The motivation for this paper is the authors' recent work on several randomized control trials in which they found the primary result, which averaged across subgroups or sites, to be moderated by demographic or site characteristics. They are led to examine a distinction that the Institute of Education Sciences (IES) makes between "confirmatory"…

Some form of a short interrupted time series (ITS) is often used to evaluate state and national programs. An ITS design with a single treatment group assumes that the pretest functional form can be validly estimated and extrapolated into the postintervention period where it provides a valid counterfactual. This assumption is problematic. Ambiguous…

This issue brief focuses on one particular report, released in September 2009, that has been widely cited by charter school advocates because it appears to show remarkable results. In the report, "How New York City's Charter Schools Affect Achievement," Stanford University professor Caroline Hoxby and her colleagues Sonali Murarka and…

An assessment framework is like a blueprint, laying out the basic design of the assessment by describing the mathematics content that should be tested and the types of assessment questions that should be included. It also describes how the various design factors should be balanced across the assessment. This is an assessment framework, not a…