Final answer:
Shaping is a differential reinforcement procedure that helps increase behaviors displayed too infrequently by reinforcing successive approximations of the desired behavior.
Step-by-step explanation:
In the context of behavior that is displayed too infrequently, the differential reinforcement procedure that helps increase the behavior is called shaping.
In shaping, instead of only reinforcing the target behavior, we reinforce successive approximations of the behavior. This means that we initially reinforce any response that resembles the desired behavior, and then progressively reinforce responses that more closely resemble the desired behavior until only the desired behavior is reinforced.
For example, if the desired behavior is for a student to study for longer periods of time, we can start by reinforcing the student for studying for even a few minutes, then gradually increase the required study time for reinforcement.