Randomized experiments involving education interventions are typically implemented as cluster randomized trials, with schools serving as clusters. To design such a study, it is critical to understand the degree to which learning outcomes vary between versus within clusters (schools), specifically the intraclass correlation coefficient. It is also…

A method is presented that allows multivariate comparability while making only minimal restrictions on randomization. This procedure is demonstrated in the context of assigning 63 aggregated units (schools) to 28 experimental and control conditions. Good comparability of groups for all primary main effects and interactions was verified for 15…

In an overview of single-case methodology, the potential utility of A-B-A and multiple baseline designs for evaluating social programs is discussed. Validity factors and cost-effectiveness are considered, showing that these designs are viable alternative methods where traditional randomized group designs are infeasible. (Author/CM)

A method is presented for analyzing data collected in a multiple group time-series design. This consists of testing linear hypotheses about the experimental and control group-means. Both a multivariate and a univariate procedure are described. (Author/GK)