Interpretation of significance levels by psychological researchers: the .05 cliff effect may be overstated.
Comments about previous studies indicate that the interpretation of significance levels by psychological researchers is unequivocally dictated by a binary decision-making framework. In particular, confidence in a p level would drop abruptly just beyond the fateful .05 level (cliff effect). A replication of Rosenthal and Gaito's (1963) experiment on the degree of confidence in p levels shows that these claims should be moderated. Detailed analysis of individual curves reveals that the attitude of researchers toward p values is far from being as homogeneous as might be expected. However, most psychological researchers in our study rated graduated confidence judgments, as either exponential or linear. Only a minority of all-or-none respondents exhibited an abrupt drop in confidence.
Poitevineau
J
J
Centre National de la Recherche Scientifique, Paris, France. jacques.poitevineau@ivry.cnrs.fr
Lecoutre
B
B
D003657:Decision Making; D006801:Humans; D008962:Models, Theoretical; D011584:Psychology / Q000379:methods; D011897:Random Allocation