?Professor Yoshinori Shimizu, Ph. D, is a mathematics educator who works at Graduate School of Comprehensive Human Sciences of University of Tsukuba, one of the major research institutions in Japan. He finished his Ph.D in Mathematics Education at Doctoral Program in Education, University of Tsukuba. He has been working at institutions such asTokyo Gakugei University, Indiana University (USA) as visiting scholar, and University of Tsukuba He was a member of Mathematics Expert Group (MEG) for OECD/PISA 2003, 2006, 2009. He was a consultant for 1995 TIMSS Videotape Classroom Study. He is one of the founders of Learner’s Perspective Study (LPS), a sixteen countries comparative study on mathematics classrooms and has been the Japanese team leader of the project. He was a member of the International Committee of the International Group for the Psychology of Mathematics Education (2005-2009). He is the vice president of Japan Society of Mathematical Education. He was the co-chair forthe ICMI Study 24 conference held in November 2018 in Tsukuba, Japan.Professor Renuka Vithal is the former Deputy Vice-Chancellor for Teaching and Learning, Dean of Education and Professor of Mathematics Education of the University of KwaZulu-Natal; and is currently Deputy Vice-Chancellor for Academic Affairs at Fort Hare Univeristy. She is also a member of the Board of Trustees of CASME. Professor Vithal obtained her MPhil in mathematical education from the University of Cambridge in the United Kingdom and her doctoral degree in natural sciences from Aalborg University in Denmark. She began her career as a mathematics teacher and proceeded to work for institutions such as the University of Durban Westville and University of KwaZulu-Natal where she attained full professorship in mathematics education. She is recognised internationally as a scholar in the social, cultural and political dimensions of mathematics education.