Last year, an Urban Institute study looked at Teach for America (TFA) teachers in North Carolina and concluded that they were more effective than their non-TFA colleagues.

In response to critics, the authors of the study released a revised report that features a significantly larger sample of North Carolina students and teachers. The result?

The results were the same: Across the eight subjects tested, the students of TFA teachers racked up bigger learning gains than their non-TFA counterparts.

The TFA teachers were also found to be more effective than teachers who had graduated from a fully accredited North Carolina teacher-training program and those who were licensed in the subjects they taught. The overall TFA boost, in fact, was bigger than the size of the learning improvement that students normally get from having a teacher who’s been on the job for three years or more.

Some specifics from the study include the following:

– Other things being equal, the findings suggest that disadvantaged students taught by TFA teachers are better off than they would be in the absence of TFA.

– To examine this question [TFA vs. fully licensed math and science teachers] we restricted the comparison to traditional teachers who were fully certified in field. The TFA advantage still held.

– Disadvantaged secondary students would be better off with TFA teachers, especially in math and science, than with fully licensed in-field teachers with three or more years of experience.