Professor John Hattie is Director of the Melbourne Educational Research Institute at the University of Melbourne, Chair of the Australian Institute of Teaching and School Leaders, co-director of the Science of Learning Research Centre. His areas of interest are measurement models and their applications to educational problems, and models of teaching and learning. Previous appointments were in Auckland, North Carolina, Western Australia, and New England. He was chief moderator of the NZ Performance Based Research Fund, Past-President of the International Test Commission, associate editor of British Journal of Educational Psychology, and American Educational Research Journal, and is part-time cricket coach and umpire. He has published and presented over 850 papers, and supervised 180 theses students.