[From Rick Marken (960226.1300)]
I said:
There is always direct, visible feedback about the state of a controlled
perceptual variable.
This, of course, is not true. There are times when we are unable to perceive
a variable that we are controlling (or trying to control). I should have said
that _most of the time_ we are able to percieve the variable we are
controlling. During the occasional times when we cannot perceive a variable
that we are controlling (as when reach for our shoes in a suddenly darkened
room), we are _not_ controlling that variable. If we are lucky and no
significant disturbances occur during the period that we are unable to
perceive the controlled variable, we can generate responses "open loop" that
keep the controlled variable in the state we would have wanted to perceive it
in if we could perceive it (we get the shoes). It will appear to a naive
outside observer (like Hans Blom) that there is control during the period
when there is no perception; but there really is not control; just luck. If
someone had moved the shoes during the period of darkness there would have
been no control (we would not get the shoes--until the lights came on).
Best
Rick