Publications by Daniel Lakens
Dance of the Bayes factors
You might have seen the ‘Dance of the p-values’ video by Geoff Cumming (if not, watch it here). Because p-values and the default Bayes factors (Rouder, Speckman, Sun, Morey, & Iverson, 2009) are both calculated directly from t-values and sample sizes, we might expect there is also a Dance of the Bayes factors. And indeed, there is. Bayes fact...
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Why Within-Subject Designs Require Fewer Participants than Between-Subject Designs
One widely recommended approach to increase power is using a within subject design. Indeed, you need fewer participants to detect a mean difference between two conditions in a within-subjects design (in a dependent t-test) than in a between-subjects design (in an independent t-test). The reason is straightforward, but not always explained, and e...
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TOST equivalence testing R package (TOSTER) and spreadsheet
I’m happy to announce my first R package ‘TOSTER’ for equivalence tests (but don’t worry, there is an old-fashioned spreadsheet as well). In an earlier blog post I talked about equivalence tests. Sometimes you perform a study where you might expect the effect is zero or very small. So how can we conclude an effect is ‘zero or very small...
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Why Type 1 errors are more important than Type 2 errors (if you care about evidence)
After performing a study, you can correctly conclude there is an effect or not, but you can also incorrectly conclude there is an effect (a false positive, alpha, or Type 1 error) or incorrectly conclude there is no effect (a false negative, beta, or Type 2 error). The goal of collecting data is to provide evidence for or against a hypothesis. T...
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ROPE and Equivalence Testing: Practically Equivalent?
In a previous post, I compared equivalence tests to Bayes factors, and pointed out several benefits of equivalence tests. But a much more logical comparison, and one I did not give enough attention to so far, is the ROPE procedure using Bayesian estimation. I’d like to thank John Kruschke for feedback on a draft of this blog post. Check out his...
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