Basic Hypothesis Testing Terminology Worksheet Choose the correct terminology for each of the below definitions from the following lists of terms: hypothesis, hypothesis testing, rare event rule for inferential statistics, null hypothesis, alternative hypothesis, test statistic, critical region, critical value, significance level, two-tailed test, right-tailed test, left-tailed test, traditional method, type I error, and type II error. A procedure for testing a claim about a property of a population. Terminology: Hypothesis test The critical region is in the extreme right region (tail) under the curve. Terminology: Right-tailed test The set of all values of the test statistic that cause us to reject the null hypothesis. Terminology: Critical region A value used in making a decision about the null hypothesis. It is found by converting the sample statistic (such as proportion 𝑝̂ , the sample mean 𝑥̅ , or the sample standard deviations) to a score (such as z, t, or χ2) with the assumption that the null hypothesis is true. Terminology: Test Statistic If the test statistic falls within the critical region, reject H0. If the test statistic does not fall within the critical region, fail to reject H0. Terminology: Traditional method The critical region is in the two extreme regions (tails) under the curve. Terminology: Two-tailed test The mistake of rejecting the null hypothesis when it is actually true. Terminology: Type I error A claim or statement about a property of a population. Terminology: Hypothesis The probability that the test statistic will fall in the critical region when the null hypothesis is actually true. If the test statistic falls in the critical region, we reject the null hypothesis, so α is the probability of making a mistake of rejecting the null hypothesis when it is true. The mistake of failing to reject the null hypothesis when it is actually false. Terminology: Type II error The critical region is in the extreme left region (tail) under the curve. Terminology: Left-tailed test A statement that the parameter has a value that differs somewhat from the null hypothesis. Terminology: Alternative hypothesis Any value that separates the critical region (where we reject the null hypothesis) from the values of the test statistic that do not lead to rejection of the null hypothesis. The critical values depend on the nature of the null hypothesis, the sampling distribution that applies, and the significance level of α. Terminology: Terminology: Significance level Critical value A statement that the value of a population If, under a given assumption, the probability of a parameter (such as proportion, mean, or particular observed event is extremely small, we standard deviation) is equal to some claimed conclude that the assumption is probably not value. It is assumed to be true and a conclusion correct. is reached to either reject or fail to reject it. Terminology: Terminology: Null hypothesis Rare event rule for inferential statistics