In a traditional regression-discontinuity design (RDD), units are assigned to treatment on the basis of a cutoff score and a continuous assignment variable. The treatment effect is measured at a single cutoff location along the assignment variable. This article introduces the multivariate...

Since 1980, the number of state pre-kindergarten (pre-K) programs has more than doubled, with 38 states enrolling more than one million children in 2006 alone. This study evaluates how five state pre-K programs affected children's receptive vocabulary, math, and print awareness skills. Taking...

This paper reviews the literature on whether regression-discontinuity studies reproduce the results of randomized experiments conducted on the same topic. After briefly reviewing the regression-discontinuity design and its history, we explicate the general conditions necessary for a strong test...

Propensity score analysis is a relatively recent statistical innovation that is useful in the analysis of data from quasi-experiments. The goal of propensity score analysis is to balance two non-equivalent groups on observed covariates to get more accurate estimates of the effects of a treatment...

This study describes a method for incorporating external estimates of intraclass correlation to improve the precision for the analysis of an existing group-randomized trial. The authors use a random-effects meta-analytic approach to pool the information across studies, which takes into account...