Visualising Conditional Probabilities—Three Perspectives on Unit Squares and Tree Diagrams

Abstract

Two visualisations, i.e. the tree diagram and the unit square, are discussed from three perspectives of our research programme concerning possibilities of facilitating the understanding of Bayesian situations. We first regard the psychological perspective focusing on people’s ability to solve specific tasks in Bayesian reasoning situations. Second, we discuss the educational perspective, where a visualisation has not only the goal to solve specific tasks but to understand the structure of a mathematical concept. Finally practical considerations for the every-day classroom constitute our third perspective. For each of these perspectives we compare the tree diagram and the unit square concerning their efficiency. Results imply that the unit square is more efficient from a psychological perspective and an educational perspective, and is on a similar level of efficiency when the practical perspective is regarded.