Longitudinal studies can produce biased estimates of learning if children miss tests. In an application to summer learning, we illustrate how missing test scores can create an illusion of large summer learning gaps when true gaps are close to zero. We demonstrate two methods that reduce bias by exploiting the correlations between missing and…

Clustered observational studies (COSs) are a critical analytic tool for educational effectiveness research. We present a design framework for the development and critique of COSs. The framework is built on the counterfactual model for causal inference and promotes the concept of designing COSs that emulate the targeted randomized trial that would…

The evidence that student learning declines sharply (or stagnates) during the summer has motivated a substantial interest in programs that provide intensive academic instruction during the summer. However, the existing literature suggests that such programs, which typically focus on just one or two subjects, have modest effects on students'…