Experimental Design and Behavior-Change Procedures
Designs that demonstrate control
Single-case designs establish experimental control by showing that behavior changes when, and only when, the independent variable is manipulated. Reversal (ABAB) designs require a return to baseline; they are inappropriate when behavior is dangerous or irreversible. Multiple-baseline designs (across behaviors, settings, or participants) stagger intervention onset without withdrawal. Changing-criterion designs raise the criterion stepwise to shape performance. Alternating-treatments designs rapidly compare conditions to identify an effective intervention. Withdrawal and component analyses test which elements drive change. Traps: calling a simple AB comparison "experimental" (it lacks replication), or using reversal when ethical concerns preclude removal.
Behavior-change procedures
Shaping reinforces successive approximations. Chaining (forward, backward, total task) links a sequence of responses. Prompting (verbal, gestural, model, physical) and fading build independence. Differential reinforcement variants - DRA (alternative), DRI (incompatible), DRO (other), DRL (low rates) - reduce behavior by reinforcing alternatives. Extinction, response cost, and time-out are consequence-based reduction tactics. Token economies and behavioral contracts arrange conditioned reinforcement. Self-management teaches self-monitoring and self-reinforcement.
Worked example
A learner cannot complete a 10-step routine. Use backward chaining: teach the final step first, reinforce completion, then add preceding steps. Rule of thumb: choose the design that fits the ethics and reversibility of the behavior; choose the procedure that matches the function identified in assessment.