Bayes to the rescue: does the type of hypnotic induction matter?

Martin, Jean-Rémy and Dienes, Zoltan (2019) Bayes to the rescue: does the type of hypnotic induction matter? Psychology of Consciousness: Theory, Research, and Practice. ISSN 2326-5523 (Accepted)

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Studies comparing different forms of hypnotic induction (e.g., indirect versus direct induction) on responsiveness to suggestion have typically found no significant difference between induction types. However, no firm conclusion can be drawn from a non-significant result. In contrast, Bayes factors (Jeffreys, 1939) indicate whether evidence favors the null hypothesis (H0) and against the alternative hypothesis (H1), or whether data are simply insensitive. Here we apply Bayes factors to those non-significant results in order to decide: does the form of hypnotic induction really not matter, does it matter, or should we suspend judgment? As the claim that different inductions are differentially effective comes mostly from clinicians, we based the Bayes factors on hypnotherapists’ judgments of expected differences between inductions. In addition, we also used empirical differences between induction versus no-induction as an estimate of the order of size of effect that could be expected between different inductions, independent of clinical judgment. As a whole, the Bayesian re-analysis of the present evidence supports the claim that additional research should be done on the influence of the induction procedure on hypnotic responsiveness (at least with regard to the inductions considered in the present study), with severalexceptions.

Item Type: Article
Keywords: Hypnosis; hypnotic induction; Bayesian statistics; Bayes factors
Schools and Departments: School of Psychology > Psychology
School of Mathematical and Physical Sciences > Physics and Astronomy
Depositing User: Sanjeedah Choudhury
Date Deposited: 28 Feb 2019 14:27
Last Modified: 28 Feb 2019 15:11

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