[From Fred Nickols (971227.1420 EST)]
Bill Powers (971227.0520 MST)--
Control is a phenomenon, not a theory. An adequate model of control can be
constructed to explain the phenomenon without bringing in all the possible
organizations that are NOT control systems. If we observe that human
behavior demonstrates the properties of control systems, then to explain
what we observe requires only that we explain control. All the other
possibilities become irrelevant until such time as we find some other
identifiable mode of operation.
I pulled the snippet above from your "butting in" post to Martin Taylor
about his interactions with Tim Carey. I did so because I was leafing
through the late Allen Newell's book, "Unified Theories of Cognition,"
earlier today and came across the following remarks (pp.44-45) which I
presume you and/or Rick Marken might care to critique.
"2.2 Knowledge Systems
How then should we describe systems? How should we describe their response
functions? To speak of mind as a controller suggests immediately the
language of control sytems--of feedback, gain, oscillation, damping, and so
on. It is a language that allows us to describe systems as purposive
(Rosenbluth, Weiner, & Bigelow, 1943). But we are interested in the full
range of human behavior and response--not only walking down a road or
tracking a flying bird, but reading bird books, planning the walk, taking
instructions to get to the place, identifying distinct species, counting the
new additions to the life list of birds seen, and holding conversations
about it all afterward. When the scope of behavior extends this broadly, it
becomes evident that the language of control systems is really locked to a
specific environment and class of tasks--to continuous motor movement with
the aim of pointing or following. For the rest it becomes metaphorical.
A way to describe the behavior of systems with wide-ranging capability is in
terms of their having knowledge and behaving in light of it."
Newell continues down the path he, J.C. Shaw and Herbert Simon followed for
years, namely, behavior as produced response functions.
My specific question is this: How would you (or Rick) respond to Newell's
assertion that the language of control systems is metaphorical for all
behavior but that of pointing or following?
Come to think of it, I have a second question. Are there PCT demos that
don't hinge on tracking behavior?
P.S. Your remarks to Martin reminded me of Jay Forrester's chiding of the
current crop of system dynamics gurus for insisting that only those who are
well grounded in advanced mathematics can truly understand, appreciate, or
do really good system dynamics modeling. In full forum at an MIT gathering,
Jay said, "That's simply not true. All you need is some basic math and a
P.P.S. I recall still from my fire control radar days of long ago the
infamous "flip-flop multivibrator" circuit (including the electronic kick in
the pants that was necessary to get it started) and I'm darned if I can see
how knowing about that kind of circuitry is essential to grasping control