A statistical test is a procedure used to decide if an assertion (often called a hypothesis) about a population’s chosen quantitative feature is true or false. These tests usually entail drawing on a random sample (or simple random sample) from the chosen population, then calculating a statistic about the chosen feature. From the result, a statistician can usually determine if the hypothesis is true, false, rare, common, or something in between. Overall, for a statistical test to be valid, it is necessary to choose what statistic to use, what sample size, and what criteria to use for rejection or acceptance of the tested hypothesis.