[2] In Bayesian analysis, the base rate is combined with the observed data to update our belief about the probability of the characteristic or trait of interest.
The updated probability would be a combination of the base rate and the likelihood of the test result given the disease status.
[5] Mathematician Keith Devlin illustrates the risks as a hypothetical type of cancer that afflicts 1% of all people.
The doctor should be asked, "Out of the number of people who test positive (base rate group), how many have cancer?
"[6] In assessing the probability that a given individual is a member of a particular class, information other than the base rate needs to be accounted for, especially featural evidence.