Recruitment is a key challenge for researchers conducting any large school-based study. Control is needed not only over the condition participants receive, but also over how the intervention is implemented, and may include restrictions in other areas of school and classroom functioning. We report here on our experiences in recruiting participants…

In this set of four supplemental tables, the authors compare the baseline test scores of the treatment and matched control group samples observed in each year after KIPP entry (outcome years 1 to 4). As discussed in Chapter III, the authors used an iterative propensity score estimation procedure to calculate each student's probability of entering…