Which experimental design uses an initial baseline phase followed by a series of treatment phases with gradually changing criteria for reinforcement or punishment?

• A. Multielement Design
• B. Changing Criterion Design
• C. ABAB Design
• D. Alternating Treatments Design

Answer: (B)

Changing Criterion Design starts with a stable baseline of the target behavior, then introduces treatment phases in a sequence where the reinforcement (or punishment) criteria are systematically changed across phases. Each new phase shifts the criterion so the behavior must meet progressively stricter (or sometimes looser) requirements in order to earn reinforcement. When the behavior changes in concert with those criterion shifts, it provides clear evidence that the reinforcement contingencies are controlling the behavior, demonstrating a functional relation between the criterion and the response. This gradual shaping through successive criteria is what distinguishes this design.

The other designs operate in different ways, such as comparing several treatments rapidly without a gradual criterion shift, or alternating baseline and treatment periods to show control, rather than gradually changing reinforcement thresholds to induce behavior change.