A one-tailed test of significance could be used whenever
A)the researcher can predict a direction for the difference.
B)the researcher feels like it.
C)the null hypothesis is thought to be true.
D)the alpha level exceeds 0.10.

Question

Quizplus · Accepted Answer

A one-tailed test is used when the researcher has a directional hypothesis, i.e., predicts a specific direction of the difference between groups or conditions. Therefore, choice A is the correct answer. Choice B is incorrect because conducting a test of significance based on personal feelings or preference is not appropriate. Choice C is incorrect as a result of the null hypothesis being assumed to be true in every hypothesis test until proven otherwise. Choice D is incorrect because an alpha level exceeding 0.10 means that the significance level is overly lenient and higher than what is typically used in hypothesis testing, which increases the probability of making a type I error.

A One-Tailed Test of Significance Could Be Used Whenever