Changing Criterion Design

The changing criterion design (CCD) is a single-case experimental method in which a behavior is gradually shaped toward a terminal goal through a series of stepwise performance criteria. Instead of expecting a behavior to leap from baseline to its final target, the analyst sets an initial subgoal, reinforces performance that meets it, and then ratchets the criterion up (or down) once behavior stabilizes at each step. Experimental control is demonstrated when the behavior repeatedly and closely tracks each successive criterion change — changing only when, and to the degree that, the criterion changes — so that each new step functions as another demonstration of effect. The design is especially well suited to behaviors that should change incrementally, such as increasing exercise tolerance, reducing cigarettes smoked, or building a new skill in graded approximations. It belongs to the single-case design family codified by Kratochwill and colleagues in 2013, sharing their requirements for systematic manipulation and replicated demonstrations of effect.