Single case research design plays a pivotal role in the identification and description of evidence-based interventions with persons with intellectual and developmental disabilities. Since the methodology was first described over 50 years ago, thousands of published studies using single case research designs have demonstrated the efficacy of a wide range of individualized interventions.

Single case research designs are used to determine the degree to which an independent variable (intervention) is responsible for changes in a dependent variable (target behavior). Single case research designs have utility as both research tools and methods for clinical evaluation. For example, single case research designs may be used when conducting a functional behavioral assessment (FBA) of interfering behaviors or as a way to empirically evaluate the effectiveness of an intervention with ...