Power
MCAT glossary · Critical Analysis & Reasoning Skills
Definition
In statistics, the probability 1 - β of correctly rejecting a false null hypothesis.
Power in plain English
Power is a study's ability to actually catch a real effect when one truly exists — like a metal detector that reliably beeps when there's real treasure buried. In stats you start assuming 'nothing's going on' (the null hypothesis); power is the probability you'll correctly reject that when it's genuinely false. It equals 1 - β, where β is the chance of a 'false alarm in reverse' — missing a real effect. Bigger sample sizes usually mean more power, which is why weak studies can fail to notice things that are truly there.
Learn these first
Sign up free: all 171 MCAT terms as flashcards, plus practice questions with full explanations →
Related MCAT terms
MCAT practice questions · MCAT flashcards · MCAT study guide