In the relationships involving formal control, such as the ones we’ve examined thus far, each controlling variable strengthens only a single response form. This is not true for the relationships to be presented next.
When a controlling variable evokes a response and has the following features:
There is point-to-point correspondence between the controlling variable and the response
Whether or not there is formal similarity between the controlling variable and the response
Formal characteristics of either the controlling variable or the response
Dynamic characteristics of either the controlling variable or the response