How to Study the Influence of Intensity of Treatment on Generalized Skill and Knowledge Acquisition in Students with Disabilities.

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 expense of treatment. Second, we encourage researchers to define dependent variables in a way that allows us to determine whether treatment intensity effects on child skills and knowledge are highly generalized versus potentially context bound. Third, we acknowledge that effects of treatment intensity on generalized knowledge and skills likely vary according to student characteristics. Finally, we discuss important research design and measurement issues that are relevant to isolating the likely conditional effects of treatment intensity on generalized outcomes.