Recent Innovations in the Changing Criterion Design: Implications for Research and Practice in Special Education

This article illustrates (a) 2 recent innovations in the changing criterion research design, (b) how these innovations apply to research and practice in special education, and (c) how clinical needs influence design features of the changing criterion design. The first innovation, the range-bound changing criterion, is a very simple variation of the classic changing criterion design. The classic version uses a single criterion for each stepwise intervention phase, whereas the range-bound version uses a range criterion--that is, an upper and lower limit for each intervention phase. The second innovation, the distributed criterion, combines elements of the changing criterion, multiple-baseline, and ABAB designs. It is well suited to contexts where students must multitask--that is, allocate, prioritize, and adjust time and effort to complete multiple tasks in response to changing environmental demands. These two innovations expand options available to researchers who use single-case research designs to investigate questions of interest in special education.