Shaping to Teach New Behaviors

Description of the Strategy

Positive reinforcement refers to any stimulus presented after the occurrence of a behavior that increases the future occurrence of the behavior. Shaping is a powerful means for encouraging the performance of a newly learned behavior and maintaining occurrences at high levels through the use of intermittent schedules of reinforcement. Most behaviors consist of complex steps that must be mastered before the terminal goal can be reached. For example, this process can be observed in a student learning to write. He must first become proficient at holding a pencil before he is able to make letters. Once the student can hold the pencil with the correct grip, he can begin to move the pencil to make letters on a piece of lined paper. The student then may write so that upper-case letters touch the top of the lines on the paper and lower-case letters stop halfway to the top of the lines. If he goes outside of the lines, he may either erase the letter or repeat the process of writing it correctly. Eventually, the student will master writing multiple letters together to form words. The terminal behavior is to write words in cursive rather than printing.

Shaping is the process of reinforcing successively closer approximations of the target behavior. It involves breaking down the desired behavior into its subcomponents and providing reinforcement for the [Page 1517]performance of each step or combination of steps toward the final behavior, The process cannot be said to be occurring without a physical change taking place in a person's behavior, that is, a change in the typography of the behavior. The student's behavior in the previous example changes from initially holding a pencil to eventually writing words in cursive.

Shaping has not occurred when the change is in the response rate. For example, if the goal is to increase accurate completion of a 25-problem multiplication worksheet, reinforcement might be presented when the first 5 problems are completed, then for completion of 10 problems, then 15, 20, and then all 25 problems. Shaping also has not transpired when behavior changes without differential reinforcement. For example, for students who are chronically 10 minutes late to class, reinforcement might be presented for being only 7 minutes late, then 5, 3, 1 minute late, and then for being on time. Shaping did not take place because reinforcement was presented for performing the same behaviors—walking into the classroom and sitting down. The only change was the time. The use of reinforcement can be a powerful tool to increase assignment completion and being on time to class, but these are not examples of shaping.

Shaping often occurs naturally because much of what humans do builds on a simple beginning behavior. For example, learning to play a piano begins with the simple behaviors of pressing the keys that correspond to the scale and progressing until the learner may play complex chords and notes that become complete songs and scores. Students learning to play basketball in physical education provide another example. Students begin with learning to make a simple lay-up and gradually learn reverse lay-ups and jump shots. This is an example of natural, or variableoutcome, shaping. The reinforcer may have been the student making a basket. The natural environment shaped more and different types of movements to accomplish this goal. This type of shaping is in contrast to an adult administering reinforcement every time a student makes a successive step toward the terminal behavior (fixed-outcome shaping).

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