There is much interest in comparing latent traits, such as teacher job satisfaction, in large international surveys. However, different countries respond to questionnaires in different languages and interpret the questions through different cultural lenses, raising doubts about the psychometric equivalence of the measurements. Making valid…

This article examines how psychometric models based on certain assumptions have come to be used counterproductively by many practitioners in ways that limit the kinds of conclusions that can be made. The general problem of the context's influence on performance is discussed, and some implications are drawn. (SLD)

This instructional module discusses the one-, two-, and three-parameter logistic item response theory (IRT) models. Mathematical formulas are given for each model and they are compared, with figures illustrating the effects of changing parameters. A single data set is used to demonstrate the effects of changing parameter values. (SLD)

The author describes the evolution of the Scholastic Aptitude Test (SAT). He describes some of the contributions to educational research made by inquiries based on the SAT and gives particular attention to the way scaling and equating procedures for the SAT have evolved over the last half century. (Author/JAZ)