The Test for the Controlled Variable

[bnhpct]

In the topic Controlled variables are perceptual variables, Adam included Bill’s brief definition of the Test in a 1996 email exchange. It’s worth associating with this topic for the record. In the larger context, Bill affirms that the CV is a perception controlled by the observer.

@amatic

[From Bill Powers (961224.1145 MST)]
[…]
The CV is defined by the Test, and is basically a perception in the
observer, reified as part of “the environment.” We apply disturbances to
something in the environment, with an expectation of how the disturbance
would change it if there were no control. We strongly suspect the existence
of control if the variable to which the disturbance is applied changes much
less than we expected. The test is completed by showing that preventing the
other system from perceiving the variable destroys control, and that the
reason for the small effect of the disturbance is opposition by an action
of the controlling system. So the CV that we discover exists in “the
environment” and is as objective as any other measure of the environment.
We can be mistaken about the CV, in that the other person might be
controlling a perception derived from the environment in ways different
from our way of perceiving the CV, or might be controlling something
closely related to our concept of the CV but not identical to it, and so
on. We must, of course, be aware of this and not settle for the first
definition that we stumble across.