Abstract

The purpose of this work is to alert the Italian clinical psychology research community that reporting Null Hypothesis Significance tests is insufficient when presenting experimental results. This article: 1) describes the current debate regarding the use of statistical significance tests; 2) illustrates various types of significance considered in the literature; 3) provides a survey of measures that establish the size of an effect. In accordance with the recommendations of the Fifth Edition of the APA Manual, 2001, we strongly recommend considering the practical significance of an effect. Researchers should always report one or more indices of both statistical and practical significance, readers should expect the presentation of these indices, and editorial policies should require their inclusion in published papers.