Changing alpha (α) from .05 to .01 ______ the probability of making a type I error and ______ the probability of making a type II error.
A) increases; increases
B) increases; decreases
C) decreases; increases
D) decreases; decreases

Question

Quizplus · Accepted Answer

Decreasing alpha from .05 to .01 decreases the probability of making a type I error (rejecting the null hypothesis when it is actually true) and increases the probability of making a type II error (failing to reject the null hypothesis when it is actually false). This is because as alpha gets smaller, the threshold for rejecting the null hypothesis becomes higher, making it less likely to reject the null hypothesis when it is actually true. However, this also means that it is more difficult to detect a true alternative hypothesis, which increases the risk of failing to reject the null hypothesis when it is actually false.

Changing Alpha (α) from