Evaluators of education interventions are increasingly designing studies to detect impacts much smaller than the 0.20 standard deviations that Cohen characterized as "small." While the need to detect smaller impacts is based on compelling arguments that such impacts are substantively meaningful, the drive to detect smaller impacts may…

This article discusses the circumstances under which unequal sample size in the two-group study can arise and result in an attenuated point-biserial correlation. Formulas are provided for correcting the coefficient either directly or through the mediation of relevant statistics found in studies where the coefficient itself is not reported.…

Methods of using simplified time series analysis (STSA) in evaluating clinical programs are discussed. STSA assists in addressing problems of attrition/augmentation of subjects in programs with changing populations. Combining individually calculated "C" statistics in a simple aggregate analysis of restraint usage by nursing home staff…