1. Schedules of Reinforcement
AP Psychology
Mr. Boyd

2. Reinforcement Schedules
Continuous Reinforcement: Reinforces the desired response each time it occurs.
Partial Reinforcement: Reinforces a response only part of the time. Though this results in slower acquisition in the beginning, it shows greater resistance to extinction later on.
OBJECTIVE 14| Discuss the strengths and weaknesses of continuous and partial reinforcement schedules, and identify four schedules of partial reinforcements.

3. Schedules of Reinforcement
Continuous reinforcement refers to reinforcement being administered to each instance of a response
Partial reinforcement
(intermittent) lies between continuous reinforcement and extinction

4. An Example of Continuous Reinforcement
Each instance of a smile is reinforced

5. Schedules of Reinforcement
Continuous Reinforcement – A schedule of reinforcement in which every correct response is reinforced.
Partial Reinforcement – One of several reinforcement schedules in which not every correct response is reinforced.
Which method do you think is used more in real life?

6. Schedules of Reinforcement
Ratio Version – having to do with instances of the behavior.
Ex. – Reinforce or reward the behavior after a set number or X many times that an action or behavior is demonstrated.
Interval Version – having to do with the passage of time.
Ex. – Reinforce the participant after a set number or X period of time that the behavior is displayed.

7. 4 Basic Schedules of Reinforcement
Fixed-interval schedule
Variable-interval schedule
Fixed-ratio schedule
Variable-ratio schedule

8. Fixed-Interval Schedule
Fixed-interval schedule – A schedule in which a fixed amount of time must elapse between the previous and subsequent times that reinforcement will occur.
No response during the interval is reinforced.
The first response following the interval is reinforced.
Produces an overall low rate of responding
Ex. I get one pellet of food every 5 minutes when I press the lever

9. Fixed Interval Reinforcement

10. Variable-Interval Schedule
Variable-interval Schedule – A schedule in which a variable amount of time must elapse between the previous and subsequent times that reinforcement is available.
Produces an overall low consistent rate of responding.
Ex. – I get a pellet of food on average every 5 minutes when I press the bar.

11. Variable Interval Reinforcement

12. Fixed-Ratio Schedule
Fixed-ratio Schedule – A schedule in which reinforcement is provided after a fixed number of correct responses.
These schedules usually produce rapid rates of responding with short post-reinforcement pauses
The length of the pause is directly proportional to the number of responses required
Ex. – For every 5 bar presses, I get one pellet of food

13. An Example of Fixed Ratio Reinforcement
Every fourth instance of a smile is reinforced

14. Fixed Ratio Reinforcement

15. Variable-Ratio Schedule
Variable-ratio Schedule – A schedule in which reinforcement is provided after a variable number of correct responses.
Produce an overall high consistent rate of responding.
Ex. – On average, I press the bar 5 times for one pellet of food.

16. An Example of Variable Ratio Reinforcement
Random instances of the behavior are reinforced

17. Variable Ratio Reinforcement

19. TYPE MEANING OUTCOME Fixed Ratio Variable Ratio Fixed Interval
Reinforcement depends on a definite number of responses
Activity slows after reinforcement and then picks up
Variable Ratio
Number of responses needed for reinforcement varies
Greatest activity of all schedules
Fixed Interval
Reinforcement depends on a fixed time
Activity increases as deadline nears
Variable Interval
Time between reinforcement varies
Steady activity results

20. Comparisons of Schedules of Reinforcement
FORM OF REWARD
INFLUENCE ON PERFORMANCE
EFFECTS ON BEHAVIOR
SCHEDULE
Fixed interval
Reward on fixed time basis
Leads to average and irregular performance
Fast extinction of behavior
Fixed ratio
Reward tied to specific number of responses
Leads quickly to very high and stable performance
Moderately fast extinction of behavior
Variable interval
Reward given after varying periods of time
Leads to moderately high and stable performance
Slow extinction of behavior
Variable ratio
Reward given for some behaviors
Leads to very high performance
Very slow extinction of behavior