National Board Certification and Teacher Effectiveness: Evidence from a Random Assignment Experiment

The National Board for Professional Teaching Standards (NBPTS) assesses teaching practice based on videos and essays submitted by teachers. We compared the performance of classrooms of elementary students in Los Angeles randomly assigned to NBPTS applicants and to comparison teachers. We used information on whether each applicant achieved certification, along with information on each applicant's NBPTS scaled score and subscores, to test whether the NBPTS score was related to teacher impacts on student achievement. We found that students randomly assigned to highly-rated applicants performed better than students assigned to comparison teachers, while students assigned to poorly-rated applicants performed worse. Estimates were similar using data on pairs of teachers that were not randomly assigned. Our results suggest a number of changes that would improve the predictive power of the NBPTS process.