Informations and abstract
Keywords: P-value; Effect Size; Norme APA; Null Hypothesis Significance Testing.
In this paper we studied the use of inferential statistics in the "Italian Journal of Psychology". By means of an automated procedure, all articles published from 1997 to 2012 that presented statistical results along with at least one "p-value" were selected. The most commonly used statistics turned out to be F, t and |2 (about 70% of the total), and their frequency of use remained stable throughout the period here considered. Where possible, we recalculated the "p-values", compared them with those reported by the authors, and analyzed the overall distribution. Finally, applying a Bayesian procedure, the effect size estimates were assessed.