The Licensed Crossing
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
Bayes' rule converts reasoning from causes into reasoning toward them: nature hands agents likelihoods — how often a condition produces a sign — while agents need posteriors: which condition, given the sign.
Show
Diagnosis, spam filtering, and speech recognition are all this crossing performed at scale.
Watch for
The crossing's toll is the prior — forget it and you have transposed the conditional, not crossed it.