David Blazar is a second-year doctoral student in quantitative policy analysis at the Harvard Graduate School of Education. His research interests include measurement of teacher effectiveness and evaluations of training programs aimed at improving teacher effectiveness. Currently, he works with the National Center for Teacher Effectiveness to design and test the validity of scores from the Mathematical Quality of Instruction instrument to assess elementary school math instruction. He also is working on an evaluation of a teacher-coaching program for early career teachers. Prior to entering the doctoral program, David taught high-school English Language Arts in New York City. He also worked as a research assistant at the Community College Research Center at Teachers College, where he examined student progression through the remedial math sequence at community colleges in Virginia. David holds an Ed.M. in policy and management from the Harvard Graduate School of Education and a B.A. in history and literature from Harvard College.