20 PEOPLE’S INTUITIONS ABOUT RANDOMNESS AND PROBABILITY: AN EMPIRICAL STUDY4 MARIE-PAULE LECOUTRE ERIS, Université de Rouen
[email protected] KATIA ROVIRA Laboratoire Psy.Co, Université de Rouen
[email protected] BRUNO LECOUTRE ERIS, C.N.R.S. et Université de Rouen
[email protected] JACQUES POITEVINEAU ERIS, Université de Paris 6 et Ministère de la Culture
[email protected] ABSTRACT What people mean by randomness should be taken into account when teaching statistical inference. This experiment explored subjective beliefs about randomness and probability through two successive tasks. Subjects were asked to categorize 16 familiar items: 8 real items from everyday life experiences, and 8 stochastic items involving a repeatable process. Three groups of subjects differing according to their background knowledge of probability theory were compared. An important finding is that the arguments used to judge if an event is random and those to judge if it is not random appear to be of different natures. While the concept of probability has been introduced to formalize randomness, a majority of individuals appeared to consider probability as a primary concept. Keywords: Statistics education research; Probability; Randomness; Bayesian Inference 1. INTRODUCTION In recent years Bayesian statistical practice has considerably evolved. Nowadays, the frequentist approach is increasingly challenged among scientists by the Bayesian proponents (see e.g., D’Agostini, 2000; Lecoutre, Lecoutre & Poitevineau, 2001; Jaynes, 2003). In applied statistics, “objective Bayesian techniques” (Berger, 2004) are now a promising alternative to the traditional frequentist statistical inference procedures (significance tests and confidence intervals). Subjective Bayesian analysis also has a role to play in scientific investigations (see e.g., Kadane, 1996).