Courtney Bell serves as the Director of the Wisconsin Center for Education Research and Professor of Learning Sciences at the University of Wisconsin–Madison. A former high school science teacher, Courtney earned her doctorate at Michigan State University in curriculum, teaching and educational policy and a B.A. in chemistry at Dartmouth College. Courtney is passionate about understanding and improving teaching for historically underserved children. Her interdisciplinary collaborative work is situated at the intersections of research, policy and practice. It spans issues of parental choice, performance assessments of teaching, international comparisons of teaching, teaching quality, teacher learning, teacher education, and the measurement of teaching. Courtney was proud to lead the international development of two observation systems and serve as a PI on the OECD-organized TALIS Video Study (also called the Global Teaching InSights study). This ground-breaking study was the first of its kind to comprehensively measure teaching quality using observations, artifacts, questionnaires, and student outcomes in eight economies. Courtney’s talk will use data from four studies of teaching quality that involve more than 8,000 teachers across continents. She will show how teaching quality’s definition, operationalization, and use by practitioners present significant tradeoffs. Researchers must be aware of and manage these tradeoffs if they are to make valid research claims and support the improvement of teaching.