Drag two sliders — how common a thing is, and how accurate the test is — and watch most “positive” results turn out to be false alarms. The rarer the thing, the more a single alarm lies to you.
Interactive — the base-rate machinedrag the sliders
Out of 100 people, 14 test positive — but only 4 are actually sick.
A positive test means you're really sick about 29% of the time.
- sick & flagged
- false alarm
- sick, missed
- healthy