Study: DC IMPACT Teacher Evaluation System Improves Performance

A new study by researchers at the University of Virginia’s Curry School of Education and the Stanford Graduate School of Education found that a controversial teacher evaluation system introduced in the District of Columbia Public Schools has been a success.

The teacher evaluation system, called IMPACT, is a performance assessment system linking high-powered incentives and teacher evaluations. According to the study, the system has improved the performance of hundreds of teachers in the district and also encouraged some low-performing teachers to voluntarily leave the district’s classrooms.

High-performing teachers earn an annual bonus of as much as $25,000 as well as an opportunity for similarly large and permanent increases in their base salaries. Teachers who are unable to achieve an “effective” rating after two years are dismissed.

“IMPACT provides a unique opportunity to examine the effects of a multi-faceted system of teacher evaluation and supports, coupled with non-trivial incentives for teacher performance. We find strong evidence that this system causes meaningful increases in teacher performance,” said James Wyckoff, professor of education at the Curry School and co-author of the study.

The study will be posted as a National Bureau of Economic Research working paper.

“We know that good teachers make a dramatic difference in the lives of their students,” said Thomas Dee, professor of education at Stanford and co-author of the study. “However, we also know that there is considerable variation in teacher quality. and too many disadvantaged children don’t have access to the highly effective teachers they need to realize their potential.”

The D.C. public schools implemented IMPACT during the tenure of Chancellor Michelle Rhee. The district first began evaluating teachers during the 2009-10 school year and the program’s teacher performance assessments are based on multiple measures of performance, not just students’ test results.

School administrators observe teachers in their classrooms five times throughout the year and rate on nine explicit criteria that the district uses to define effective instruction, including how well they explain concepts and if they check for student understanding. Also, teachers are rated on their support of school initiatives, their efforts to promote high expectations and their demonstration of core professionalism.

Teachers are rated on a scale of 100 to 400, and  a score of 350 or more means highly effective; 250 or more means effective; under 250 means minimally effective and under 175 means ineffective.

Teachers scoring above 350 receive a bonus for a given year, and a permanent pay increase if they exceed the bar for a second consecutive year. Effective teachers receive their scheduled pay increases, while ineffective teachers are immediately dismissed. The minimally effective teachers are given one year to become effective or they face the threat of dismissal.