It is often difficult and costly to obtain individual-level student achievement data, yet, researchers are frequently reluctant to use school-level achievement data that are widely available from state websites. We argue that public-use aggregate school-level achievement data are, in fact, sufficient to address a wide range of evaluation questions…

We use data from a randomized controlled trial of a middle school science intervention to explore the causal mechanisms by which the intervention produced previously documented gains in student achievement. Our study finds that implementation fidelity, operationalized as a measure of the frequency of implementation of the cognitive science…

This article examines how controlling statistically for baseline covariates, especially pretests, improves the precision of studies that randomize schools to measure the impacts of educational interventions on student achievement. Empirical findings from five urban school districts indicate that (1) pretests can reduce the number of randomized…

A meta analysis of preschool intervention programs is performed to arrive at an overall effect size of such programs. Results indicate that despite the diversities in intervention sites, ages of subjects, lengths of intervention, and curricula models, there is a positive homogeneous effect on the variables. (Author/LMO)

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)

Major changes in Massachusetts public policy governing early intervention programs for very young disabled children were described. The process of policy change and formation was analyzed by focusing on the principal catalysts for change. Factors were examined in terms of issue definition, proposal formulation, support mobilization, and decision…