The study examined differences in student achievement when students were taught by a teacher with high or low value-added, a measure of teacher effectiveness. The study sample included about 3,300 cohorts of math and reading students in grades 4-8 in a large, urban school district. This What Works Clearinghouse (WWC) review focuses on the report’s analyses of what happened to students’ achievement as a result of the movements of teachers with relatively high or low value-added estimates.
Study authors reported that when a high value-added teacher started to teach students in a cohort or a low value-added teacher stopped teaching students in a cohort, the event was associated with a statistically significant increase in reading and math test scores.
In addition, when a high value-added teacher stopped teaching students in a cohort or a low value-added teacher started teaching students in a cohort, the event was associated with a statistically significant decrease in test scores.
Chetty, R., Friedman, J. N., & Rockoff, J. E. (2011). The long-term impacts of teachers: Teacher value-added and student outcomes in adulthood (NBER Working Paper 17699). Cambridge, MA: National Bureau of Economic Research.