A primary study evaluated the effectiveness of a therapy designed to treat graduate students suffering from clown phobia. On the dependent measure of attraction toward clowns, the mean score for the treatment group is 5, whereas the mean score for the control group is 4. The pooled standard deviation is 2. Cohen's d is:
A) 5
B) 4
C) 2
D) 0.5

Question

Quizplus · Accepted Answer

Cohen's d is calculated by subtracting the mean score of the control group from the mean score of the treatment group and dividing the result by the pooled standard deviation. In this case, (5-4)/2=0.5, so the answer is D.

A Primary Study Evaluated the Effectiveness of a Therapy Designed