Shaping

The following information is from Unit 7 of the book Teaching: A Course in Psychology by Wesley C. Becker, Siegfried Engelmann, and Don R. Thomas. 

Note: Science Research Associates published the book in 1971. I am unsure if the publishers reprinted the book or if it is available to buy. I found it through a university inter-library loan program. I suspect that Becker or Engelmann use the book or some form of it in their special education teaching classes at the University of Oregon.

• Shaping: reinforcement and extinction used together to build new behavior
• Differential reinforcement: responses meet a certain criteria to be reinforcement
• Responses that do not meet the criteria are not reinforced
• Shifting criteria for reinforcement: reinforced responses are gradually changed so the the learner eventually shows the behavior you want

• Example of shaping: a patient in an institution hoarded towels, ate too much food and was overweight, and wore too much clothing
• First a behaviorist told the nurse to remove her from the dining room without food if she stole any food
• She only stole 6 times in the next 60 weeks and her weight changed from 250 to 180 pounds
• Then the behaviorist kept giving her towels in her room
• She ended up being satiated on the towels because she could not fold and stack them all
• She helped remove the towels on her own and no longer wanted to hoard
• Then the behaviorist determined that she tended to wear 25 extra pounds of clothing
• She would be allowed to enter the dining room if she weighed her weight plus 23 pounds (wearing 2 pounds less)
• If she removed more clothes than they asked for so she could enter the dining room, they lowered the weight requirement for next time
• Over 11 weeks she was allowed to enter the dining room if she weight her weight plus 3 pounds
• She also started to participate in social events at the institution and was allowed to visit her home for the first time in 9 years

• How to shape

1. Define the target behavior
1. Example: Jimmy will do 20 addition problems (specific amount) in 20 minutes (specific time) without asking the teacher for help
2. Decide what behavior you are building from
1. Example: Jimmy will do 1 problem in 2 minutes with the teacher available to help
3. Establish a reinforcer
1. He will earn points on a card and for every 25 points he earns, he chooses a game at recess
4. Outline the program of steps to get to the target behavior
1. Jimmy is given problems that are not too difficult for him
2. He is given a paper with 1 problem on it
1. Teacher helps
3. He is given a paper with 1 problem on it
1. Teacher tells him to do this one himself and she’ll come back when he indicates he finishes by raising his hand
4. He is given a paper with 2 problems on it
1. Teacher tells him to do these himself and she’ll come back when he indicates he finishes by raising his hand
5. He is given a paper with 5 problems on it
1. Teacher tells him to do these himself and she’ll come back when he indicates he finishes by raising his hand
6. He is given a paper with 10 problems on it
1. Teacher tells him to do these himself and she’ll come back when he indicates he finishes by raising his hand
7. He is given a paper with 15 problems on it
1. Teacher tells him to do these himself and she’ll come back when he indicates he finishes by raising his hand
8. He is given a paper with 20 problems on it
1. Teacher records how long it takes for him to do the 20 problems
9. He is given another paper with 20 problems on it
1. Teacher tells him if he can finish the paper in less than X minutes he will get 5 extra bonus points
2. X is 1 minute less than the time measured on the first 20 problem paper
10. Continue given papers in this fashion until papers are completed in less than 20 minutes and slowly lower the time requirement
5. Start the shaping with first criterion for reinforcement
1. Jimmy does the 1 problem page and is immediately reinforced
6. Shift to each new criterion for reinforcement as soon as the previous criterion is met
7. If the criterion is not met, return to an earlier step or add a new step
1. If Jimmy cannot finish 10 problems without help, return him to 5 problems
2. Then increase the problems to 8 instead of 10
8. Repeat steps 6 and 7 until the target behavior is achieved
1. Jimmy finishes 20 problems without help in under 20 minutes

• Shaping requirements
• Know what you want the child to do
• Know what steps you need to get there
• Make decisions during the steps if you go ahead or go back
• Do not stay too long at one step or time is lost and the wrong behaviors will be reinforced
• Do not move too quickly or the child will lose motivation when he is not meeting reinforcement criterion

• Shaping at school
• Some responses that may need shaping at school
• Working persistently
• Working quicker
• Paying attention
• Staying in your seat
• Talking at the appropriate level
• Writing in manuscript or cursive
• Physical education skills
• Shaping is inefficient compared to prompting
• Shaping should be used when there are no prompts to motivate the target behavior
• Example: you can’t say “sit and work hard for an hour and I’ll give you a treat” if the student has never worked for more than 5 minutes before
• Do not get in the pattern of shaping (accepting poor answers) when it is not necessary
• Use prompting or imitation for most target behaviors
• Classroom rules can help to prompt desired behavior
• Do not reinforce misbehavior by giving it attention and ignore good behavior

• Example of shaping without verbal instructions
• A monkey was shaped to press a response button within 1 second after a warning tone sounded
• At first the monkey did not make a response until an average of 4 seconds
• So the first criterion for reinforcement (banana pellets) was 4 seconds
• When the monkey made responses in less than 4 seconds, the criterion was 3 seconds for reinforcement
• The criterion shifted to 2 seconds, 1.5 seconds, and 1 second