Examining High and Low Value-Added Mathematics Instruction: Can Expert Observers Tell the Difference

The question of how to measure effective teachers and teaching has long been of interest to policymakers and school leaders. While recent policy initiatives have focused on the use of value-added measures (VAM) to assess teacher quality, there is a much longer tradition of using observations of practice to make such determinations. However, empirical evidence suggests these two indicators often identify different sets of teachers as effective. For example, the Measures of Effective Teaching project finds low correlations between teachers’ VAM scores and their quality of instruction as measured by observational metrics. Studies with the explicit intent of identifying differences in instruction between teachers with high and low VAM scores also have generally failed to uncover substantial differences across classrooms. In this study, we take advantage of a dataset containing both videotaped lessons and value-added scores to mount an exploratory study of the instruction of teachers with high- and low-value-added rankings. Specifically, we seek to answer two questions: First, what is the degree of convergence between observers’ impressions of mathematics instruction and teachers’ mathematics value-added scores? Second, are there a set of instructional practices that consistently characterize high but not low-value-added ranked teachers’ classrooms, and vice versa?