BRIAN GREER is Professor at the San Diego State University, working in the Centre for Research on Mathematics and Science Education. He has taught statistics to psychology students for many years, and has published widely on mathematics education, recently co-authoring Making Sense of World Problems. GERRY MULHERN is Senior Lecturer in Psychology at Queen's University of Belfast, having previously taught at the Universities of Edinburgh and Ulster. He has published widely in the areas of applied cognition and mathematics education, and is former Honorary General Secretary of the British Psychological Society.