The National Academies of Sciences, Engineering, and Medicine has a new consensus report on teacher preparation. One of their conclusions says this (emphasis added):

The research base on preservice teacher preparation supplies little evidence about its impact on teacher candidates and their performance once they are in the classroom. Preservice programs in many states assess the performance of teacher candidates for purposes of licensure, but few states have developed data systems that link information about individual teachers’ preservice experiences with other data about those teachers or their performance. Overall, it is difficult to assess the causal impact of teacher preparation programs.

–Guest post by Chad Aldeman