## Preprint: Fair coins tend to land on the same side they started: Evidence from 350,757 flips

This post is a synopsis of Bartoš et al. (2023). Fair coins tend to land on the same side they started: Evidence from 350,757 flips. Preprint available at https://doi.org/10.48550/arXiv.2310.04153. Post-specific images were generated by Bing. Abstract Many people have flipped coins but few have stopped to ponder the statistical and physical intricacies of the process. In a preregistered study we…

## The Tomb of Thomas Bayes in 2023

In July this year, my friend and long-term collaborator Michael Lee visited the grave of Thomas Bayes at Bunhill Fields in London. When Michael showed me the photo I was shocked. This is what Bayes’ tomb looks like in 2023: Overgrown with moss and generally in a sorry state, this is hardly a worthy monument to the man who pioneered…

## The Psi of Eros

This is a DeepL-assisted translation of an article for the Dutch magazine Skepter (Wagenmakers, 2023). I am grateful to the editor, Hans van Maanen, for his efforts in rewriting my original draft. The painting is a self-portrait by René Magritte called ‘La Clairvoyance’ (1936 – proposed by van Maanen to accompany the article).  TLDR;  Can psychology students really anticipate the appearance…

## Order-restrictions in JAGS: Five Methods Fail, One Method Succeeds

TL;DR When implementing order-restrictions in JAGS, only the “ones trick” appears to yield the correct result. Consider two unknown chances, $\theta_1$ and $\theta_2$, that are assigned independent beta priors: $\theta_1 \sim \text{beta}(1,1)$ and $\theta_2 \sim \text{beta}(1,1)$. Let’s visualize the joint posterior by executing JAGS code (Plummer, 2003) and plotting the samples that are obtained from the MCMC algorithm. This is…

## What Determines the Price of LEGO Sets? A Bayesian Analysis with Twists and Turns

Recently we completed a multi-year Odyssey in order to obtain Bayes factors for partial correlations. The result is now available as a preprint. Instead of delving into the finer details of Bayes factors and posterior distributions, we will provide a concrete demonstration. Specifically, we will use Bayes factors for partial correlations to address a perennial question that has tormented children…

## Visualizing the Equation for the Sample Correlation Coefficient

TL;DR We just preprinted a manuscript on how to teach the correlation coefficient with rectangles and squares. Check out the cool pictures. Suggestions for improvement are welcome. Abstract The equation for the Pearson correlation coefficient can be represented in a scatter plot as the difference in area between concordant and discordant rectangles, scaled by an area that represents the maximum possible…