Explain the various types of intermittent schedules of reinforcement and how rates of responding ...

ANSWER:
There are essentially four basic types of intermittent reinforcement schedules that represent combinations of four factors. Those four factors are (1) the number of responses that occur between reinforcements, or (2) the elapsed time that occurs between reinforcements, and whether the schedule of delivery of the reinforcers is (3) fixed throughout the period of reinforcement, or (4) varies during the period of reinforcement. Thus one can use (1) fixed-interval, (2) fixed-ratio, (3) variable-interval, or (4) variable-ratio reinforcement schedules. Fixed-interval schedules deliver the reinforcers with uniform time periods between reinforcers. Fixed-ratio schedules deliver the reinforcers after the organism has responded a set number of times. Variable-interval reinforcement schedules deliver the reinforcers after some period of time has elapsed since the first response, but the elapsed time period varies between reinforcements. Variable-ratio schedules deliver the reinforcers after a given number of responses, but that number varies between reinforcements. Research has shown that both of the ratio schedules produce very high rates of responding (typically higher than interval schedules). Fixed-interval schedules have a characteristic scallop shape that results from a drop in the rate of responding immediately after each reinforcement.