Randomized Controlled Trials for Evaluation and Planning

This chapter covers basic definitions and aims of randomized trials and the distinction between this approach and others that purport to estimate effects of interventions. Illustrations are considered next, partly to show how trials are mounted in different arenas, partly to provide evidence against naive academic, institutional, and political claims that such trials are not feasible. We next consider basic ingredients of a randomized trial; each ingredient is handled briefly. The final section summarizes efforts to develop capacity. This chapter updates one that appeared in the earlier edition of Bickman and Rog (1998); the update is no easy task given the remarkable expansion in trials over the past decade in education, crime and justice, social services, and other areas.