How do I know what my theory predicts? by Prof Zoltan Dienes

About the speaker

Zoltan Dienes is a Professor of Experimental Psychology at the University of Sussex. His research interests are in exploring ways of changing common practice in statistical inference by using Bayesian methods. He is also interested in the distinction between conscious and unconscious mental states, as well as hypnosis, a way of acting which he argues is intentional but the person is strategically unaware of those intentions.

About the talk

To get evidence for or against one’s theory relative to the null hypothesis, one needs to know what it predicts. The amount of evidence can then be quantified by a Bayes factor. It is only when one has reasons for specifying a scale of the effect that the level of evidence can be specified for no effect. In many papers people declare the absence of an effect while having no rational grounds for doing so.  So we need to specify what scale of the effect our theory predicts. Specifying what one’s theory predicts may not come naturally, but Prof Dienes shows ways of thinking about the problem, some simple heuristics that are often useful, including the room-to-move heuristic and the ratio-of-scales heuristic.