Group A's mean was a whopping 110, but it was exceeded by Group B's mean of 114. The effect size index in this contest was 0.20. The difference between the two groups should be described as
A) very large
B) large
C) medium
D) small.

Question

Quizplus · Accepted Answer

The effect size index of 0.20 indicates a small difference between the two groups, as effect sizes are generally considered small around 0.2, medium around 0.5, and large around 0.8 or above.

Group A's Mean Was a Whopping 110, but It Was