Cumulative Record. Chapter 20: What Is Psychotic Behavior? Quote 9

A man may walk down the street in precisely the same way upon two occasions, although in one instance he is out for exercise and in another he is going to mail a letter. And so it is thought necessary to consider, not the behavior itself, but “what it means” to the behaving individual. But the additional information we are trying to convey is not a property of behavior but of an independent variable. (p. 313)