Schedules of Reinforcement

(a) Four types of reinforcement schedule are shown here: fixed ratio, fixed interval, variable ratio, and variable interval. Notice how each schedule differs based on when reinforcement is available (interval schedules) and on how many responses are required for reinforcement (ratio schedules). (b) These schedules of reinforcement affect responding in different ways. For example, notice the vigorous responding that is characteristic of the variable ratio schedule, as indicated by the steep upward trajectory of responding.