Henry I. Braun, Educational Testing Service
Anthony D. Lutkus, Educational Testing Service
Abstract: Value-added statistical models (VAMs) require data that track individual students' academic growth over several years and different subjects in order to estimate the contributions that teachers make to that growth. Despite enthusiasm for these models, several technical reviews have revealed a number of serious concerns. Implementation of VAMs and the proposed uses of results raise a host of practical, technical, and even philosophical issues. This session will serve as a layman's guide to these issues, aiding deliberations on the appropriate uses of this powerful statistical tool. Topics covered include: the nature of causal interpretation, random assignment of students to classrooms, school characteristics, the nature of test scores, identifying teachers for professional development.