Transcript Document

Chapter 19:
Shaping
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
What is Shaping?
• A process in which one
– Systematically and differentially reinforces
– Successive approximations to a terminal
behavior
• Used to help learners acquire new
behaviors
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Differential Reinforcement
• Some members of a response class are
reinforced (responses that are
successively closer to the terminal
behavior)
• Other members of that response class
(responses that are not closer to the
terminal behavior)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Response Differentiation
• Involves two components:
– Differentially reinforce behaviors that resemble the
terminal behavior
– Carefully changing the criterion for reinforcement
• Result
– Increase in behaviors successively closer to
terminal behavior
– Decrease in behaviors that are not successively
closer to terminal behavior
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Shaping Diagrammed
 Assume we want to teach a child to turn on the cold water tap in order to get
a drink of water.
 Assume the child already walks to sink and looks at it when he/she is thirsty.
 Shaping might proceed like this:
EO
SD
Response
SR+
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Walk to
sink and
look at it
Cold water
presented
Walking to sink
and looking at it
maintains
Response already in
repertoire
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2008 by Pearson Education, Inc.
All rights reserved
Shaping Diagrammed
 Shaping step 1:
EO
SD
Response
SO
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Walk to
sink and
look at it
Cold water
withheld
EO
SD
Response
SR+
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Point to
tap
Cold water
presented
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Walking to sink
and looking at it
when deprived of
water decreases
Pointing to tap
when deprived of
water increases
Copyright © 2008 by Pearson Education, Inc.
All rights reserved
Shaping Diagrammed
 Shaping step 2:
EO
SD
Response
SO
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Point to
tap
Cold water
withheld
EO
SD
Response
SR+
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Touch tap
Cold water
presented
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Pointing to tap
when deprived of
water decreases
Touching tap
when deprived of
water increases
Copyright © 2008 by Pearson Education, Inc.
All rights reserved
Shaping Diagrammed
 Shaping step 3:
EO
SD
Response
SO
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Touch tap
Cold water
withheld
EO
SD
Response
SR+
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Grasp tap
Cold water
presented
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Touching tap
when deprived of
water decreases
Grasping tap
when deprived of
water increases
Copyright © 2008 by Pearson Education, Inc.
All rights reserved
Shaping Diagrammed
 Shaping step 4:
EO
SD
Response
SO
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Grasp tap
Cold water
withheld
EO
SD
Response
SR+
Deprived of
water for a
long period
of time
Tap on
faucet
marked with
blue dot or
letter “C”
Turn tap
Cold water
presented
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Grasping tap
when deprived of
water decreases
Terminal
Behavior
Turning tap when
deprived of water
increases
Copyright © 2008 by Pearson Education, Inc.
All rights reserved
Dimensions of Behavior that
can be Shaped
• Topography
– Form of the behavior
• Frequency
– Number of responses per unit of time
• Latency
– Time between onset of antecedent stimulus and the occurrence of
the behavior
• Duration
– Total elapsed time for the occurrence of the behavior
• Amplitude
– Magnitude
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Successive Approximations
• An intermediate behavior
– Prerequisite for terminal behavior or
– Higher order member of the same
response topography
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Shaping Across and Within
Response Topographies
• Across response topographies
– Topography of behavior changes during
shaping
– Behaviors are still members of the same
response class
• Within response topographies
– Topography of behavior remains constant
– Another measurable dimension of behavior
is changed (e.g., duration of the behavior)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Positive Aspects of Shaping
• Teaches new behaviors
• A positive approach to teaching
• Can be combined with other
procedures, such as chaining
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Limitations of Shaping
• Can be time consuming
• Progress is not always linear and may
be erratic
• Requires a skillful trainer, who can
recognize subtly closer approximations
• Can be misapplied (problem or harmful
behaviors can be accidentally shaped)
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Shaping vs. Fading
• Both change behavior gradually
– Shaping via changing response
requirements
– Fading by changing antecedent stimuli
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Increasing Efficiency of
Shaping
• Combine with a discriminative stimulus
(e.g., a prompt)
– Verbal cues
– Physical guidance
– Models
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Guidelines for Implementing
Shaping
• Consider nature of behavior to be
learned and resources available
– How far away is current performance from
terminal behavior?
• This might influence how long shaping will take
– What is the availability of staff and other
resources?
• Remember, this is a labor intensive procedure
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Guidelines for Implementing
Shaping
• Select the Terminal Behavior
– The ultimate criterion for selecting a
behavior for change:
• How will the behavior change contribute to the
learner’s independence in gaining
reinforcement?
– Define the terminal behavior precisely
• Then you’ll know when the behavior has
occurred
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Guidelines for Implementing
Shaping
• Determine Criteria for Success
– How accurate, fast, long, or intensely
should the behavior be performed? Under
what conditions should it be performed?
– Establish norms by
• Consulting literature
• Observing similar peer group
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Guidelines for Implementing
Shaping
• Analyze the Response Class
– Identify the approximations that might be
emitted during training
• Trainer is in a better position to “stay ahead of
his/her subject”
– Can be done by:
• Consulting experts in the field
• Use published literature
• Use videotape of peers to analyze components
of a behavior
• Perform the target behavior yourself
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Guidelines for Implementing
Shaping
• Identify the First Behavior to Reinforce
– Behavior should already occur at some
level
– Behavior should be a member of the
targeted response class
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Guidelines for Implementing
Shaping
• Eliminate Interfering Stimuli
– Eliminate distractions during training
• Proceed in Gradual Stages
– Be prepared for decrements in
performance when you increase criteria
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved
Guidelines for Implementing
Shaping
• Limit the Number of Approximations at
Each Level
– Lest the behavior become too firmly
established
• Continue Reinforcement When the
Terminal Behavior is Achieved
– The behavior will be lost if the terminal
response is not reinforced
Cooper, Heron, and Heward
Applied Behavior Analysis, Second Edition
Copyright © 2007 by Pearson Education, Inc.
All rights reserved