Abstract For decades, social scientists have been trying to answer causal questions about the effectiveness of certain programs or policies. The conventional methodology for answering such causal questions relies on the “no interference between different units” assumption; that is, a...

A number of recent studies have used surveys of neighborhood informants and direct observation of city streets to assess aspects of community life such as collective efficacy, the density of kin networks, and social disorder. The authors compare three estimators of a neighborhood social process:...

The National Institutes of Health sponsored a conference on the Design and Analysis Issues in Community Trials on March 23,1992, in Bethesda, MD. This article presents a synopsis of each of the seven presentations given at that conference and summarizes the discussion that followed.

Using data collected under the Trial State Assessment (TSA) of the National Assessment of Educational Progress (NAEP), this article describes and illustrates a two-stage statistical model for investigating state-to-state variation in mathematics achievement. At the first stage, within each...

Researchers commonly ask whether relationships between exogenous predictors, X, and outcomes, Y, are mediated by a third set of variables, Z. Simultaneous equations decompose the relationship between X and Y into an indirect component, operating through Z, and a direct component, the...

A number of recent studies have used surveys of neighborhood informants and direct observation of city streets to assess aspects of community life such as collective efficacy, the density of kin networks, and social disorder. The authors compare three estimators of a neighborhood social process:...

Fixed effects models are often useful in longitudinal studies when the goal is to assess the impact of teacher or school characteristics on student learning. In this article, I introduce an alternative procedure: adaptive centering with random effects. I show that this procedure can replicate...

The ability of school (or teacher) value-added models to provide unbiased estimates of school (or teacher) effects rests on a set of assumptions. In this article, we identify six assumptions that are required so that the estimands of such models are well defined and the models are able to...