Researchers have become increasingly interested in programs' main and interaction effects of two variables (A and B, e.g., two treatment variables or one treatment variable and one moderator) on outcomes. A challenge for estimating main and interaction effects is to eliminate selection bias across A-by-B groups. I introduce Rubin's causal model to…

There is often confusion about distinctions between growth models and value-added models. The first half of this paper attempts to dispel some of these confusions by clarifying terminology and illustrating by example how the results from a large-scale assessment can and will be used to make inferences about student growth and the value-added…

As part of No Child Left Behind (NCLB) legislation, many states are using confidence intervals to determine a range of scores for evaluating a school system. More specifically, the states are employing confidence intervals to help minimize measurement error in determining a school system's performance. The methodology and techniques employed in…

A comprehensive assessment of the literacy proficiencies of Job Training Partnership Act (JTPA) and Employment Service/Unemployment Insurance (ES/UI) participants was conducted by the Department of Labor. The survey responses of a sample of 2,501 JTPA applicants and 3,277 ES/UI participants were scored, weighted, analyzed, and used to develop a…