Heymans Colloquium: Prof. Z.Dienes, Using Bayes to get the most out of null results

LECTURER Professor Zoltan Dienes (University of Sussex, United Kingdom)

TITLE Using Bayes to get the most out of null results

DATE & TIME Tuesday, 29 April 2013, 13.00 – 14.00 hrs

LOCATION Room M.0161, Munting Building, Grote Kruisstraat 2/1, Groningen

ABSTRACT User's of orthodox statistics, including psychologists, have typically not interpreted null results in a principled way, resulting in mistaken conclusions and choices of research direction based on non-significant findings. A non-significant result does not distinguish no evidence for an effect from evidence for no effect, radically different states of affairs. The distinction falls out naturally from a Bayesian analysis, in a consistent way that cannot be accomplished with orthodox statistics, even when statistical power is taken into account. I will show how simple free online software for calculating Bayes Factors can be used to determine what a null result is actually telling us. The tools I introduce in this talk, and now gradually appearing in the literature, should enable publishing null results on an equal footing with significant results. I hope to make people aware of a genuine practical hole in current practice in any domain of psychology and offer a genuine prac! tical so lution. The talk will be useful to anyone who uses inferential statistics. No statistical background is assumed other than knowledge of how to do a t-test.