This new study asks a question that is receiving increasing attention: How does teacher preparation affect student achievement? To answer it, the authors gathered data from about 22,078 North Carolina educators, including how teachers were prepared and characteristics of the schools where they teach. This was combined with five years of test score data from 1.18 million students. The study is more robust than similar research, owing to its comprehensive data set and the way that it grouped teachers: Instead of lumping teachers into two broad groups—traditional or alternative certification—it creates much more nuanced groups of teachers by the way they were prepared, as well as by grade and subject taught. The first comparison is between teachers who were traditionally prepared to those who received alternative certification (meaning they didn’t have a full credential when they began teaching), excluding teachers prepared by Teach For America. Alternative entry teachers are significantly less effective (as determined by value-added measures) than traditionally prepared teachers in middle school math and high school math and science. There was no difference in the other grade levels and subjects. Second, compared to traditionally-prepared teachers, TFA teachers are more effective in six of the eight categories: elementary math and reading, middle school math, and high school math, science, and English. Third, teachers prepared out of state are less effective than those prepared in state in elementary math and reading and high school math. Fourth, teachers who began teaching with a graduate degree are less effective in middle school math and reading, but more effective in high school science. Fifth, and finally, there was no difference in any grade level or subject between in-state teachers who received their certification from private versus public schools. The study also confirms previous research that shows that there’s significant variation in teacher effectiveness within different preparation categories, not just between them. Unfortunately, it’s difficult to draw a clear conclusion about state policy based on the findings. Quality control is necessary, but creating barriers to entry into the teaching workforce can keep out some of the very people who would serve students best. Individual teacher candidates should be judged on their own merits, no matter how they are prepared (and preparation programs, regardless of their format, should be rigorous). Assessing teacher quality requires schools and districts to evaluate their merits rigorously before and after teachers enter the classroom, as opposed to assuming a teacher is good at their job simply because of how they’re prepared.
SOURCE: Gary T. Henry, et al., "Teacher Preparation Policies and Their Effects on Student Achievement," The Association for Education Finance and Policy (2014).