Although program evaluations using rigorous quasi-experimental or experimental designs can inform decisions about whether to continue or terminate a given program, they often have limited ability to reveal the mechanisms by which complex interventions achieve their effects. To illuminate these mechanisms, this article analyzes novel text data from…

Most of the students who set out to earn degrees in community colleges never do. Interventions that simplify the complex organizational structures of these schools are promising solutions to this problem. This article is the first to provide rigorous evidence of the effects of structured transfer programs, one such intervention. Leveraging the…

This article examines the power analyses for the first wave of group-randomized trials funded by the Institute of Education Sciences. Specifically, it assesses the precision and technical accuracy of the studies. The authors identified the appropriate experimental design and estimated the minimum detectable standardized effect size (MDES) for each…

Demonstrating program impact through documentation of child progress is a problem in programs for handicapped children. It is proposed that intervenors consider approaches closely tied to the actual interventions. Four strategies are described: increased magnitude of intervention, increased power of design, refined assessment procedures, and…

The internal validity of the RMC models, especially Model A, is examined. Concern centers on limiting evaluation to cognitive outcomes, using constant percentile as the no-treatment expectation, and using norms for one test to establish the expected no-treatment performance level for another test. (MH)