Prior Belief

The sealed record

What you believed before you knew.

The moment you find out how something turned out, your memory quietly rewrites what you thought beforehand. You end up certain you saw it coming. That is why almost nobody knows whether their own judgement is any good — the evidence is destroyed by the answer.

Prior Belief seals your reasoning while you still don't know, reopens it months later, and measures the distance between what you expected and what happened.

Seal your first capsule How it works
6,001capsules catalogued
640still sealed right now
57%would decide the same way again

Three things happen here

  1. You write down the real reason. Not the one you'd give at dinner. Plus what you're actually afraid of, and how sure you are as a number. Then it seals.
  2. Months later it opens and asks one question: knowing what you know now, would you decide the same way again?
  3. You get a calibration score — the measured gap between your confidence and your outcomes. Most people discover they are roughly ten points overconfident. Some discover the opposite, which is worse and more useful.

Does confidence predict anything?

Across 5,361 answered capsules, this is how stated confidence lined up with how things actually turned out. A perfectly calibrated archive would climb in a straight line.

They said they wereIt actually worked outCapsules
under 35% sure59% of the time90
35–50% sure67% of the time1,398
50–65% sure67% of the time1,419
65–80% sure67% of the time1,413
over 80% sure67% of the time1,041

The nine questions

Decisions repeat. Yours has been made before, thousands of times, by people who did not know each other.