Measuring Teacher Effectiveness
A Resource for Teachers, Administrators, Policymakers, and Parents
Many personal, family, and neighborhood factors contribute to a student's academic performance, but a large body of research suggests that, among school-related factors, teachers matter most. What's less clear, however, is how to measure an individual teacher's effectiveness.
It's a complex topic, and there are many factors that should be considered. RAND Education has applied its expertise to this and nearly every other aspect of the education system for more than three decades. This site is for teachers, administrators, policymakers, parents, and anyone else seeking objective, nonpartisan information on measuring teaching effectiveness.
Research suggests that, among school-related factors, teachers matter most when it comes to a student's academic performance. Nonschool factors do influence student achievement, but effective teaching has the potential to help level the playing field.
Teaching is a complex activity that should be measured with multiple methods. Some examine teachers' practices directly, while others emphasize student outcomes. Each method has trade-offs, and no single method provides a complete picture of a teacher's effectiveness.
Students' scores on achievement tests tell us something—but by no means everything—about how well teachers are meeting expectations.
Value-added models, or VAMs, attempt to measure a teacher's impact on student achievement apart from other factors, such as individual ability, family environment, past schooling, and the influence of peers.
Student growth percentiles, or SGPs, provide a simple way of comparing the improvement of one teacher's students at the end of the year with the improvement of other students who started the year at the same level.
As schools and districts move toward performance-based teacher evaluation as a way to improve teaching effectiveness and student outcomes, the principal's role in teacher evaluations is becoming even more important.