[From Rick Marken (950908.1000)]
Bill Powers (950907.1044 MDT) to Hans Blom (950907) --
If the world-model-based control system is to be considered the general
case as you prefer to do, and the simple negative feedback control
system only a special case, then it would be necessary to demonstrate
that the world-model-based system could in fact handle the situation in
the diagram
Demonstrating that would in turn require showing that either a design
engineer or an adaptive control scheme (I don't care which you use)
could in fact design a system that could compensate for any possible
waveform of the additive disturbance, AND DO SO AT LEAST AS WELL AS THE
SIMPLE NEGATIVE FEEDBACK CONTROL SYSTEM COULD DO IT. That is the essence
of my challenge
So, Hans, do you accept the challenge? I think it would be a real eye-opener
for you (and us).
Marc Abrams (950906.1600) --
It is _not_ easy having a "conversation" on the net. All the more reason to
test our assumptions. Unfortunately that might make for super long and boring
threads. Anyone have a suggestion?
I think it is a great idea to use net discussions themselves as a basis for
testing assumptions about what people are controlling for. This may, indeed,
lead to super-long threads but I'm quite sure these threads would not be
boring. When you test assumptions about what people are controlling for, you
intentionally try to "push" on what you suspect is a controlled variable. The
reaction you get, when you guess right, can be quite intense -- and, for
voyeurs on the net, possibly quite interesting.
One problem with using the net for testing for controlled variables is that
we are limited in the kind of (potential) disturbances we can apply --
basically just written sentences. The effectiveness of these disturbances
depends on the verbal skills of tester and testee; of course, the effect of
these disturbances sldo depends on how they are understood by tester and
testee.
Another problem is that verbal disturbances are a very "blunt" instrument;
any statement is likely to be a disturbance to many different controlled
variables so it will be difficult (impossible?) for a tester to say something
that gets no reaction. Note that, in the "coin game" described in B:CP, the
way the tester proves that he has identified a controlled variable is by
making 3 moves (disturbances) that require correction and 3 that DON'T. I
think it would be difficult to find three verbal statements that were not a
disturbance to something an individual was controlling. But I think it should
be possible to vary one's verbal expressions in such a way that it becomes
relatively clear that some statements result in far greater correction than
others.
One last point: it can be extremely disturbing (in the PCT sense) to have
someone guessing at what we are controlling for. One reason for the
disturbance is that their guess is likely to disturb other variables we are
controlling for (if someone guesses that I am controlling for marrying my
mother and killing my father, I would get a bit pissed since, at least
consciously, I don't want to marry my mother or kill my father (quite
the opposite;-)). Another reason for the disturbance is that many people seem
to control for not having their intentions known; even if I really do want to
marry my mother, for example, I might find your discovery of this intention
disturbing because I intend to keep my intentions to myself.
So the use of the use of verbal statements to test for controlled variables
on the net is fraught with potential difficuties; it can lead to angry
exchanges (disturbance resistance) and fierce disagreements ("I am not
controlling for blah blah"). But I think it can also be illuminating -- VERY
illuminating. After all, many of our most important interactions -- including
clinical, management and teaching interactions-- are highly verbal. We have a
laboratory for exploring control right here in front of our finger tips. I
say we use it -- and TRY to keep in mind (when conflicts become intense) that
we are all human beings who love our kids and feed our pets.
Let the testing begin.
Best
Rick