From Tom Bourbon [931116.1053]
Apropos of the continuing saga, "information-now-fluctuations in perception
about the disturbance," fools rush in . . ..
From time to time, an agent (a person or another animal) seeks to determine
the relative degrees to which the state of a controlled variable is affected
(1) by the agent's continuous actions and (2) by a net independent
disturbance that is also continuous. In such instances, the agent is
confronted by an ambiguity well-documented on this net: the state of the
CEV is jointly and continuously determined by the agent's actions and the net
disturbance.
There are at least two ways for an agent (a person or another animal) that is
continuously controlling its perception of a specific CEV to (try to) obtain per
ceptual
information, in the day-to-day meaning of the word, about the relative
contributions to the state of the CEV originating from her, his, or its
own actions, and from the net effect of independent disturbances. Both
strategies are limited to control systems with more than one simple
control loop. Here, I will leave open the question of precisely how much
additional complexity is required.
1. The controller can stop acting on the control manipulandum (which may
be part of its own body). In that case, the state of the now-uncontrolled
"CEV" is determined by the net disturbance, which may be zero.
2. The controller can act to "overwhelm" the net disturbance. In that case,
depending on the relative efficiency of the agent and any net disturbance,
the state of the CEV may be determined primarily by the agent's actions.
For people, examples of these two strategies are common. They often
release their grasp, or other actions, on a control device (stick,
wheel, rope, hand of another person, etc.) and observe what happens to the
controlled variable. Similarly, they often produce exaggerated actions
(pushes, pulls, tugs, tweaks, flips, etc.) on a device and observe
what happens to the controlled variable. Most of us have probably done
similar things to learn if *we* are affecting a variable, or if it is
changing "on its own;" or to determine if we have correctly identified which
of several possible devices should be used, or if a device is "still
working."
Under either strategy, the agent's actions might produce garden variety
(aka plain vanilla) information about the relative degrees to which it and
a net disturbance can affect the CEV. Having attained that new knowledge,
the agent still does not know, moment by moment during continuous control,
the amount by which the present state of the CEV is determined either by its
own actions or by the net disturbance.
Fool exits stage left.
Tom