Determining how best to meet the needs of learners with Down syndrome requires an approach to intervention delivered at some level of intensity. How treatment intensity affects learner acquisition, maintenance, and generalization of skills can help optimize the efficiency and cost-effectiveness of interventions. There is a growing body of research…

Seven empirical studies from this special issue and an overview chapter are reviewed to illustrate several points about studying the possible effects of treatment intensity manipulations on generalized skill or knowledge acquisition in students with disabilities. First, we make a case in favor of studying intensity as separate from complexity and…

Basic and applied research related to the effects of interspersing trials of maintenance (i.e., review) tasks among trials of acquisition tasks on academic skill development is reviewed. In general, empirical research suggests that interspersing procedures are effective in facilitating acquisition, learning rate, and maintenance. However, some…