What is Shaping? A process where you systematically and differentially reinforce successive...

What is Shaping?A process where you systematically and

differentially reinforce successive approximations to a desired behavior

Used to help learners acquire new behaviors

Differential ReinforcementSome members of a response class are

reinforced (responses that are successively closer to the terminal behavior)

Other members of that response class are not reinforced (responses that are not closer to the terminal behavior)

Response DifferentiationInvolves two components:

Differentially reinforce behaviors that resemble the terminal behavior

Carefully changing the criterion for reinforcement

ResultIncrease in behaviors successively closer to

terminal behaviorDecrease in behaviors that are not

successively closer to terminal behavior

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Walk to sink and look at it

SR+

Cold water presented

Walking to sink and looking at it maintains

EO

Deprived of water for a long period

of time

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:

Response already in repertoire

Cooper, Heron, and HewardApplied Behavior Analysis, Second Edition

Copyright © 2008 by Pearson Education, Inc.All rights reserved

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Walk to sink and look at it

SO

Cold water withheld

Walking to sink and looking at it when deprived of water decreases

EO

Deprived of water for a long period

of time

Shaping step 1:

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Point to tap

SR+

Cold water presented

Pointing to tap when deprived of water increases

EO

Deprived of water for a long period

of time

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Point to tap

SO

Cold water withheld

Pointing to tap when deprived of water decreases

EO

Deprived of water for a long period

of time

Shaping step 2:

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Touch tap

SR+

Cold water presented

Touching tap when deprived of water increases

EO

Deprived of water for a long period

of time

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Touch tap

SO

Cold water withheld

Touching tap when deprived of water decreases

EO

Deprived of water for a long period

of time

Shaping step 3:

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Grasp tap

SR+

Cold water presented

Grasping tap when deprived of water increases

EO

Deprived of water for a long period

of time

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Grasp tap

SO

Cold water withheld

Grasping tap when deprived of water decreases

EO

Deprived of water for a long period

of time

Shaping step 4:

SD

Tap on faucet

marked with blue dot or letter “C”

Response

Turn tap

SR+

Cold water presented

Turning tap when deprived of water increases

EO

Deprived of water for a long period

of timeTerminal Behavior

Dimensions of Behavior that can be ShapedTopography

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

Guidelines for Implementing ShapingConsider Nature of Behavior to be Learned and

Resources AvailableSelect the Terminal BehaviorDetermine Criteria for SuccessAnalyze the Response ClassEliminate interfering StimuliDeprivation of Reinforcers you want to useIdentify the First Behavior to ReinforceLimit the Number of Approximations at Each

LevelContinue Reinforcement when Terminal

Behavior is Achieved

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

Select the Terminal BehaviorThe 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 preciselyThen you’ll know when the behavior has

occurred

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

Analyze the Response ClassIdentify the approximations that might be

emitted during training BEFORE TRAINNG BEGINSTrainer is in a better position to “stay ahead

of his/her subject”Can be done by:

Consulting experts in the fieldUse published literatureUse videotape of peers to analyze

components of a behaviorPerform the target behavior yourself

LIST THEM IN ORDER

16

Key to Shaping - DeprivationIf possible, deprive the organism of what you

want to reinforce it with.

Animals with food. Deprive to 80% of its body weight.

Deprive kid of reinforcer you want to use.

17

KidsFood

Chocolate Chip Cookies (ccc’s)M & Ms

TokensMoney

Identify the First Behavior to Reinforce Behavior should already occur at some levelBehavior should be a member of the targeted

response class

SpecificsEliminate Interfering Stimuli

Eliminate distractions during trainingProceed in Gradual Stages

Be prepared for decrements in performance when you increase criteria

Limit the Number of Approximations at Each LevelLest 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

Move to a schedule of reinforcementThin the schedule

Increasing Efficiency of ShapingCombine with other discriminative stimuli

(e.g., a prompt)Verbal cuesPhysical guidanceModels

Positive Aspects of ShapingTeaches new behaviorsIs a positive approach to teachingCan be combined with other procedures,

such as chaining, imitation, etc.

Limitations of ShapingCan be time consumingProgress is not always linear and may be

erraticRequires a skillful trainer, who can

recognize subtly closer approximationsCan be misapplied (problem or harmful

behaviors can be accidentally shaped)

24

Reverse ShapingIs different from Regular Shaping Start at the end response, then reinforce it.

Then two steps before you reinforce it,

Then three steps, etc.

25

ExamplesTeaching a kid to tie their shoes.

SummaryIs an extremely useful techniqueCan be used with a variety of other techniquesCan be used to change behaviorWe use shaping with many behaviors and do not

know itCan be used systematically to manipulate behavior

of others in a variety of situationsWeight control Business relationshipsFamily relationships

Can take longer than other techniques.