ABSTRACT
This chapter focuses on several types of comparison designs; that is, designs that allow researchers to compare two different interventions to determine which is more effective for changing a behavior of interest. Sometimes an intervention has a solid research foundation, is recommended widely, and used frequently. Researchers may develop and study an innovation and want to compare it to the established intervention. The goal would be to determine whether the innovation or established intervention results in better outcomes. The variations may include parametric questions, such as whether using more or less of a procedure results in differential behavior changes. Sometimes research focuses on whether two or more interventions are more or less effective given a couple contextual variables. Contextual variables can be categorized on at least four dimensions: physical space and materials, social structure, temporal structure, and instructional characteristics.
