An end-point of a critical region. In a hypothesis test, comparison of the value of a test statistic with the appropriate critical value determines the result of the test. For example, 1.96 is the critical value for a two-tailed test in the case of a normal distribution and a 5% significance level: thus if the test statistic z is such that ǀzǀ>1.96 then the alternative hypothesis is accepted in preference to the null hypothesis.