Beyond measuring average program impacts, it is important to understand how impacts vary. This paper gives a broad overview of the conceptual and statistical issues involved in using multisite randomized trials to learn about and from variation in program effects across individuals, across subgroups of individuals, and across program sites.
New Directions in Evaluations of American Welfare-to-Work and Employment Initiatives
Methodological Lessons from an Evaluation of Accelerated Schools
The Effects of Program Management and Services, Economic Environment, and Client Characteristics