If you want to judge the quality of a teacher prep program, one approach is obvious: examine whether the teachers who graduate from that program actually help students learn.

Easier said than done. Many factors affect whether a teacher will succeed in the classroom, and determining how training factors into that success requires more data and statistical power than is typically available. That's one of the reasons that academic researchers, states, accreditation agencies, and NCTQ's Teacher Prep Review assess prep programs mainly by measuring the program features known to influence teacher quality—such as admissions standards and what teacher candidates are being taught about reading instruction.

A new study from Paul T. von Hippel (UT-Austin) and his colleagues is among the most promising of the few studies that have sought to measure the direct impact of individual prep programs on student learning. Thanks to cooperation with the Texas Education Agency, he was able to examine outcomes across thousands of teachers and hundreds of thousands of students in the nation's second-largest state.

Unfortunately, even with this much data, they turned up little new evidence that one teacher prep program is better than another.

Given the impressive load of data that von Hippel et al. had at their disposal, this conclusion raises some red flags. The data set is unprecedented in size and includes a diverse set of traditional and alternative prep programs. Given this variety, it is reasonable to expect to be able to pinpoint at least a few obviously high or low performers. Instead, we see more evidence that many of the challenges in teacher prep likely exist across the board. It's a finding not unlike NCTQ's own much different scan of the landscape in which 80 percent of all teacher prep programs earned scores classifying them as weak or failing. 

The study authors use these results to warn policymakers against using student outcomes data to make decisions about program expansion and closure, reasoning that the programs were all too similar for anyone to be sure they were singling out the right ones. We're hoping Texas policymakers will start asking a new question: Why are programs continuing to operate without clear and specific standards for what teachers should know and be able to do?