Courtney Bell is a Principal Research Scientist in ETS’s Global Assessment Center. She completed her doctorate at Michigan State University in Curriculum, Teaching, and Educational Policy after earning her B.A. in Chemistry at Dartmouth College. A former high school science teacher and teacher educator, Courtney’s work focuses on the measurement of teaching and how measures of teaching are understood and used in research, policy and practice communities. Her studies use mixed-methods to analyze the measurement of teaching and the validity of measures of teaching quality focusing in particular on observational assessments of teaching. Current and recent studies funded by the Institute for Educational Sciences, the National Science Foundation, and the Gates, W.T. Grant and Spencer Foundations investigate how administrators learn to use a high stakes observation protocol, how measures of teaching compare across countries, indicators of teaching quality, and the ways in which observation protocols capture high quality teaching for students with special needs.