n. an error in prediction and decision-making which occurs when base rate is ignored as a prior probability. As such, the factor of base rate is not given enough weight, and false conclusions may be drawn from information simply based on a particular trait and its rate of occurrence in a specific population.

BASE-RATE FALLACY: "If you overlook the base-rate information that 90% and then 10% of a population consist of lawyers and engineers, respectively, you would form the base-rate fallacy that someone who enjoys physics in school would probably be categorized as an engineer rather than a lawyer. "
Cite this page: Nugent, Pam M.S., "BASE-RATE FALLACY," in, April 7, 2013, (accessed February 19, 2018).