Base Rate Fallacy Identification Quiz

This quiz will help you discover if your thinking is affected by the base rate fallacy, a cognitive bias where people tend to ignore base rate information.

Question 1 of 7Version: 1.0

A rare disease affects 1 in 1,000 people. There is a test for this disease that is 99% accurate. If a person tests positive, what is the likelihood they actually have the disease?

About 99%

About 50%

Less than 10%

It depends on the person's medical history.