In the wake of high-profile evaluations of teachers using their students鈥� test scores, such as , a released last month suggests some such methods, called 鈥渧alue added鈥� measures, are too imprecise to rate teachers鈥� effectiveness.
Among the problems, conclude researchers from the , at Brown University, is that schools do not use a single, vertically aligned test for each subject, which is needed to track growth, and tests do not cover all state standards proportionately. The authors argue that value-added measures are most accurate for teachers with many years of student data, and less useful for novice teachers, who are more likely to need feedback.
