The Obama administration has worked hard to strengthen public-school teaching—a $400 billion-plus workforce, and perhaps the single strongest lever in schools for raising student achievement. But just after Thanksgiving, the president signed a major new education law that largely abandoned the cornerstone of his teacher agenda: pressing states and school districts to take more seriously the task of identifying who in the profession was doing a good job, and who wasn't.

Two powerful forces at opposite ends of the political spectrum had attacked the president’s strategy—teacher unions wanting to end the new scrutiny of their members and Tea Party members targeting the Obama plan as part of a larger anti-Washington campaign. As a result, the new Every Student Succeeds Act terminates the Obama administration’s incentives for states and school districts to introduce tougher teacher-evaluation systems. And the law effectively bans the U.S. Secretary of Education from promoting teacher-performance measurements in the future.

The teacher unions have dismissed the Obama strategy as ineffective, as more hurtful than helpful to the teaching profession. But over three dozen states have embraced more meaningful teacher-measurement systems under the Obama incentives, combining features like clearer performance standards, multiple classroom observations, student-achievement results and, increasingly, student surveys. And state and local studies, teacher surveys, and other evidence reveals that many of the new systems have been much more beneficial than the union narrative would suggest.

Before the Obama administration stepped in, the standard evaluation for the nation’s 3 million teachers was a cursory classroom check-in once a year by principals focused on quiet students and clean whiteboards—exercises that didn't focus directly on the quality of instruction, much less student learning.

Now, the picture is more promising. A growing body of research and dozens of interviews with policymakers, experts, and others suggest that the new, more comprehensive evaluation systems have strengthened many school districts’ focus on instructional quality. They’ve forced principals to prioritize classrooms over bus schedules and lunch menus and sparked conversations in school buildings about effective teaching that often simply didn’t happen in the past.

New information flowing from the improved evaluation designs seems to be helping education leaders make smarter staffing decisions. Prior to the Obama push, there wasn’t a single state that required school districts to weigh teaching performance—and not just years of service—in granting teacher tenure and the substantial job protections it provides. Now, with more dependable ratings in place, nearly two dozen states do so, the National Council on Teacher Quality reports. The District of Columbia’s school system uses the results from its new evaluation system to identify teacher-training institutions that produce the city’s highest-rated teachers and is prioritizing those providers in its recruitment of new teachers.

And school districts increasingly are going beyond identifying leaders and laggards, using evaluation results to help teachers improve their performance. In one example, the Brown University researchers John Tyler and John Papay have partnered with the Tennessee Department of Education to craft a program that matches teachers who do well on components of the state’s new teacher-evaluation systems with colleagues who struggle. In an experiment, teachers in schools where the peer partnerships were introduced were more supportive of tougher teacher evaluations than in schools that didn’t get the program, and the partnership schools turned in higher student test scores in subsequent years.

New digital companies like BloomBoard and TeachBoost have begun drawing on the results of the new evaluation systems to provide teachers with personalized “playlists” of model lessons, readings, and other improvement materials based on their evaluation results. In the past, public education has spent billions of dollars annually trying to improve teachers through what has been mostly a patchwork of widely disparaged workshops frequently having little to do with teachers’ individual needs.

The best of the new evaluation systems are supplying a foundation for a wide range of new, performance-based teacher roles that are making teaching more attractive. Hillsborough County, Florida, and New Haven, Connecticut, are among the school districts where highly rated teachers now serve as peer evaluators or lead teachers. 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 reforms are improving public education's bottom line. In addition to the Tennessee results, the researchers Thomas Dee of Stanford and James Wyckoff of the University of Virginia recently 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.

The evaluation reforms have been far from perfect. In my research I found that experts struggled to craft dependable new measurement models on tight timelines, especially in building student achievement into the new ratings—resulting in non-sensical situations like gym teachers being evaluated by fourth-grade reading scores. High percentages of teachers have continued to get top ratings in school districts that rely too heavily on under-trained principals who don’t want to create waves in their schools. Many school districts have struggled with the price tag of additional teacher evaluations, as a new report on teacher evaluation from the think tank New America notes. Evaluations aren’t producing enough improvement opportunities for teachers in many places. And there’s no doubt that former Education Secretary Arne Duncan’s decision to have states stress student test scores in new teacher evaluation systems—while also having them introduce new, more demanding tests linked to the important-but-controversial Common Core State Standards—made an already challenging task vastly more difficult and handed teacher unions an easy way to attack the Obama reforms.

But it’s clear from the many new evaluation initiatives launched in recent years that well-designed evaluation systems with a mix of measures, multiple evaluators, and a strong focus on teacher improvement can strengthen instruction, make teaching more attractive work, and raise student achievement.

The question is whether state and local education leaders will stay the course on teacher-evaluation reform, now that the Obama incentives have been eliminated under ESSA. They’ll surely face strong union pressure to return to the superficial evaluation systems of the past. But the hard-learned lessons of the past several years suggest that building on the strengths of the Obama-era reforms and addressing their weaknesses would benefit both students and teachers.