To: State Legislators and Policy Makers From: Eric Lerum - Vice President of National Policy, StudentsFirst RE: Groundbreaking New Study Highlights Importance of Implementing Meaningful Teacher Evaluations With many state legislatures back in session this month, leaders all around the country are considering how we can ensure that our students all have great teachers in their classrooms. A groundbreaking new study released last week by researchers from Harvard and Columbia provides important new information for guiding how we think about building and implementing meaningful teacher evaluation models. As you and your colleagues consider such policies, we thought it might be valuable to summarize and share some of the study’s key findings to help better guide your policymaking efforts. The study contains two key implications for policy questions surrounding evaluations. First, effective teachers (as identified by value-added assessments based on student growth on tests, adjusted for demographic factors) are highly correlated with positive impacts outside the classroom. This means that the work of an effective teacher ultimately does much more than just raise a student’s test scores (though it does that too). Second, these value-added models are able to differentiate and identify effective teachers clearly and with significant accuracy. These findings are particularly notable because they address key concerns about the use of value-added measures based on student achievement growth in teacher evaluations and personnel decisions. The study, which was conducted over 20 years, indicates that what we can estimate in terms of a teacher’s impact on student achievement is also highly predictive of the impact the teacher will have on a student’s life trajectory. The Study: “The Long-Term Impacts of Teachers: Teacher Value-Added and Student Outcomes In Adulthood.”1 This report is groundbreaking in terms of the scale of the data that is collected and the quality of results which we are able to infer from it. The report analyzed school district data for grades 3 through 8 for 2.5 million children over 20 years, and linked that data to tax records to identify parent characteristics and adult outcomes. Because of the unprecedented scope in time-series and sample size, the study is able to address one frequent criticism of value-added testing, that it often produces great variance in scores as a teacher moves from class to class. Critics particularly point to the high margin of error with many value-added ratings. But in looking at individual teachers’ value-added scores, the researchers found that some consistently outperformed their peers. The Findings: Better Student Outcomes With Better Teachers The study found that students who had teachers that were identified as effective (by their value-added scores, based on student test performance and growth) were more likely to attend college, attend higher-ranked colleges, earn higher salaries, and live in better neighborhoods, and had lower rates of teen pregnancy. These teachers were clearly linked to better life outcomes and strong success in the student’s future educational and career endeavors. For instance, the report found that even marginal improvements to the quality of a student’s teacher were directly linked to a measureable increase in earnings later in life (the report estimates that a statistical improvement of one standard deviation in a teacher’s rated effectiveness increases earning by about 1% by the time the student reaches age 28). Startlingly, the report also found that replacing a teacher whose effectiveness was rated in the bottom 5% with an average teacher would increase lifetime earnings for the average classroom by more than $250,000. The

1 Chetty, J., Friedman, J.N., & Rockoff, J.E. (2011). The Long-Term Impacts of Teachers: Teacher Value-Added and Student Outcomes in Adulthood (Working Paper No. 17699). Retrieved from National Bureau of Economic Research website: http://papers.nber.org/papers/w17699

reports authors write, “We conclude that good teachers create substantial economic value and that test score impacts are helpful in identifying good teachers.” Students Learn More From Good Teachers Among the theories the report’s authors set out to test was the question of whether teachers whose students score well on tests genuinely improve student outcomes, or are simply better at teaching to the test. In addition to finding that effective teachers produced a variety of positive life outcomes and drove student success, they also found that the gains from effective teachers stayed with students well into the student’s future. While gains from the initial year do fade out over time, the report indicates that they stabilize at about 1/3rd of the original impact after three years, showing that a solid amount of the achievement gains persist. The charts below (taken from a presentation compiled by the study’s authors2) show the lagged impact, as well as a clearly correlated increase in college attendance rates for students with highly rated teachers, just one example of the improved educational outcomes that highly rated teachers impart.

These Models Effectively Differentiate, Identifying Teachers Who Are Great, and Those Who Aren’t The study finds that a teacher’s value-added scores are clearly predictive of the success they have in teaching students, and therefore the success the students themselves will achieve, in their scores on assessments and in other indicators outside of and after they complete school. As the study’s authors write, “the findings in this paper and prior work are sufficient to conclude that standard estimates of teacher [value-added] can provide accurate forecasts of teacher’s average impacts on student’s test scores.” They also note that “good teachers create substantial economic value and that test score impacts are helpful in identifying such teachers.” Thanks to the scope of the study, the potential for variance due to differences among the students in different classrooms that some critics point to appears to be minimal. As the New York Times puts it, "the researchers found that some [teachers] consistently outperformed their peers," regardless of the classroom they were leading. The charts below (also taken from the study presentation) illustrate this value clearly. The first shows the effect of entry of a high value-added teacher on their students’ performance, with clear gains being demonstrated immediately. The second shows the harmful effects of entry of a low value-added teacher, also realized immediately. In both cases, this evidence of change in student learning outcomes – whether they improve or decline – is stark, and closely tied to the effectiveness of the teacher. 2 http://obs.rc.fas.harvard.edu/chetty/value_added.html

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College Attendance at Age 20 vs. Teacher Value-Added

Conclusion This groundbreaking study confirms and lends even greater credibility to what previous research has shown us - quality teaching is the key factor in student outcomes; students learn more from high performing teachers; and value-added models effectively identify high performing teachers and those who need additional development. In short, it confirms what anyone who has ever had a great teacher knows already – great teachers matter. They have a huge impact, and that impact lasts well beyond the classroom. If you have any questions about the study, please contact our policy office and we would be happy to assist you. You can contact me directly at Eric@StudentsFirst.org.

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Score = 0.036 TVA = 0.038

p [score = 0] < 0.001 p [score = TVA] =0.79 Number of Events = 1663

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Impact of Low Value-Added Teacher Entry on Cohort Test Scores

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Score = -0.019 TVA = -0.030

p [score = 0] < 0.001 p [score = TVA] =0.07