Transcript CHAPTER 13

Chapter 13:
Schedules of Reinforcement
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Schedules of Reinforcement
• Continuous Reinforcement (CRF)
– Provides reinforcement for every occurrence
of a behavior.
– Advantageous for skill acquisition
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Schedules of Reinforcement
• Intermittent Schedules of Reinforcement
(INT)
– Used to strengthen established behaviors
– Usually necessary for the progression to
naturally occurring reinforcement.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Schedules of Reinforcement
• Basic Schedules of Reinforcement
– Ratio (instances) and Interval (time)
• Ratio schedules require a number of responses
before one response produces reinforcement
• Interval schedules require and elapse of time
before a response produces reinforcement.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Ratio Schedules
– Require a number of responses before one
response produces reinforcement.
– A fixed number of “instances” or
“occurrences” of the correct target behavior.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Interval Schedules
– With an interval schedule, a specific amount
of time elapses before a single response
produces reinforcement
– Reinforcement is contingent only on the
occurrence of one response after the required
time has elapsed.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Fixed Schedules
– With a fixed schedule, the response ratio or
the time requirement remains constant.
• Fixed Ratio 4 (FR 4) – Reinforcement is delivered
after every 4th correct response.
• Fixed Interval 2 min (FI 2) – Reinforcement is
delivered for the first response after the 2 minutes
have elapsed.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Fixed Ratio and Schedule Effects
– Consistency of Performance
• Produces a typical pattern of responding
– After the first response of the ratio requirement, subject
completes required responses with little hesitation
– Postreinforcement pause follows reinforcement
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Fixed Ratio (FR) and Schedule Effects
– Rate of Response
• Often produce high rates of response
• Larger the ratio requirement, the higher the rate of
response.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Fixed Ratio (FR) Schedule Effects
A = Post reinforcement pause
Responses
B
B = High rate of response “run”
A
C = reinforcer delivered upon
emission of nth response
C
Time
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Variable Schedules
– The response ratio or the time requirement
can change from one reinforced response to
another.
– Variable Ratio – 4 (VR 4). An average of
every 4th correct occurrence
– Variable Interval 2 minute (VI 2). Reinforcing
the first occurrence after an averaged elapsed
time of 2 minutes.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Variable Ratio (VR) and Schedule Effects
– Consistency of Performance
• Produce consistent, steady rates of response
• Do not produce a postreinforcement pause
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Variable Ratio (VR) and Schedule Effects
– Rate of Response
• Tends to produce a quick rate of response
• To a degree, the larger the ratio requirement, the
quicker the rate of response.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Variable Ratio (VR) Schedule Effects
Responses
A = High steady rate of responding
B = Reinforcement delivered after a varying
number of required responses are emitted
A
Schedule Effects:
B
Time
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Ratio requirements are completed with a very
high rate of response and little hesitation
between responses. Postreinforcement
pauses are not a characteristic of the VR
schedule. Rate of response is influenced by
the size of the ratio requirements
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Fixed Interval (FI)
– Provides reinforcement for the first correct
response following a fixed duration of time.
– Elapse of time alone is not sufficient for
reinforcer delivery.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Fixed Interval (FI) Schedule Effects
– Consistency of Performance
• Typically produce a postreinforcement pause
• Gradually accelerating rate of response toward the
end of the interval is called an FI scallop
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Fixed Interval (FI) Schedule Effects
– Rate of response
• Tend to produce a slow to moderate rate of
response
• To a degree, the larger the fixed interval
requirement, the longer the postreinforcement
pause
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Fixed Interval (FI) Schedule Effects
A = Postreinforcement pause
B = increase in response rates as
interval progresses and reinforcer
becomes available
Responses
B
C = reinforcer delivered contingent
on first correct responses after
interval
A
Schedule Effects:
C
Time
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
FI schedules generate slow to
moderate rates of responding with
a pause in responding following
reinforcement. Responding begins
to accelerate toward the end of the
interval.
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Variable Interval (VI)
– Provides reinforcement for the first correct
response following the elapse of variable
durations of time
– “Average” amount of time
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Variable Interval (VI) Schedule Effects
– Consistency of Performance
• Tends to produce a constant, stable rate of
response.
• Typically produces few hesitations between
responses.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Variable Interval (VI) Schedule Effects
– Rate of responding
• Tends to produce low to moderate rate of
response.
• The larger the average interval, the lower the
overall rate of response
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Basic Schedules of Reinforcement
• Variable Interval (VI) Schedule Effects
A = Steady response rate; few, if any,
postreinforcement pauses
Responses
B = Reinforcer delivered
A
Schedule Effects:
B
Time
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
A VI schedule generates a slow to
moderate response that is constant and
stable. There are few, if any,
postreinforcement pauses with VI
schedules
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Thinning Intermittent
Reinforcement
• One of two methods commonly used:
– Gradually increasing the response ratio or the
duration of the time interval
– Providing instructions such as rules,
directions and signs to communicate the
schedule of reinforcement.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Thinning Intermittent
Reinforcement
• Ratio Strain
– A result of abrupt increases in ratio
requirements
– Characteristics include: avoidance,
aggression, and unpredictable pauses in
responding
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Schedules of Differential Reinforcement of
Rates of Responding
– Provides an intervention for behavior
problems associated with rate of response.
