ABA glossary
Shaping
Definition
Teaching a new behavior by differentially reinforcing successive approximations of it, each closer to the terminal behavior, while withholding reinforcement for earlier forms.
In plain words
Shaping builds behavior the learner cannot yet do by reinforcing small steps toward it. You start with something the learner already does that resembles the goal, reinforce it, and then raise the requirement: only a closer approximation earns reinforcement, and the earlier form no longer does. Over time the behavior moves step by step to the final form. Shaping can change the form of a behavior (a sound becoming a word) or a dimension of it (sitting for 5 seconds, then 10, then 30).
Example from a session
Ben's goal is to say "bubble." At first any vocal sound while looking at the bubbles earns a few bubbles; then only "buh"; then "buh-buh"; then "bubble." When Ben says "buh" after the criterion has moved to "buh-buh," the RBT waits for a closer try instead of blowing bubbles. She records the current step and moves on only when the data meet the plan's criterion.
For BCBA candidates and supervisors
Effective shaping depends on choosing the right starting point, step size, and number of reinforcers at each step: steps too large produce extinction-like effects (errors, frustration, problem behavior), and staying too long at one step makes that approximation hard to move past. Analysts write shaping plans with clear criteria for moving forward and backward. Shaping can be combined with prompting to speed progress. Problem behavior can also be shaped unintentionally, as when caregivers give in only to louder or longer episodes, gradually reinforcing more intense behavior.
Often confused with behavior chain, stimulus fading
Shaping changes one behavior into a new form or level through successive approximations. Chaining links several different responses into a sequence, each step cueing the next. Stimulus fading changes the antecedent (the materials or cues), while shaping changes the response requirement.
Exam tip
If the stem describes reinforcing closer and closer versions of the same behavior, it is shaping. If it describes teaching the steps of a routine in order, it is chaining. "Differential reinforcement of successive approximations" is the standard phrase.
Can you spot shaping in a scenario?
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