It is often assumed that a vertical scale is necessary when value-added models depend upon the gain scores of students across two or more points in time. This article examines the conditions under which the scale transformations associated with the vertical scaling process would be expected to have a significant impact on normative interpretations…

In this article, a new method is presented and implemented for deriving a scale of socioeconomic status (SES) from international survey data using a multilevel Bayesian item response theory (IRT) model. The proposed model incorporates both international anchor items and nation-specific items and is able to (a) produce student family SES scores…

Longitudinal, student performance-based, value-added accountability models have become popular of late and continue to enjoy increasing popularity. Such models require student data to be vertically scaled across wide grade and developmental ranges so that the value added to student growth/achievement by teachers, schools, and districts may be…