# The Test for the Controlled Variable

**URL:** <http://discourse.iapct.org/t/the-test-for-the-controlled-variable/134>\
**Category:** Methodology\
**Created:** [November 1, 2019, 7:53pm UTC](http://discourse.iapct.org/t/the-test-for-the-controlled-variable/134 "2019-11-01T19:53:06Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![bnhpct](http://discourse.iapct.org/user_avatar/discourse.iapct.org/bnhpct/32/34_2.png) [@bnhpct](http://discourse.iapct.org/u/bnhpct)\
**Post date:** [November 18, 2020, 11:15pm UTC](http://discourse.iapct.org/t/the-test-for-the-controlled-variable/134/3 "2020-11-18T23:15:55Z")

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In the topic [Controlled variables are perceptual variables](http://discourse.iapct.org/t/controlled-variables-are-perceptual-variables/15681/28), 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.

> [@Controlled Variables are Perceptual Variables](http://discourse.iapct.org/t/controlled-variables-are-perceptual-variables/15681/28):
>
> [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.

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