a voter
selects on presidential candidate over another? If yes, I would
love to get involved with that kind of PCT application into another
field of inquiry.
An ambitious and worthy undertaking. Yes, I would be glad to help. Maybe
you'd like to come up to my place (a day's drive) for a few days to talk
it over.
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Best to all,
Bill P.