Margaret (Peg) Smith is a Professor Emerita at University of Pittsburgh. Over the past three decades she has been developing research-based materials for use in the professional development of mathematics teachers. She has coauthored several books including Five Practices for Orchestrating Productive Discussions (with Mary Kay Stein), the middle and high school versions of the Taking Action series (with Melissa Boston, Fredrick Dillon, Stephen Miller, and Lynn Raith), and The 5 Practices in Practice: Successfully Orchestrating Mathematics Discussion in Your Classroom series (with Victoria Bill, Miriam Gameron Sherin, and Michael Steele). In 2006 she received the Chancellor’s Distinguished Teaching Award given annually to honor outstanding faculty at the University of Pittsburgh. In 2009 she received the award for Excellence in Teaching in Mathematics Teacher Education from AMTE. In April 2019 she received the Lifetime Achievement Award from NCTM.Bilge Yurekli is a research associate at the University of Pittsburgh’s Learning Research and Development Center. She holds a PhD in mathematics education. Her research focuses on mathematics teacher education, at both pre-service and in-service levels, with a specific interest in teacher development of beliefs and practices that is required for high-quality instruction. She has worked with Mary Kay Stein and her multidisciplinary team of researchers on various projects supported by NSF, IES, Spencer and McDonnell Foundations. Her research has been published in NCTM’s Journal for Research in Mathematics Education and presented at both national and international research conferences, including NCTM and AERA. Currently, she is working on a project that aims to promote productive struggle in mathematics classrooms.Mary Kay Stein is Professor Emerita at the University of Pittsburgh where she held a joint appointment as Professor in the School of Education and Senior Scientist at the Learning Research and Development Center. Her research focuses on the teaching and learning of mathematics in elementary and middle schools with a particular focus on the identification and implementation of high-cognitive-demand instructional tasks. She also examines school- and district-level factors that shape teachers’ capacities to maintain high levels of cognitive demand once tasks are launched in the classroom. Her research has been supported by IES (the Institute of Education Sciences) as well as by several private foundations including the MacArthur, Spencer and McDonnell Foundations. In addition to co-authoring the Five Practices book (with Peg Smith), she has co-authored a book and several articles about district-wide reform. She has given invited addresses to both national and international audiences including in Beijing, Seoul, Goteborg, Hamburg, Istanbul, Haifa, and Lisbon. She also served as a Visiting Scholar at Monash University in Melbourne, Australia in 2012. In 2014, she was named a Fellow of the American Educational Research Association.