Details

Autor(en) / Beteiligte

• Wetzels, Ruud
• Matzke, Dora
• Lee, Michael D.
• Rouder, Jeffrey N.
• Iverson, Geoffrey J.
• Wagenmakers, Eric-Jan

Titel

Statistical Evidence in Experimental Psychology: An Empirical Comparison Using 855 t Tests

Ist Teil von

• Perspectives on Psychological Science, 2011-05, Vol.6 (3), p.291-298

Ort / Verlag

Los Angeles, CA: Sage Publications

Erscheinungsjahr

2011

Quelle

Applied Social Sciences Index & Abstracts (ASSIA)

Beschreibungen/Notizen

• Statistical inference in psychology has traditionally relied heavily on p-value significance testing. This approach to drawing conclusions from data, however, has been widely criticized, and two types of remedies have been advocated. The first proposal is to supplement p values with complementary measures of evidence, such as effect sizes. The second is to replace inference with Bayesian measures of evidence, such as the Bayes factor. The authors provide a practical comparison of p values, effect sizes, and default Bayes factors as measures of statistical evidence, using 855 recently published t tests in psychology. The comparison yields two main results. First, although p values and default Bayes factors almost always agree about what hypothesis is better supported by the data, the measures often disagree about the strength of this support; for 70% of the data sets for which the p value falls between .01 and .05, the default Bayes factor indicates that the evidence is only anecdotal. Second, effect sizes can provide additional evidence to p values and default Bayes factors. The authors conclude that the Bayesian approach is comparatively prudent, preventing researchers from overestimating the evidence in favor of an effect.