Many educational Randomized Controlled Trials (RCTs) collect baseline versions of outcome measures (pretests) to be used in the estimation of impacts at posttest. Although pretest measures are not necessary for unbiased impact estimates in well executed experimental studies, using them increases the precision of impact estimates and reduces sample…

This study, sponsored by the Institute of Education Sciences (IES) in the U.S. Department of Education, examines whether some early elementary school math curricula are more effective than others at improving student math achievement in disadvantaged schools. A small number of curricula, which are based on different approaches for developing…