The Canadian Research Institute for Social Policy (CRISP) is pleased to announce that a new policy brief entitled “Value-Added Models in Education” by J. Douglas Willms is now available.
‘Value-added’ in education refers to the effects of schools and teachers on students’ learning outcomes. In practice, year-to-year gains in students’ test scores are compared to some standard, typically the average test score gains for a jurisdiction, after taking account in some way of students’ family background. ‘Value-added Models’ describe the learning process with a complex set of statistical procedures that attempt to isolate the effects on student outcomes attributable to schooling processes from those due to family influences and other factors outside of the school.
- Value-added is about the effects of tractable factors, such as the quality of instruction and classroom and school disciplinary climate. Most value-added models try to estimate it by specifying a model of learning and removing the effects of intractable factors, such as students’ ability when they enter school and family socioeconomic status (SES).
- League table comparisons that present average school test scores can be misleading if treated as a measure of value-added.
- The assessment of value-added needs to take account of students’ prior academic performance and their SES.
- The effects of school composition (e.g., school mean SES) on student learning cannot be easily separated from school context (i.e., the environment in which teaching and learning takes place). Therefore, comparisons of value-added that compare schools with markedly different mean SES can yield unfair comparisons.
- Using value-added models to assess teacher effects is problematic for several reasons. A viable approach requires a longitudinal design with repeated measures of learning outcomes over the course of a school year.
Click here to read the full policy brief: Value-Added Models in Education
Dr. J. Douglas Willms is Professor and Canada Research Chair in Human Development at University of New Brunswick and President of The Learning Bar Inc.