Generalized single-case randomization tests: Flexible analyses for a variety of situations

A general class of single-case statistical procedures, derived from previou sly developed nonparametric randomization tests, is presented. These proced ures are widely applicable in behavioral and educational research contexts in which only a few experimental "units" (individuals, small groups, or cla ssrooms) are the recipients of one or more experimental treatments or inter ventions. Specifically illustrated are designs that focus on both the gener al and comparative effectiveness of alternative interventions (including co ntrol/placebo treatments), multiple units with differentiable characteristi cs (i.e., intervention by unit characteristic interactions), and multiple o utcome measures (i.e., intervention by outcome measure interactions). Also provided are operational modifications that enhance the internal validity o f studies incorporating single-case randomization-based analyses. Appropria te cautions and issues surrounding the use of these procedures are included .