Schedules of Partial Reinforcement

Reinforcement schedule

Rules about the timing and frequency of reinforcing a particular response that determines the speed and strength of operant learning (training)

Continuous reinforcement

Response is reinforced every time (coke machine)

∙Rapid acquisition

∙Rapid extinction

Partial reinforcement

Response is reinforced only part of the time (slot machine)

∙slower acquisition (learning)

∙slower extinction

Fixed-Ratio Schedule

Reinforcement is given only after an exact number of responses are made.

Typical outcome of Fixed-Ratio Schedule and rate of responding.

Only short pauses occur after each response, because more responses yield more reinforcement. So, FR schedules produce the highest rate of responding.

Example: get paid for number of yards you mow.

Result: You mow (response) more yards so you can get more pay (reward

Fixed-Interval Schedule

Reinforcement of a response occurs only after a fixed period of time (NOT response based).

Typical outcome of Fixed-Interval Schedule and rate of responding.

Slow, steady responses; second slowest rate of responding.

Example: you get paid once a month (reward) no matter how many hours you work (response).

Result: tend to work slow and steady, only as much as you have to do.

Variable-Ratio Schedule

Reinforcement occurs after a varying (unpredictable) number of responses are made.

Typical outcome of Variable-Ratio Schedule

Responding occurs at a high, steady rate, and is the hardest to extinguish. Example: your chances for jackpot (reinforcement) increase with more scratchoff purchases (response) Result: you buy a scratchoff every time you go to the gas station.

Variable-Interval Schedule

Reinforces a response at unpredictable time intervals

Typical outcome of Variable-Interval Schedule and response

Produces a steady stream of slow responses; slowest but most steady rate of responding

Example: checking facebook (response) to see if anyone tagged you (reinforcement)

Result: tend to check your FB at regular times (once a day, every morning and every evening, etc.)

How to determine the schedule of reinforcement

1. Does the reward come after some amount of time (interval) or after I make some number of responses (ratio)?

2. Do I know exactly how much time or exactly how many responses (fixed) or is it unpredictable (variable)?

Remember that schedules of reinforcement ALWAYS involve a reward because the whole point is to reinforce (increase) a desired behavior!