Using a two-tailed test makes it __________ to get significance on any one tail. Thus, keeping everything else the same, power __________ with a two-tailed test than with a one-tailed test.
A)easier; more
B)harder; less
C)easier; less
D)harder; more

Question

Quizplus · Accepted Answer

Using a two-tailed test makes it harder to achieve significance on either tail because the significance level (alpha) is split between the two tails. Consequently, the power, which is the probability of correctly rejecting a false null hypothesis, is less with a two-tailed test than with a one-tailed test, assuming all other factors are constant. This is because a larger effect size is needed to achieve significance when the alpha is divided.

Using a Two-Tailed Test Makes It __________ to Get Significance