By Leslie Booren
Researchers also found that the Washington, D.C. teacher evaluation program had positive effects on teacher quality.
Teacher turnover is often rightly perceived as a problem for schools. A growing body of evidence finds that teacher turnover reduces student achievement, either directly because replacement teachers are less effective than exiting teachers or indirectly through the disruptions caused by high turnover rates. This is especially true in schools whose students come from high-poverty households, where teacher turnover rates are especially high and where it is often very difficult to recruit effective new teachers who are as effective as those who left.
However, results from a new study shows that teacher turnover under IMPACT, the teacher-evaluation system used in the District of Columbia Public Schools (DCPS), improved student performance on average. The study also shows exiting teachers who were identified by IMPACT as low-performing, resulted in substantial improvement in overall teacher quality and student achievement.