Shaping & Chaining
Behavior
8-19-13
Malott, R. (2008) Principles of Behavior.
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Shaping Behavior
Malott, R. (2008) Principles of Behavior.
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Example
• Andrew entered Big State Hospital when he was 21
• From the day he entered, he didn’t say a word – 19
years of silence
• He attended Dawn’s group therapy session with
patients who did speak
• In one session Dawn accidentally dropped a stick of
chewing gum from her purse
• Andrew showed interest in the gum
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Andrew
• In the next group session, Dawn held the gum in
front of Andrew’s face and waited until he looked at
it
• Then she immediately gave him the gum
• After 2 weeks, he reliably looked at the gum when
she held it in front of his face
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Next Step
• Dawn waited until Andrew moved his lips slightly
before giving him the gum
Before
Andrew has no
gum
Behavior
Initial:
Andrew moves his
lips
After
Andrew has gum
• After he was doing this reliably, she waited until he
made a sound before giving him the gum
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Differential Reinforcement
Behavior
Intermediate:
Andrew makes
croaking sound
After:
Andrew has gum
Before:
Andrew has no gum
Behavior
After:
Intermediate:
Andrew moves his
lips
Andrew has no gum
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Terminal Behavior
• Then Dawn prompted him to say “gum gum”
• His croaking sound faintly resembled “gum”
• Dawn immediately reinforced this response
• She then reinforced closer and closer
approximations to the word “gum”
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Differential Reinforcement
Behavior
Terminal:
After:
Andrew says gum
Andrew has gum
Before:
Andrew has no gum
Behavior
After:
Intermediate:
Andrew makes
croaking sound
Andrew has no gum
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Results
• Andrew clearly said, “Gum, please,” after 6 weeks of
this intervention.
• After that day he would answer any question Dawn
asked.
• He also chatted with his nurse outside of therapy
sessions.
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Analysis
• Because he didn’t talk, everyone assumed he
couldn’t.
• So they interpreted his gestures and signs.
• When 2 responses produce the same reinforcers, we
tend to do the one needing the least effort.
• But the contingencies changed when Dawn required
more and more effortful vocal and verbal behavior
before she delivered the reinforcer.
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Shaping with Reinforcement
Operant Level:
• The frequency of responding before reinforcement.
Terminal Behavior:
• Behavior not occurring in the repertoire or not
occurring at the desired frequency; the goal of the
intervention.
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What is Initial Behavior?
Initial Behavior:
•
Behavior that resembles the terminal behavior
•
along some meaningful dimension
•
and occurs at least with a minimal frequency.
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What is Intermediate Behavior?
Intermediate Behavior:
• Behavior that more closely approximates the
terminal behavior.
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So What is Shaping with
Reinforcement?
Shaping with Reinforcement:
• The differential reinforcement of only the behavior
• that more and more closely resembles the terminal
behavior.
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When do you use shaping?
• When you want to bring about new responses.
• Reinforce the initial behavior until it occurs
frequently.
• Then abandon that response.
• Select and differentially reinforce another response
that approximates the terminal behavior.
• Continue until the terminal behavior occurs, and
reinforce it until it occurs frequently.
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Shaping Reinforcement
Behavior
Initial:
Andrew moves lips
Intermediate:
Makes croaking sound
Terminal:
Says words clearly
After:
Andrew has gum
Before:
Andrew has no gum
Behavior
Initial:
Not applicable
Intermediate:
Moves lips only
Terminal:
Says words unclearly
After:
Andrew has no gum
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Example
• Dicky, a boy with autism, needed glasses.
• The glasses were aversive for Dicky, and he would
not wear them.
• Mont Wolf and his team of behavior analysts spent 23 20-minute sessions with Dicky in his room.
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Procedure
• They reinforced Dicky’s carrying his glasses,
• bringing them closer and closer toward his face,
• and actually putting them on.
• A gradual shaping process.
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Shaping Reinforcement
Behavior
Initial:
Carries glasses
Intermediate:
Glasses near face
Terminal:
Puts on glasses
After:
Dicky has fruit or candy
Before:
Dicky has no candy or
fruit
Behavior
Initial:
Not applicable
Intermediate:
Only carries glasses
Terminal:
Glasses only near face
After:
Dicky has no candy or
fruit
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Is wearing glasses a behavior?
• No.
• It fails the dead man test.
• So we talk about putting the glasses on or taking
them off.
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Results
• After 30 minutes of shaping, Dicky was putting on
the glasses properly and looking through the lenses
at various toys.
• Soon he put his glasses on any time they requested.
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Example
• 13-year old Melanie was aphonic.
– She spoke in a low, raspy whisper
• Behavior analysts used praise to shape the loudness
of her vocal responses.
