If I was conducting a study on the effect of a new anti-depressant drug (compared to a placebo drug) on depression scores, which one of the following would be a suitable one-tailed hypothesis?
A) There will be an effect of drug type on depression scores.
B) Drug type and depression scores will be related.
C) Those who are given the new drug will show lower levels of depression in comparison to those given the placebo.
D) There will be no effect of drug type on depression scores.

Question

Quizplus · Accepted Answer

A one-tailed hypothesis predicts the direction of the effect. Choice C specifically predicts that the new drug will lower depression scores compared to the placebo, which is a directional hypothesis suitable for a one-tailed test.

If I Was Conducting a Study on the Effect of a New