Multisite trials, which are being used with increasing frequency in education and evaluation research, provide an exciting opportunity for learning about how the effects of interventions or programs are distributed across sites. In particular, these studies can produce rigorous estimates of a cross-site mean effect of program assignment…

The present article considers a fundamental question in evaluation research: "By how much do program effects vary across sites?" The article first presents a theoretical model of cross-site impact variation and a related estimation model with a random treatment coefficient and fixed site-specific intercepts. This approach eliminates…

This paper describes a place-based research demonstration program to promote and sustain employment among residents of selected public housing developments in U.S. cities. Because all eligible residents of the participating public housing developments were free to take part in the program, it was not possible to study its impacts in a classical…

Explores the possibility of randomly assigning groups (or clusters) of individuals to a program or control group to estimate the impact of programs designed to affect whole groups. Applies the cluster-assignment approach to the evaluation of education programs targeting whole schools. Discusses statistical implications of the method. (SLD)