[from Mary Powers 940223]
Gary Cziko (940215)
After a long discussion with Bill about closing the
enviironmental part of the loop through another person, I think I
agree with you. It is possible to use other people to amplify our
outputs and alter the environment into the state we desire (tidy
room, no pizza crusts), and therefore what they do for us is
feedback.
The only problem with this concept is that it is easily confused
with the same externally similar process in machines which are
not control systems - you push a button or step on the gas and
the machine obeys your command. This quickly leads to the kind of
confusion that was evident in Ozmo's belief that he was affecting
the reference signals directly in his platoon.
I got carried away by a dislike of the idea that other people
give or withhold feedback. If someone gives or withholds
information, does what you want or doesn't, you are getting
feedback either way - either the environment is cooperating with
you or it is creating a disturbance. It is not in the power of
another to turn feedback off or on - the loop is always closed
(unless perceptions are blocked).
Also, in my experience, people who blather about giving and
getting feedback tend to be the same ones who think positive
feedback is good and negative feedback is bad.
Bill Leach (940215)
I think you misread Gary. Nothing wrong with how he used the
terms positive and negative feedback. If his daughter refuses to
clean her room when he asks, and in fact makes it messier, it
increases his error - positive feedback - and, being a negative
feedback system, he counters the greater error with more effort.
What's going on here is not the popular notion that positive
feedback is good and negative feedback is bad. It's the positive
feedback that occurs when two different control systems are
trying to control the same variable (the messiness of a room) at
two different values.
Cliff Josslyn (940220)
I really liked your post of 2/22 in so far as it expresses your
thinking on ST, CT, and cybernetics (and your high opinion of
Bill!).
But in your 2/20 post you asked Rick for specific criticisms of a
number of systems theorists, and I'm rising to that bait.
In Robots, Men and Minds, von Bertalanffy describes a cybernetic,
or control system, this way:
The minimum elements of a cybernetic system are a "receptor"
accepting "stimuli" from outside as input; from this a
message is led to a "center", which in some way reacts to
the message, and, as a rule, amplifies the signals received;
the center, in its turn, transmits the message to an
"effector", which eventually reacts to the stimulus with a
"response" as output. The output, however, is monitored
back, by a "feedback" loop, to the receptor, which senses
the preliminary response and steers the subsequent action of
the system so that eventually the desired result, a "target
value" (Sollwert), is obtained. In this way, the system is
self-regulating.
This is pretty confused. Is the "center" the comparator? If so,
where is the reference signal? Apparently in the receptor, doing
the steering. Where is the result desired? And so on. Von B goes
on to say
...the cybernetic model is the familiar S-R (or S-O-R)
scheme, with the feedback loop added to make the system
self-regulating.
And he makes that statement, not just in this popularization, but
in a number of more scholarly places, quite dismissively. He then
goes on to say that cybernetics systems are "closed" and
therefore the cybernetic model fails to provide for an essential
characteristic of living sustems - growth, development, and
differentiation. And following that, are not self-organizing,
i.e. cannot evolve from a less to a more differentiated state,
"can only increase in their entropy content and decrease in
information content" and so on and so forth, winding up by saying
that while it provides insight into regulatory, goal-seeking and
teleological behavior (it's hard to see how), it falls short of
"providing a new 'natural philosophy'". He then quotes Bronowski,
who said
Cybernetics remains in the best sense a fundamental idea as
well as a popular one, but it has turned out to be less
embracing, and, in an odd way, less interesting than we had
hoped 20 years ago when it was first conceived.
This of course was the end of cybernetics' - or control theory's
- brief run as "trendy", and why PCTers are considered by some to
be rather quaintly old hat. I think von B. was essentially
clueless about control theory and extremely influential in
promoting his view of its unimportance. And that this is why even
cybernetics has resisted the idea that it is about control
theory.
Bob Clark (940218)
If you believe that all levels of the hierarchy are engaged in
making decisions, then I guess it follows that you have to have a
DME to do it. But are you so certain that "examining, comparing
and selecting among the available (remembered) principles" is
really taking place, what is really going on, at the principle
level - or at any level other than the program level?
In my going to town strategy, various principles are in play, and
one or another course of action results in increasing error in
some and reducing error in others. But I don't think that what I
am doing is deciding among them. I think that what is happening
is that I am minimizing error in general, without regard to which
specific principles are involved. The biggest error will get the
most action to reduce the error, and consciousness - or decision-
making - is not required. Minimal errror is simply the
configuration a control system naturally falls into, the
consequence of its design.
If consciousness enters into it at all, it is only when one or
more principles are in severe or chronic conflict with others (I
think we tolerate small errors if the overall system is fairly
comfortable). But conflict among principles is not to be resolved
by deciding to favor one over another. This does not make the
error in the conflicting principle, or the principle itself, go
away, though it may make it go underground, inaccessible to
consciousness. Our hints from psychotherapy are that such
conflict can only be resolved by allowing the hidden principle
back into consciousness, and then by going up a level, to where
incompatible principles come from, and resolving them there, not
by deciding on the one we want, but by reorganizing.( My personal
experience has been that this rather mysterious process - insight
into conflict - involved reorganizing my self concept in such a
way that one side of the conflict simply disappeared - it became
irrelevant - not-me).
What you are talking about, however (in my view), is a process of
symbolizing principles, expressing them in words, at a level
below the program level, and then operating on the symbols from
the program level, where logic and decision-making are. The idea
of taking higher-level concepts and manipulating them in
imagination as though they were objects, or sequences, or
relationships, or whatever, is not new, and I think it very
nicely fits this situation. I said before that it seems to me
that most people operate at the program level most of the time,
and I will expand that here to say that I think this applies very
particularly to you, with the importance you attach to decision-
making and your inflation of it into an Entity.
My decision to mention Lord and Hanges and their decision-making
mechanism lay in the similarity of it to the DME both in name and
in the arbitrary addition of it to PCT (in my words elsewhere, a
"gratuitous embellishment"). I mentioned it primarily to ring a
bell or two in other participants on the net who have read L&H to
show to where I am coming from and what I think of the DME. This
was a strategy designed to say that I think the DME is pretty
stupid without saying so to your face, thereby expressing a) the
principle that dreaming up special Entities to take care of
things that puzzle you about PCT is not a good way to go about
developing the model, and b) the principle that saying directly
that I think the DME is stupid is not very nice.
I think your objection to my juxtaposing statements from
different posts is a quibble. You said it, I quoted it. They
looked inconsistent to me and I need no justification for
pointing that out. Your later corrections and expansions make
your thinking somewhat clearer, which was the point.
Mary P.