The Authors: Wolff-Michael Roth is Lansdowne Professor of Applied Cognitive Science at the University of Victoria. His interests are broad and concern science and science learning in formal (elementary school to university) and informal settings (community activities, research laboratories). After leaving the high school level in 1992, he has continued to teach science at the elementary and middle school level. Kenneth Tobin is Professor of Education at the University of Pennsylvania. His main research is concerned with the improvement of teaching and learning in urban schools. Committed to «walking the walk,» he coteaches with resident teachers in inner-city schools of Philadelphia. Steve Ritchie is Senior Lecturer in Science Education at the James Cook University in Townsville, Queensland. His interests are in classroom research, where he works closely with teachers in order to assist them in the transformation of their practices.