Secondary School Students' Reasoning about Conditional Probability, Samples, and Sampling Procedures

In the Australian mathematics curriculum, Year 12 students (aged 16-17) are asked to solve conditional probability problems that involve the representation of the problem situation with two-way tables or three-dimensional diagrams and consider sampling procedures that result in different correct answers. In a small exploratory study, we investigate three Year 12 students' conceptions and reasoning about conditional probability, samples, and sampling procedures. Through interviews with the students, supported by analysis of their work investigating probabilities using tabular representations, we investigate the ways in which these students perceive, express, and answer conditional probability questions from statistics, and also how they reason about the importance of taking into account what is being sampled and how it is being sampled. We report on insights gained about these students' reasoning with different conditional probability problems, including how they interpret, analyse, solve, and communicate problems of conditional probability.