No, it wasn’t the post about the TV ad. Might have been something Bill said in person at a conference, or it might be that I couldn’t find it hidden under the … expansion widget at the bottom of a post in the search results.
Ah, I assumed you would get the reference.
Absence of observable output is not evidence of absence of control. Inadequacy of output (e.g. in a tug of war) is not evidence of absence of control. If your daughter’s distress was evidence for a reference for agreement between visual vertical and inertial vertical it was also her means of control ("Daddy, fix it!). I bet it worked.
There’s a value for “V as influenced by d” if V is not controlled. This value is provided by controlling principles of physics (or whatever) and operations of mathematics in combination with observed values of V and d, and by these means controlling a perception of the expected value. The means of controlling this perception of the expected value of V are not of the same kind as the subject’s means for controlling her perception of V. The controlled perception “expected state of V as influenced by d” is one input to a higher-level system which compares it with its other perceptual input, the “observed state V as influenced by d”.
Concurrently, the investigator is controlling a perception of d. This control of d does indeed conflict with the subject’s control of V. However, the investigator purposely constrains the magnitude and duration of d so that the subject easily overcomes the disturbance and thereby demonstrates the fact of control and its reference value. This constraint is presumably imposed by higher levels of control, perhaps at the same level as the system that is comparing expected and actual values of V. So far as I know, no one has modeled this purposeful limitation of a deliberately introduced conflict, though I have sketched a diagram:
The little green rectangle in the environment is V as hallucinated by both parties, that is, they experience their respective perceptions as realities in the environment. The perceptual input for the experimenter is not labeled p, it is labeled q.i because that is our name for the particular perception that the experimenter is controlling: a value which by inference corresponds to the value of the perceptual signal p inside the subject. That inference is supported (or not) by the experiment, the Test. The disturbance values shown in the environment are also perceptions in side the experimenter, but they are shown as the experimenter projects them to be in the environment. They are perceptions in control loops which are not shown: controlling a bit of conflict with the subject, experimentally, and managing extraneous variables in the experimental setup. Also not shown are a loop controlling the value predicted by physical sciences sans control, and a loop comparing the expected vs. actual value of V, as discussed above.
And thus, the experimenter is controlling a perceptual signal q.i, a perceptual analog in her head of a variable aspect of the world located inside the subject’s head, a perceptual signal p. The signal q.i is controlled by means of devices and procedures for measuring and recording influences on the subject’s sensory organs. Concurrently, in the other “real” world, the experimenter experiences a perception V as existing in the environment, and with it the perception that she has confirmed that it is the same as a perception V that the subject is experiencing as existing in the environment.
As good William Shakespeare put it, all of this, and we as well,
… are such stuff
As dreams are made on, and our little life
Is rounded with a sleep.