It's common to hear that teachers should be paid better — more like doctors and lawyers. In 2009, the Equity Project, a charter school in New York decided to try it: they would pay all their teachers $125,000 per year with the possibility of an additional bonus.

The typical teacher in New York with five years' experience makes between $64,000 and $76,000. The charter school, known as TEP, would pay much more. But in exchange, teachers, who are not unionized, would accept additional responsibilities, and the school would keep a close eye on their work.

Four years later, students at TEP score better on state tests than similar students elsewhere. The differences were particularly pronounced in math, according to a study from Mathematica Policy Research released in October. (The study was funded by the Gates Foundation.) After four years at the school, students had learned as much math as they would have in 5.6 years elsewhere:

(Mathematica Policy Research)

The gains erased 78 percent of the achievement gap between Hispanic students and whites in the eighth grade.

The results are important in part because TEP also appears to have sidestepped some common concerns about charter schools. They didn't expel or suspend students out of school in the first four years. There is no evidence that the school encouraged problem students to leave or transfer on their own. And the students who attended were roughly as likely to be low-income, and to have had similar levels of academic achievement before they arrived. They could still differ in other ways — they could have more involved parents, who get them into the charter school lottery, for example — but TEP doesn't present some of the obvious factors that help explain other charter schools' success.

How TEP hired and trained teachers

The $125,000 number was eye-catching, but it was just the start of the school's approach to teaching. Teachers were also eligible for a bonus of between 7 to 12 percent of their salary. The teachers, who are not unionized, went through a rigorous selection process that included a daylong "audition" based on their teaching skills. The typical teacher already had six years of classroom experience before they were hired.

Teachers at TEP also get more time to collaborate and played a bigger role in school decision-making than teachers in other jobs. Teachers were paired up to observe each others' lessons and provide feedback, collaboration that experts agree is important but happens too infrequently. During a six-week summer training, teachers also helped set school policy.

The workload at TEP, where teachers also take on administrative duties and had an average of 31 students per class, is fairly heavy even with the extra pay. But the school also had more teacher turnover than usual. Nearly half of first-year teachers didn't return for their second year, either because they resigned or because they were not rehired. Teacher turnover has been found to have a slight effect on student achievement.

Overall, though, the results are promising. The researchers caution that this is just one study of a small school. It's not meant to prove that TEP's methods can work in every school nationally. But it appears to suggest that, at least, the approach worked at one school.