organisational behavior and human decision processes 54, 45-56 (1993)

Predictive Judgments in Situations of Statistical Analysis

Marie-Paule Lecoutre and Henry Rouanet

Groupe Mathématiques et Psychologie, Université René Descartes

Probabilistic judgments made by researchers in psychology were investigated in statistical prediction situations. From these situations, it is possible to test the “representativenes hypothesis” (Tversky & Kahneman, 1971) and the “significance hypothesis” (Oakes, 1986). The predictive judgments concerned both an elementary descriptive statistic and a significance test statistic. In the first case, the predictive judgments were generally coherent and fit comparatively well to Bayesian standard predictive probabilities. In the second case, they were generally incoherent and fit poorly to Bayesian standard predictive probabilities. As for the two hypotheses tested, our findings are compatible with the significance hypothesis, but go against the representativeness hypothesis.