THE WORLD OF DR. BAYESA WORK IN PROBABILITY · EST. 2026
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THE ARCHIVE/EPISODE 004
EPISODE 004 · THE POSTERIOR

A Quick Learner

The student becomes the statistician. A short lesson in priors and posteriors backfires when the bartender starts checking the evidence.

PriorsPosteriorsThe Bartender
THE COMICTap any panel to open it at full size
Episode 004 of the Dr. Bayes comic, “A Quick Learner”: A short lesson in priors and posteriors backfires when the bartender starts checking the evidence. The full dialogue is in the transcript below.
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A NOTE FOR CURIOUS MINDS

Behind the joke.

The bartender understands the mechanics immediately: start with a belief, observe relevant evidence and revise the belief. His accumulated bar tab is the new evidence that changes his view of Dr. Bayes's motives. The student has become a fairly perceptive Bayesian.

SPEECH BUBBLES, IN WORDS

The transcript.

For readers who prefer dialogue without zooming in.

Read the dialogue ↘

Bartender: So, a prior is what you believe before seeing the data?

Dr. Bayes: Exactly.

Bartender: And a posterior is what you believe after seeing the data?

Dr. Bayes: You're catching on.

Bartender: My prior was that you came here for the whiskey.

Bartender: My posterior is that you came here for the credit.