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Measuring Teacher Performance More Meaningfully

For most of public education's history, teacher evaluation was an after-thought. Despite the centrality of teachers to the education enterprise and the fact that taxpayers spend a fortune on public school teacher compensation and benefits (today, upwards of half a trillion dollars), the standard evaluation model was a quick classroom check-in once a year by a principal looking for clean classrooms and quiet kids—things that didn't directly capture the quality of teaching, much less student learning.

Because public school teachers have traditionally been hired, paid, and promoted strictly on the basis of their college credentials and their years in the classroom, there were few incentives for school systems to thoughtfully compare teacher performances. And most school systems didn't.

That changed when the Obama administration gave state and local policymakers substantial financial and regulatory incentives to take evaluation more seriously. Nearly every state in the country toughened scrutiny of public school teacher performance between 2009 and 2015.

But the 2016 Every Student Succeeds Act eliminated the Obama incentives under pressure from teacher unions that didn't like the new scrutiny of their members and anti-Washington Tea Party members and their conservative congressional allies. And new Secretary of Education Betsy DeVos hasn't shown any inclination to support the reforms.

[Read More: Grading the Graders]

That's too bad. The evaluation reforms, while still evolving, have already produced important improvements in the nation's schools.

The new measurement systems are typically more comprehensive, are built on clearer teaching standards than traditionally existed in public education, and, when done responsibly, are truer measures of teacher performance than their check-list predecessors.

Researchers Matthew Kraft of Brown University and Allison Gilmour of Vanderbilt reported recently that the evaluation reforms have produced “a meaningful increase” in the identification of under-performing teachers. While Kraft and Gilmour study of 19 new evaluation systems found that a median of 2.7 percent of teachers were rated unsatisfactory, some school districts have started to remove ineffective teachers from classrooms, a rare occurrence in public education in the past.

In the District of Columbia, where classroom observation scores are combined with student-achievement results and other measures, only 80 percent of the city’s teachers were rated effective or highly effective last year. Another 17 percent were placed on two levels of probation. And 3 percent were fired.

And even in states and school districts with high percentages of satisfactory ratings, new evaluation systems have paid dividends.

The new systems have forced principals to prioritize classrooms over cafeterias and custodians (and have exposed how poorly prepared many principals are to be instructional leaders), sparking conversations in schools about effective teaching that often simply didn’t happen in the past—developments that teachers say makes their work more appealing.

[Read More: Exploring The Human Side of Teacher Evaluation]

New information flowing from the upgraded measurement systems’ designs is helping education leaders make smarter staffing decisions. In addition to helping remove underperforming teachers, the best of the new evaluation systems are supplying the foundation for new, performance-based pay systems and career ladders that lets top teachers earn substantially higher salaries and take on new roles like team leaders, mentors, and peer coaches, helping to keep top talent in schools.

The District of Columbia system has used the results from its new evaluation system to measure the effectiveness of a new teacher hiring model; the district found that teachers who scored high on its new recruitment tool when on to earn higher evaluation scores once they get into classrooms. Similarly, the city can now target its teacher recruitment efforts on training programs that DCPS statisticians have shown to produce top performers.

While the use of student test scores in teacher ratings and the reform movement’s early focus on removing bad apples turned many teachers against the new evaluation systems, these emerging professional opportunities and the linking of evaluation results to improved resources are changing many teachers’ minds.

And there’s emerging evidence that the strategies are improving public education's bottom line. The researchers Thomas Dee of Stanford and James Wyckoff of the University of Virginia have reported that the departure of low-rated teachers under the District of Columbia’s new evaluation system, combined with a push to recruit strong replacements, “substantially improves teaching quality and student achievement in [Washington’s] high-poverty schools.” They found that students with replacement teachers learned the equivalent of between a third and two-thirds of a year of additional study in math, and nearly as much in reading.

There’s certainly plenty of work to do to improve the quality of the new evaluation systems, improvements that are likely to bring the differences in teacher performance into sharper focus.

But it’s also increasingly clear that the new generation of teacher evaluations have the potential to strengthen instruction, make teaching more attractive work, and raise student achievement on a wide scale—if states and school districts stay the course on reform.