[From Rick Marken (930923.1430)]
In re-reading Chris Wickens' post I found something that could
make Greg Williams' day (ie. I would have to admit that the
manual control work WAS a parallel development to PCT).
Chris Wickens says:
Finally, an issue was made of measurement. How can we measure what is
the basis (the intentions) of control behavior. Jex Jewell and Allen
have looked at this in terms of trying to characterize the shared
covariannce of output with different aspects of input, in order to
ascertain the extent to whcih subjects WERE responding to error
(compensatory behavior) or other aspects of the environment (pursuit
behavior)....Sorry. Make that Allen and Jex. I have often found
theirs to be a particularly elegant approach, of using control theory
to diagnose intentions.
Actually, this sounds a LOT like it might be a test for the
controlled variable. Could you give a more detailed description
of their method; if they knowingly did "the test" then I'll really
have to eat crow.
Of course, you don't really mean that Allen and Jex were trying
to "ascertain the extent to which subjects were RESPONDING to
error or other aspects of the environment", right? We all know
that control systems control perceptual aspects of the environment;
they don't _respond_ to them. So Allen and Jex must really have been
trying to ascertain whether subjects were controlling perceived
"error" or other perceived aspects of the environment, right?
Sounds like "the test for the controlled variable" to me. Could you
please describe the study in some detail -- it's apparently in a
technical report and not readily accessible to me. I'm prepared to
recant.
Best
Rick