The development of conditional probability reasoning

Although errors in reasoning about conditional probability have been the focus of interest of psychologists for a long time, the development of conditional reasoning in school students has received little attention. This paper considers the responses of 69 students across grades 3 to 13 in an attempt to model the development of appropriate reasoning skills. Although acknowledging the misconceptions observed by earlier researchers, this study seeks a positivist approach to describe developing understanding by combining mathematical appropriateness with structural complexity. The results of the study are intended to inform other researchers, teachers, and curriculum developers.