Psychology - Mr. Duez -- Unit 3: Learning -- Schedules of Reinforcement --Operant Conditioning
Operant conditioning (instrumental conditioning) involves an organism’s learned response in order to obtain a reward.
The response is an action not typically associated with obtaining a particular reward. B.F. Skinner pioneered the study of
operant conditioning, although the phenomenon first was discovered by Edward L. Thorndike, who proposed the law of
effect, which states that a behavior is more likely to recur if reinforced. Skinner ran many operant-conditioning
experiments. He often used a specially designed testing apparatus known as a Skinner Box.
Behaviorists use various schedules of reinforcement in their experiments. A schedule of reinforcement refers to how
often an organism receives reinforcement for a given type of response. In a continuous reinforcement schedule, every
correct response that is emitted results in a reward. This produces rapid learning, but also results in rapid extinction,
where extinction is a decrease and eventual disappearance of a response once the behavior is no longer reinforced.
Schedules of reinforcement in which not all responses are reinforced are called partial (or intermittent) reinforcement
schedules.
A fixed-ratio schedule is one in which the reward always occurs after a fixed number of responses. Fixed-ratio schedules
produce strong learning, but the learning extinguishes relatively quickly.
A variable-ratio schedule is one in which the ratio of responses to reinforcement is variable and unpredictable.
Reinforcement can come at any time. This type of schedule takes longer to condition a response; however the learning that
occurs is resistant to extinction.
A fixed-interval schedule is one in which reinforcement is presented as a function of fixed periods of time, as long as
there is at least one response.
Finally, in the variable-interval schedule, reinforcement is presented at differing time intervals, as long as there is at least
one response. Variable-interval, like variable-ratio, is more difficult to extinguish than fixed schedules.
Learned helplessness occurs when consistent effort fails to bring rewards. If this situation persists, the subject will stop
trying. Psychologist Martin Seligman sees this condition as possibly precipitating depression in humans. If people try
repeatedly to succeed at work, school, and/or relationships, and find their efforts are in vain no matter how hard they try,
depression may result.
A chart demonstrating the different response rate of the four
simple schedules of reinforcement, each hatch mark
designates a reinforcer being given (Reinforcement, 2005)
In operant conditioning, schedules of reinforcement are an
important component of the learning process. When and how
often we reinforce a behavior can have a dramatic impact on
the strength and rate of the response.
In real-world settings, behaviors are probably not going to be
reinforced each and every time they occur. For situations
where you are purposely trying to train and reinforce an action,
such as in the classroom, in sports or in animal training, you
might opt to follow a specific reinforcement schedule. As you'll
see below, some schedules are best suited to certain types of
training situations. In some cases, training might call for
starting out with one schedule and switching to another once
the desired behavior has been taught.
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EXAMPLES:
F or V R or I
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Getting a paycheck every other week
2
Pop quizzes
3
Slot machines at gambling casinos
4
A factory worker is paid on piece work
5
Fly fishing: casting & reeling back several times before catching
a fish
6
Looking at your watch during a lecture until the end of the 90
minute period.
7
A salesperson who is paid on commission (% of sales)
8
Calling a friend & getting busy signal because he or she is
frequently on the phone
9
Signaling with your thumb while hitchhiking
10 Frequent flyer program: reward after X amount of miles
11 Buying loterry tickets
12 A person refrains from drugs due to random drug testing
13 Checking the refrigerator to see if JELL-O is ready
14 Watching for shooting stars
Hints:
Fixed = specific
Variable = unpredictable
Ratio = number
Interval = time period
Fixed Ratio = specified number of responses
Variable Ratio = unpredictable number of responses
Fixed Interval = specified time period
Variable Interval = unpredictable time period
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