Cumulative Record. Chapter 17: Contingency Management in the Classroom. Quote 20

No matter how bad a teacher may be, he has at least one available reinforcer—dismissing his class . . . He should wait until the behavior of the class is as acceptable as it is likely to be and then dismiss. But almost inevitably he will do the wrong thing: he will tend to dismiss the class when trouble is brewing . . . In doing so he gets out of today’s trouble, but a fight will be more likely to start tomorrow. (p. 280)