题目
Which of the following statements are NOT true? I.Type I error occurs when the null hypothesis is not rejected when it is actually false. II.Type II error occurs when the null hypothesis is rejected when it is actually true. III.Type I error occurs when the alternate hypothesis is wrongly accepted. IV.Minimizing the probability of Type II error maximizes the power of the test.
选项
A.I and II
B.I and III
C.II and IV
D.I, II and IV
答案
A
解析
In hypothesis testing we accept the alternate hypothesis if the null hypothesis has been rejected. Type I error happens if the null hypothesis is rejected when it is actually true. Type II error happens if the null hypothesis is accepted when it is actually false. The power of the test is the probability of correctly rejecting the null hypothesis (when it is false), so minimizing Type II errors would maximize the power of the test. 在假设检验中，如果原假设被拒绝，我们接受替代假设。如果在原假设为真时拒绝原假设，则会发生I类错误。如果在原假设为假的情况下接受原假设，则会发生II类错误。测试的功效是正确拒绝零假设（当它为假时）的可能性，因此，将II类错误最小化将使检验的功效最大化。