Changing Criterion Design

The changing criterion design (CCD) is part of a compendium of research methods commonly referred to as single-case or small-n designs. Differing slightly from other single-case designs (SCDs), the goal of the CCD is to gradually increase or decrease the rate at which a single target behavior occurs. CCDs accomplish this goal by implementing a series of phases, each with a stepwise change in the rate of the target behavior required to meet the phase’s criterion. Each phase can then be used as the subsequent phase’s baseline. This entry details a brief history of the CCD, its experimental rigor, its defining features, and its common applications.