[From Rick Marken (930823.0900)]
Michael Fehling (930823a)--
agents as engaged in on-going (i.e., continuous and real-time), closed-loop
interaction with its physical and social environment.
We do too. But we also note that this closed loop interaction results in a
phenomenon called "control". Control is the process of keeping a perceptual
variable, p, matching a constant or varying reference specification, r.
maintain control (keep p = r) by varying their actions (o) as necessary
to counteract environmental disturbances (d), keeping the environmental
correlate (i) of the controlled perceptual variable at the value that produces
the appropriate value of p. The process of keeping p = r is also called
purposeful behavior. So the phenomenon of control is equivalent to what
has always been described as "purpose".
However, in any general model of control of action, including PCT, some
reference standard must be posited.
We've got some verbal problems here. PCT is not a model of control of
"action". We use the word action to refer to organism-produced
influences on the environmental correlates of controlled perceptual
variables. These actions are not controlled; they are caused -- ultimately,
by efferent neural signals. It is the perceived consequences of these
actions that are controlled -- ie. maintained at a constant or varying
reference level (specified inside the agent) against environmental
disturbance. The reference "standard" is not only positied by PCT --
it is one of the most important concepts in the model. The reference
standard, r, is an agent-specified neural signal -- the same KIND of
signal as the perceptual signal, p -- that "commands" the intended
value of p. The negative feedback closed loop that runs through the
environment is responsible for the fact that p TRACKS r -- p is
controlled relative to r.
A task, goal, or any
other representation of an objective is just a reference standard at a
relatively high level of abstraction. So, when an onlooker attributes task
objectives to an agent, s/he seems not to be violating the spirit of control
theory such as PCT.
This is true -- r could specify a p that represents a task like
"hammering a nail". Bill's point (I think) is that the "task" that the
observer sees may not correspond to the perception(s) that the
agent is controlling. There is a formal procedure, called "the test
for the controlled variable", that must be used by observers to test
hypotheses about the extent to which aspects of their own perceptual
experience (what most of us succumb to calling the "actual state of
affairs") corresponds to perceptual variables that the agent is
controlling. For example, it may look, to an observer, like an agent
is hammering a nail when, in fact, the agent is controlling a rhythmic
pattern that s/he wants to try at the club latter that night.
The validity of these ascriptions is, however, an empirical matter.
Yes, indeed. And "the test for controlled variables" is an empirical
approach to testing the validity of these "ascriptions" (hypotheses
about controlled perceptual variables). I have never seen any
formal or informal use of "the test for controlled variables" in any
of the literature on "task analysis" or cognitive modelling. I would
be very interested to know if the "validity of these ascriptions"
has ever been tested empirically in cognitive psychology.
So, Albus' model is not flawed just because it "speaks of
'tasks' that an organism carries out.
It is flawed because he never "tested the validity of his ascriptions".
Like most behavior modellers, he was "flying by the seat of his
pants", taking appearances (his own perceptions of behavior) com-
pletely for granted.
Instead [of "behaior"], I prefer the term "action" (as a
capability subjectively defened by, perceived by, and under the control of,
the agents being described).
Sounds like your "action" is what we call a "controlled perception", p.
as I said, we use the term "action" to refer to uncontrolled outputs (o).
I try to reserve the term "behavior" for
reference to observable properties of actions.
We usually use the term "behavior" to reer to the controlled consequences
of actions (as perceived by a observer). The problem is that "action"
and "behavior" are relative terms; a behavior in one context may be
an action in another. The movement of a hammer is a controlled result
of muscle forces; so hammer movement is a behavior -- a result of
the actions of the muscles. But movements of the hammer are used
to drive nails into wood. So now hammer movements are the actions
that produce another controlled result -- "nail into wood" behavior.
In PCT, "action" is synonymous with "means" and "behavior" is synonymous
with "ends". The relativity of action and behavior is captured by the
hierarchical structure of the PCT model.
Of course, the problem is that no descriptive theory can avoid commiting to
some things that in another theory are "mere appearances."
True. And it's one reason PCT is a GENERATIVE theory (it actually behaves
and is tested by the degree to which it mimics the behavior of living
systems) NOT a descriptive theory.
1. Many of the perceptions that agents control are just the kinds of
appearances of which you warn. I.e., they are attributions that the agent
uses to structure its self-perceptions and then use these attributions for
Have you tested to determine that this is, indeed, what these agents are
controlling? Even if you have not, I agree that aspects of what people
control are based on "imagination" (self-generated perceptions that
are not based on external reality) -- so, in general, p =f(i,im); perceptual
variables are a function of both the sensory consequences of environmental
variables (i) and self-generated perceptual inputs (im). I think this is what
you mean in your "i.e.".
Do you know of any work in PCT that would be relevant?
I have a working hierarchical control model (3 levels, 6 systems at
each level) that is implemented in Lotus and Excel spreadsheets.
A different "type" of perecption is controlled by the systems at
each level of the hierarchy. It is possible to put some of the
systems into "imagination mode" so that the perceptual signals
in higher level systems are based, in part (or in full) on imagined
perceptions. It is possible to see the consequences of this kind
of imagination on the operations of the control hierarchy (these
consequences are surprisingly small).
Social psychologists and others have proposed another important type of
"appearance"--a concept or attribution that plays a role in the social
construcion of the self. Here, too, I am approaching this topic from a
systems perspective. Is there PCT-related work that tries to shed light on
PCTers have done very little work on the control of high-level perceptual
variables (like "self") or on the workings of imagination (attribution).
Michael Fehling (930823b) to Tom Bourbon 930823.1230 --
We are studying how the organzation controls its own operations in order to
achieve its objectives.
An organization is a collection of agents (human control systems) is it not?
I don't see how this collection of agents can have objectives. The agents
can have objectives becuase they have nervous systems that can function
as control systems. Organizations can "appear" to have and achieve
objectives -- but this is truly an appearance. It is not what is going on.
I think you should take a look at Bill Powers' "Gatherings" program to
see how the appearance of organizational "control" (achievement of or-
ganizational objectives) "emerges" out of the operation of many independent
control system controlling variables that sometimes involve one another.
Similarly to PCT (I think), our model requires that
the organization and its decision making units accomplishes this control in
terms of its interpretations of environmental conditions.
In PCT, the "interpretation" of environmental conditions determines
WHAT is controlled. The controlled variable, p, is a function of environ-
mental conditions, i; p = f(i). f() is the "interpretation" of the
conditions. The nature of f() determines WHAT aspect of the environment
is controlled. If this is what you mean by "accomplishes control in terms
of its interpretations of environmental conditions" then your model is like
PCT in this sense.
In sum, this model approaches organiational performance as a process of
adaptive control. Since we emphasize the way in which the organzation's
perceptions do or do not correspond to actual external conditions, our model
seems compatible with the tenets of PCT.
PCT does not make a big thing out of correspondance; you control what you
perceive: that's it. I don't see how organizations can have perceptions --
agents in the organization can have them, organizations can't (as far as
I know). PCT certainly is relevant to the behavior of organizations -- but
it would model this behavior in terms of agents, not fictional entities
(like organizational perceptions and objectives).