This paper describes the parallel treatments design, a nested single subject experimental design that combines two concurrently implemented multiple probe designs, allows control for effects of extraneous variables through counterbalancing, and replicates its effects across behaviors. Procedural guidelines for the design's use and issues related…

A review of 20 research studies on the use of constant time delay in teaching chained tasks is analyzed in regard to demographic variables (participants, settings), procedural variables (probe format, delay sessions), outcome measures (effectiveness, generalization), and methodological adequacy (dependent and independent variable reliability). (DB)