Teacher turnover in Washington, D.C. Public Schools as a result of IMPACT, the District’s teacher evaluation system, has benefited students, according to a study published by the National Bureau of Economic Research on Jan. 25, amid lingering doubts about the system’s effectiveness.
IMPACT, implemented at the beginning of the 2009-10 school year, uses classroom observations, student growth measures and achievement indicators such as test scores to evaluate teachers. The system is considered high-stakes in that poor evaluations of “minimally effective” lead to termination and excellent ones of “highly effective” may result in bonuses and substantial pay increases.
Students whose teachers left after receiving poor evaluations from IMPACT performed better on math and reading tests taken after their teachers departed. From the school years between 2009 to 2012, the departure of teachers with negative IMPACT ratings led to rising levels of student achievement of up to 21 percent, which translated to more than four months’ worth of education in math and science.
University of Virginia Curry School of Education and Stanford University Graduate School of Education faculty members authored the report. Melinda Adnot, an author from the University of Virginia, explained that the study did not specifically evaluate IMPACT, but rather examined how the teacher turnover it created affected student achievement.
“Our study shows that teacher quality and student achievement in both math and reading increased substantially when low-performing teachers … exited DCPS,” Adnot wrote in an email to The Hoya. “When high-performing teachers leave the district it has an … effect [that] is small and statistically insignificant.”
Adnot noted that one of the factors that prompted the study was the high rate of teacher turnover in DCPS at 18 percent, compared to the average of 13 percent in urban school districts across seven states. The researchers will next investigate teachers’ behavioral responses to IMPACT and how they modify their curriculum as a result of the evaluations they receive.
“Teacher turnover generally has a negative impact on student achievement,” Adnot wrote. “We wanted to know how this relationship might be different in a district with a high-stakes evaluation system, such as IMPACT.”
However, negative opinions of IMPACT still persist, particularly in terms of its effects on high teacher turnover, a phenomenon generally viewed as disadvantageous for schools. President of the Washington Teachers’ Union Elizabeth Davis noted that in a 2012 study, 90 percent of D.C. teachers wanted to eliminate IMPACT. Davis cited the system’s subjective nature as well as its limited evaluation criteria as reasons to be skeptical of its value.
“No evidence has been provided to determine if IMPACT is working to retain effective teachers and get rid of ineffective ones,” Davis wrote in an email to The Hoya. “The Washington Teachers’ Union believes it is time to assess the success of these strategies and policies in regards to [IMPACT].”
Davis also alleged that IMPACT has not actually improved the quality of teaching in schools because of its lack of focus on working with individual teachers. According to Davis, school-based coaches charged with teacher training did not utilize IMPACT results in their program.
“[Evaluators] could not determine whether IMPACT has improved the actual quality of teaching and learning in the school system,” Davis wrote. “No attempt was made to get a subjective assessment of whether teachers feel they are benefitting from IMPACT.”
Chief of Human Capital for DCPS Jason Kamras, who designed the IMPACT system, said that he knew of WTU’s concerns and explained that DCPS has already made changes to the system. According to Kamras, most teachers who leave DCPS do not cite IMPACT as a reason for doing so.
“We’ve made changes in response to teacher feedback,” Kamras wrote in an email to The Hoya. “When we survey teachers who leave DCPS about the reason for their departure, IMPACT doesn’t even make it into the top 10.”
Davis also emphasized that IMPACT unfairly penalizes teachers who work in the poorest areas of D.C. She noted that the District has replaced over 3,300 teachers over the past eight years, many of whom left as a result of the lack of support they received in poverty-stricken areas of the city.
“The bad teacher narrative can no longer apply as a credible reason for the growing achievement gap in our school district,” Davis wrote. “The IMPACT evaluation system penalizes those teachers who take on the challenge of educating our neediest students.”
Kamras maintained his commitment to the system and expressed excitement over the results of the study, which he believes provide validation for IMPACT. Kamras said that DCPS will continue to use the system in the future.
“This is an incredibly exciting and important study. Four additional months of learning in reading and math is life-changing for students,” Kamras wrote. “IMPACT keeps the bar high in every part of the city, as it should.”
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