– Variation of ratio schedules
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Schedules of Differential Reinforcement of
Rates of Responding
– Differential reinforcement of high rates (DRH)
• Reinforcement of responses higher than a
predetermined criterion.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Schedules of Differential Reinforcement of
Rates of Responding
– Differential Reinforcement of Low Rates
(DRL)
• Responses are reinforced only when they are
lower than the criterion.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Schedules of Differential Reinforcement of
Rates of Responding
– Definitions
• Reinforcement is available only for responses that
are separated by a given duration time
• Sometimes referred to as Spaced-responding DRH
or Space-responding DRL
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Schedules of Differential Reinforcement of
Rates of Responding
– Full Session DRH
• Provides reinforcement if the total number of
responses during the session meets or exceeds a
number criterion
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Schedules of Differential Reinforcement of
Rates of Responding
– Full Session DRL
• Provides reinforcement if the total number of
responses during the session is at or below a
number criterion
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Schedules of Differential Reinforcement of
Rates of Responding
– Interval definition for DRH & DRL
• Reinforcement is available only for responses that
occur at a minimum or better rate of response over
short durations of time during the session.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Schedules of Differential Reinforcement of
Rates of Responding
– Differential Reinforcement of Diminishing
Rates (DRD)
• Provides reinforcement of responses at the end of
a pre-determined teim interval when the number of
respones is less than a criterion that is gradually
decreased across time intervals based on the
individuals performance.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Progressive Schedules of Reinforcement
– Systematically thins each successive
reinforcement opportunity independent of the
participant’s behavior.
• Progressive Ratio Schedules of Reinforcement
(PR)
• Progressive Interval Schedules of Reinforcement
(PI)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Progressive Schedules of Reinforcement
– Using Progressive Schedules for Reinforcer
Assessment
• Provide an assessment procedure for identifying
reinforcers that will maintain treatment effects
across increasing schedule requirements.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Variations on Basic Intermittent
Schedules of Reinforcement
• Progressive Schedules of Reinforcement
– Using Progressive Schedules for Intervention
• Systematically increasing the ratio or interval
requirements for reinforcement
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Compound Schedules of
Reinforcement
• Combined elements of continuous
reinforcement (CRF), the four intermittent
schedules of reinforcement (FR, VR, FI,
VI), differential reinforcement of various
rates of responding (DRH, DRL), and
extinction (CRF)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Compound Schedules of
Reinforcement
• Concurrent Schedule of Reinforcement
(conc)
– Occurs when (a) two or more contingencies of
reinforcement (b) operate independently and
simultaneously (c) for two or more behaviors.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Compound Schedules of
Reinforcement
• Concurrent Schedule of Reinforcement
(conc)
– Using Concurrent Schedules for Reinforcer
Assessment
• This schedule requires the participant to choose
between two or more stimuli rather than indicating
a preference for a given stimulus.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Compound Schedules of
Reinforcement
• Concurrent Schedule of Reinforcement
(conc)
– Using Concurrent Schedules for Intervention
• Arranging two or more reinforcers for the
participant to choose from contingent upon the
occurrence of a target behavior.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Compound Schedules of
Reinforcement
• Concurrent Performances: Formalizing the
Matching Law
– Concurrent interval schedules – participants
typically do not allocate all of their responses
exclusively to the richer schedule.
– Concurrent ratio schedules – participants are
sensitive to the ratio schedules an tend to
maximize reinforcement by responding
primarily to the ratio that produces the higher
rate of reinforcement.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Compound Schedules of
Reinforcement
• The Matching Law
– Rate of responding typically is proportional to
the rate of reinforcement received from each
choice alternative.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Discriminative Schedules of
Reinforcement
• Multiple Schedules of Reinforcement
(mult)
– Presents two or more basic schedules of
reinforcement in an alternating, usually
random, sequence.
– Basic schedules occur successively and
independently.
– A discriminative stimulus is correlated with
each basic schedule and is present as long as
the schedule is in effect
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Discriminative Schedules of
Reinforcement
• Chained Schedules of Reinforcement
(chain)
– Similar to (mult)
– Differs in three ways –
• Basic schedules occur in a specific order
• The behavior may be the same for all elements of
the chain, or different behaviors may be required
for different elements
• Conditioned reinforcement for first behavior in the
chain is the presentation of the second element
and so on.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Non-discriminative Schedules of
Reinforcement
• Mixed Schedules (mix)
– Identical to multiple schedules, except the
mixed schedule has no discriminative stimuli
correlated with the independent schedules
– Example: mix FR 10 FI 1 schedule
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Non-discriminative Schedules of
Reinforcement
• Tandem Schedules
– Similar to the chained schedule except the
tandem schedule does not use a
discriminative stimulus
– Example: FR 15 FI 2 schedule – participants
makes 15 responses then reinforcement is
delivered for the first response after 2 minutes
of elapsed time.
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved