Another Brief Test of Your Bayesian Intuition: The Answer

In a previous blog post, we proposed the following test of your Bayesian intuition: Three friends –Alex, Bart, and Cedric– each assign their own prior distribution to a binomial chance parameter θ. Let’s say that θ is the chance that Harriet bakes a vegan pancake rather than a bacon pancake. Alex assigns θ a beta(300,3) prior distribution, indicating a strong…

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Another Brief Test of Your Bayesian Intuition

Three friends –Alex, Bart, and Cedric– each assign their own prior distribution to a binomial chance parameter θ. Let’s say that θ is the chance that Harriet bakes a vegan pancake rather than a bacon pancake. Alex assigns θ a beta(300,3) prior distribution, indicating a strong belief in high values of θ (i.e., Alex predicts that almost all of Harriet’s…

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How to Memorize Bayes’ Rule

Bayes’ rule dictates how new data update the credibility of competing accounts of the world . An immediate consequence of the definition of conditional probability, Bayes’ rule is usually presented as follows: The way I mentally check this equation is to take the denominator of the expression on the right-hand side, , and multiply it with the left side of…

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Aleatory Uncertainty and the River Rubicon

Mounted on a bridge across the river Rubicon, the bust of Julius Caesar eyes the Adriatic sea. Caesar’s nose is shiny, perhaps (but his is speculative, based on limited observations) because passersby feel tempted to touch it with their index finger. A high resolution version is available here (CC-BY). Photo taken by Eric-Jan Wagenmakers, August 4, 2024. In 49 BC,…

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Origin of the Texas Sharpshooter II: The Dubner Maggid

The picture of the Texas sharpshooter  is available in our artwork library (CC-BY). Artwork by Dirk-Jan Hoek, concept by Eric-Jan Wagenmakers. In a 2018 blog post I mentioned that it is unclear who first came up with analogy of the Texas sharpshooter: The infamous Texas sharpshooter fires randomly at a barn door and then paints the targets around the bullet…

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Clarkson’s Farm and the Clarkson Ring

The hit series “Clarkson’s Farm” has Jeremy Clarkson attempt farming, in a highly amusing mix between Mr. Bean, John Cleese in Clockwise, and Pat & Mat. After binge-watching the first three seasons, I was struck by one particular topic: the mass death of the piglets. Clarkson houses his sows in “pigloos” — dome-shaped pig farrowing pens. The first time the…

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