A researcher working in a sports performance lab was interested in gender and perception of pain during extreme sports and so conducted a t-test. The mean for males was 66.25 and the mean for females was 78.24, with both groups having a standard deviation of 7. What is the effect size using Cohen's d?
A) 1.712
B) 0
C) 1.7
D) -1.712

Question

Quizplus · Accepted Answer

Cohen's d formula involves calculating the difference between the means and dividing by the pooled standard deviation. In this case, the difference between the means is 78.24 - 66.25 = 11.99, and the pooled standard deviation is the square root of [(7^2 + 7^2)/2] = 7. Thus, Cohen's d = 11.99/7 = 1.712. A positive Cohen's d indicates a large effect size favoring females.

A Researcher Working in a Sports Performance Lab Was Interested