Teachers in the District of Columbia Public Schools (DCPS) improved because of the school system’s teacher evaluation system (IMPACT), according to a new study out today. The study, released by the Stanford Graduate School of Education and the University of Virginia Curry School of Education, also found DCPS is replacing low-performing teachers with even stronger teachers, and the school system is retaining its best teachers at very high rates.
“Every DCPS parent – myself included – wants a great teacher for their children. It’s why we’ve staked our reputation on building the strongest teaching force in the country,” said DCPS Chancellor Kaya Henderson, a key architect of the IMPACT evaluation system. “It’s why we’ve focused so much of our energy on making sure that every classroom in every ward has a teacher that inspires their students to achieve at the highest levels. We still have so much work to do, but as this study shows us, we’re making enormous progress towards this goal.”
IMPACT, now in its fifth year, is a cornerstone of DCPS’s efforts to create a world-class school system. Based on a variety of factors, including how much a teacher’s students learn over the course of the year as well as classroom observations by principals and expert teachers, educators receive one of five ratings under IMPACT: Highly Effective, Effective, Developing, Minimally Effective, or Ineffective. As part of the system, teachers receive written feedback, coaching, and other supports to help them improve their practice. Teachers scoring Highly Effective are eligible for bonuses up to $25,000 per year as well as increases in their annual base salary.
The study released today, Incentives, Selection, and Teacher Performance: Evidence from IMPACT, by James Wyckoff, professor of education at the University of Virginia Curry School of Education and Thomas Dee, professor of education at the Stanford Graduate School of Education, has three key findings: 1) IMPACT is responsible for substantial improvements in teacher practice; 2) DCPS is retaining its best teachers at very high rates; and 3) IMPACT causes some low-performing teachers to leave the school system on their own – and, more importantly, DCPS is replacing those educators with higher caliber ones.
Better Teaching
The study’s authors find strong evidence that IMPACT’s incentives led to meaningful improvements in teacher practice for both low-performing teachers and high-performing ones. At the low end, for example, the study finds that because of IMPACT, teachers rated Minimally Effective improved an average of 12.6 points on the 100-400 IMPACT scale in one year. That’s more than half the amount that new teachers typically improve over their firstthree years. At the high end, the study finds that Highly Effective teachers also improved because of IMPACT, by an average of 10.9 points.
“We built IMPACT to increase accountability in DCPS and provide support to our educators,” said Henderson. “While there’s certainly more work to do, this study shows that IMPACT is achieving both of these important goals. I am very encouraged to see the positive effects it is having on teacher practice."
Better Retention
Following the 2010-11 and 2011-12 school years, DCPS retained 92 percent of its best teachers (those who earned Highly Effective ratings) on average. During the same period however, only 59 percent of Minimally Effective teachers were retained on average.
“Great teachers – those who nurture children to reach beyond their wildest dreams – are what every student deserves," said Jason Kamras, Chief of the Office of Human Capital. “We want to make sure that we’re doing everything we possibly can to keep them in DCPS. We know we have more to do on this front, but are gratified to see from this study that such a high percentage are choosing to stay.”
Better Hiring
The study finds that IMPACT motivated many low-performing teachers to leave DCPS voluntarily. For example, more than 30 percent of first-time Minimally Effective teachers left voluntarily, while only thirteen percent of Effective or Highly Effective teachers did so.
More importantly, though, the study finds that DCPS was able to recruit better teachers to replace those who chose to leave. For example, teachers who left DCPS at the end of the 2010-2011 school year had an average IMPACT score of 255 (on the 100-400 scale), while those who entered the following year had an average score of 281, a substantial 26-point difference.
More information about the study is available here.
More information about IMPACT is available on the DCPS website here.
DCPS presentation with details available here.
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