NO.PZ2018062016000124
问题如下：
Which of the following descriptions on a two-tailed hypothesis test is least correct?
选项：
A. A two-tailed test is less directive than a one-tailed test.
B. The alternative hypotheses of one-tailed tests has less impacts on the researcher's beliefs than the alternative hypotheses of two-tailed tests.
C. Under the same significance level, the absolute value of two-tailed test's rejection points is larger than the one of one-tailed test.
解释：
B is correct. A two-tailed test is a “not equal to” alternative hypothesis, while a one-tailed test is a “greater than” or “less than” alternative hypothesis. “greater than” or “less than” alternative hypotheses reflect the beliefs of the researcher more strongly than a "not equal to" alternative hypothesis.
为什么双尾的critical point大于单尾