Shouldn't we expect that teachers will initially perform differently in the classroom based on the quality of their preparation? After all, there are no fewer than 1,400 institutions of higher education in the U.S. (not to mention a burgeoning market of alternative routes) purporting to prepare teachers, setting the stage for huge variations in teacher training.

Maybe not, suggests new research from AIR's CALDER. Authors Koedel, Parsons, Podgursky and Ehlert (you may remember this study from the attention it received as a working paper back in 2012) report it is difficult to attribute swings in teacher effectiveness to the institutions which prepared teachers and that big variations exist among teachers who graduated from the same institution. Of differences noted among teachers from different institutions, only one to three percent of that variation was explained by which institution the teachers attended. 

What might explain this breach in logic? 

It could be that institutions' approaches to teacher preparation are more similar than their numbers suggest or common sense would presume. NCTQ's analysis in the Teacher Prep Reviewbacks up this hypothesis, finding the vast majority of institutions (81 percent) in the United States can be classified as "weak" or "failing." If an overwhelming number of programs are not providing what teachers need to be moderately successful when they walk into a classroom—essentially not adding value to their candidates' own preparation—then teachers will be only as effective as the raw attributes they bring to the table. No wonder Koedel et al were unable to capture institutions which have a meaningful and consistent impact on their teacher candidates: too few of them do.

The authors provide some evidence for this hypothesis. None of the 11 institutions in the sample demonstrated much selectivity in their teacher prep program admissions process, and notably less so than other programs of study on their campuses. This practice of setting a very low floor for entry (widespread across the country) results in huge differences—at least in terms of academic ability— in the quality of teacher candidates attending the same program. Overall, selectivity did not appear to be as important in admission to teacher preparation programs as it was in other programs of study at these institutions.