Selecting a Control Group

Abstract

This study examines the randomization process in twelve different social reform projects in the fields of health, education, and law. All of the programs used the same type of evaluation plan: a true experimental design involving randomization of clients to treat ment and control conditions. The implementation of this plan is discussed for each project. In addition, the projects are analyzed in terms of five aspects of the assignment process. The relationships between these aspects and the successful or unsuccessful implementations of the twelve evaluation designs are discussed. Finally, recommenda tions are made about issues which should be considered by program administrators and researchers before planning and implementing a true experimental evaluation.