Logic / Unit 7 Logic 350 short lesson, about 20 seconds
Base Rates
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The idea
The base rate is how common something is before any specific evidence. Ignoring it makes rare things look common whenever tests can err.
In practice
A rare condition plus a decent test still yields mostly false alarms — rarity outvotes accuracy.
Where people slip
Base-rate neglect is the reasoning error with the highest real-world body count: medicine, security, hiring.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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