Rick,
Yes, I tried to show in text that the quotation was from Powers. (I wrote the message in Discourse interface and used its quote tool and it made it seem like it was yours.)
Yes, I think he (Powers) really made an error by identifying the perception and the object of that perception.
But then later in my message I stated just like you that the “Controlled Variable” is a perception of the observer / experimenter in the TCV – or at least that the experimenter’s decision what is the Controlled Variable is based on his/her own perceptions about the same physical variables which the controller is perceiving.
That decision (of what is the Controlled Variable) can be reliable and reasonable only if the input functions of the controller and the observer are either originally similar enough or if the observer’s input functions are extended with an aid of some technical advices (and/or some special training) so that after that it is similar enough with that of the controller. The study of bat’s controlling requires that latter case.
Best
Eetu