C.10 · Behavior Acquisition

Shaping and successive approximations

Follow examples of reinforcing successive approximations toward a final response. Review how the supervisor’s plan defines the current criterion and when to advance, and compare shaping with chaining a multistep routine.

Task C.10: Apply shaping procedures

Useful foundations: C.1: Positive and negative reinforcement

The rule

Shaping reinforces successive approximations to a target response, with the criterion changing as closer forms are established.

Identify the final response, the current approximation and the planned advancement rule. Shaping changes a dimension of one response; chaining teaches a sequence of component responses.

Key terms
Successive approximation
A response that meets the current step toward a more precise final target.

What to look for

DistinctionLook forHow to decide
ApproximationA response closer to the final formReinforce the currently specified approximation.
Criterion shiftThe learner meets a planned advancement thresholdMove to the next approximation as directed.
Procedure boundaryResponse form changes versus a sequence of actionsShaping differs from chaining a multistep routine.

Worked examples

Successive approximations

Build a longer sound

A supervisor’s speech-related teaching plan targets a sustained “mmm” sound for two seconds. The current criterion is any audible “mmm” lasting at least half a second. The learner produces a 0.7-second sound without help.

Relevant facts

  • The final target is two seconds.
  • The current reinforced approximation is at least 0.5 seconds.

Deliver the planned consequence for the current approximation.

0.7 seconds meets the current 0.5-second criterion; the final target is 2 seconds

Score the response against the current criterion and deliver the programmed consequence when it qualifies. This supports progress toward the final response.

Shifted criterion

Apply the updated approximation

After the documented advancement criterion is met, the same plan moves to a one-second “mmm.” The next response lasts 0.7 seconds. The plan specifies which responses now receive the teaching consequence.

Relevant facts

  • The approved current criterion is now one second.
  • The observed response lasts 0.7 seconds.

Apply the new criterion and follow the planned response to a below-criterion attempt.

0.7 seconds < current 1-second criterion

The plan now specifies a new approximation. Apply its current threshold and use the planned advancement rule for later changes.

A different approximation

Shape spatial accuracy

A supervisor’s throwing-game plan targets landing a beanbag within 10 cm of a floor marker. At the current stage, landings within 40 cm earn the planned consequence. A bag lands 25 cm away. After the advancement criterion is met, a later stage requires landing within 20 cm.

Relevant facts

  • At the current stage, 25 cm is within the 40 cm limit.
  • At the later stage, the same 25 cm landing is outside the 20 cm limit.

The landing qualifies at the current stage. The later stage uses a tighter accuracy criterion.

25 ≤ 40 cm now; 25 > 20 cm at the later stage

These approximations improve the spatial accuracy of one response. Shaping can change several response dimensions; chaining links separate actions into a routine.

What changes the answer?

Change the teaching objective.

  • Both programs build a skill gradually.

The same sound is reinforced for progressively longer durations.

Shaping.

Successive approximations change one response dimension.

Opening a pouch, adding items and zipping it are taught in sequence.

Chaining.

Distinct component responses form a routine.

Identify what changes across stages: a dimension of one response or the component steps being taught.

Remember

  • Apply the current approximation on the way to the final goal.
  • Shift criteria through the plan, with data.
Sources for this topic

Reviewed 2026-09-30 · C.10 version 3.