Overview of Value-Added Research in Education: Reliability, Validity, Efficacy, and Usefulness. Value-added modeling (VAM) is a statistical approach that provides quantitative performance measures for monitoring and evaluating schools and other aspects of the education system. VAM comprises a collection of complex statistical techniques that use standardized test scores to estimate the effects of individual schools or teachers on student performance. Although the VAM approach holds promise, serious technical issues have been raised regarding VAM as a high-stakes instrument in accountability initiatives. The key question remains: Can VAM scores of standardized test scores serve as a proxy for measuring teaching quality? To date, research on the efficacy of VAM is mixed. There is a body of research that supports VAM, but there is also a body of studies suggesting that model estimates are unstable over time and subject to bias and imprecision. A second issue with VAM is the sole use of standardized tests as a measure of student performance. Despite these valid concerns, VAM has been shown to be valuable in performance improvement efforts when used cautiously in combination with other measures of student performance such as end-of-course tests, final grades, and structured classroom observations.
Citation: Cleaver, S., Detrich, R. & States, J. (2020). Overview of Value-Added Research in Education: Reliability, Validity, Efficacy, and Usefulness. Oakland, CA: The Wing Institute. https://www.winginstitute.org/staff-value-added.