• First they shaped breathing, then humming, then
saying consonants, then reading, and finally
conversing.
• They helped her speak loudly and clearly.
• During a 2-year follow up they realized her vocal
responses were still loud and clear.
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Shaping with Reinforcement
Behavior
Initial:
Converses lightly
Intermediate:
Converses moderately
Terminal:
Converses loudly
After:
Melanie gets praise
Before:
Melanie gets no praise
Behavior
Initial:
Converses very lightly
Intermediate:
Converses lightly
Terminal:
Converses Moderately
After:
Melanie gets no praise
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Teaching Behavior Chains
Malott, R. (2008) Principles of Behavior.
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Example
• Nancy had cerebral palsy
• She was 5 years old, and had never walked, run, or
stood
• She did rise to her knees from time
to time
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What did the behavior analysts do to
help Nancy?
•
They did a task analysis of walking
1. Nancy had to rise to her knees
2. Then rise to her feet
3. Then walk with a crutch
•
This is a behavioral chain
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Intervention
• Dawn began reinforcing Nancy rising to her knees
• After she was reliably rising to her knees, Dawn only
reinforced Nancy pulling herself to her feet
• Then walking a few steps while holding onto a
cabinet
• Then she gave Nancy a harness to support her while
she walked
• She gradually reduced the support she gave Nancy
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Results
• Nancy was walking!
• Dawn reduced the reinforcers
• Finally, the normal reinforcers that
reinforce walking were maintaining
Nancy walking
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Behavioral Chain
SD
Nancy
stands
Behavior
Sr/SD
Moves left
food
Foot forward
Behavior
Sr/SD
Leans
forward
Body
forward
Behavior
Raises
crutch
Sr/SD
Nancy’s
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crutch up
What is a Behavioral Chain?
Behavioral Chain:
• A sequence of stimuli and responses
• Each response produces a stimulus that
• reinforces the preceding response
• and is an SD or operandum
• for the following response.
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Example
MO
Sight of
potatoes
Behavior
Pick up fork
Sr/Oper.
Fork in hand
Behavior
Put fork in
potato
Sr/SD
Fork in
potato
Behavior
Raise fork
Sr/SD
Fork raised
Behavior
Put potato in
mouth 32
What are Dual-Functioning Chained
Stimuli?
Dual-Functioned Chained Stimuli:
• A stimulus in a behavioral chain
• reinforces the response that precedes it
• and is an SD or operandum for the following
response.
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Example
• The sight of the potatoes is a stimulus in the
presence of which we pick up our fork.
• The sight and feel of the fork reinforced picking it up
• .
• But at the same time,
• the sight and feel of the fork also functions as an SD
in the presence of which moving your hand near the
potatoes will be reinforced.
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And…
• The sight and feel of the fork in the potatoes
• reinforced moving the fork toward the potatoes.
• At the same time,
• the fork in the potatoes is an SD for raising them to
your mouth.
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What is Forward Chaining?
Forward Chaining:
• The establishment of the first link in a behavioral
chain,
• with the addition of successive links,
• until the final link is acquired.
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Example
• Dawn taught Nancy to walk using forward chaining.
• First she trained the first link in the chain (rising to
knees),
• then she trained the next link (rising to feet),
• then finally she trained the final link in the chain
(walking).
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What is Total-Task Presentation?
Total-Task Presentation:
• The simultaneous training of
• all links in a behavioral chain.
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Example
• Teaching adolescents with disabilities to brush their
teeth.
• The learners performed each of the 15 links in the
behavioral chain of brushing teeth before starting
over again.
• The learner didn’t master one link before proceeding
to the next one.
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Procedure
• The trainer told the learner to do the response in one
of the links.
• If that didn’t work, the trainer would model the
response and maybe give physical guidance,
• then they’d move to the next link in the chain.
• The trainer praised the client each time he completed
the response in a link of the chain (e.g., removing
cap from the tube).
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What is Backward Chaining?
Backward Chaining:
• The establishment of the final link in a behavioral
chain,
• with the addition of preceding links
• until the first link is acquired.
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Example
• Arithmetic
• First, do a task analysis of the process of multiplying
2 numbers.
• Each response and the resulting number you write
down is a link in the chain.
• Completed Problem:
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X 23
126
+ 840
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???
Arithmetic Example
• The final links are adding 126 + 840 and then writing
down 966.
• Then move backward to this set of links:
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X 24
124
+ ???
???
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Arithmetic Example
• After the students have successfully gone through a
number of problems involving these last 2 links in
the chain,
• they’re ready for problems involving the whole
chain, starting with the first link:
67
X 89
???
+ ???
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???
Practice Behavior Chains
• In a small group, create a task analysis for a skill
(provided)
• Determine whether you will use forward chaining,
backward chaining, and/or total task presentation to
teach your skill
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