Use of a one-tailed versus a two-tailed t test to test the significance of the difference between two sample means depends on whether
A) there is expected overlap between the error curves of the two sample distributions.
B) the difference is expected to be in one direction only.
C) the size of the samples is proportional to their respective population sizes.
D) research participants were matched or chosen randomly.

Question

Quizplus · Accepted Answer

A one-tailed t-test is used when the difference is expected to be in one direction only, allowing for testing a specific hypothesis about the direction of the difference between two sample means.

Use of a One-Tailed Versus a Two-Tailed T Test to Test