In Testing the Difference Between Two Means, a One-Tailed Test

Multiple Choice

In testing the difference between two means, a one-tailed test would be appropriate when

A) previous experience shows that one condition tends to produce better performance than the other
B) reason clearly suggests that one condition should produce better performance than the other
C) a finding of a difference in the opposite direction would be no different to the experimenter than a finding of no difference at all
D) any of the above conditions exist