A t-test found a significant effect in which one condition had a detrimental effect on the outcome, making it significantly worse. In this case, one would expect that Cohen's d would be negative.

Question

Quizplus · Accepted Answer

Cohen's d measures the size of an effect, not its direction; it is concerned with the magnitude of the difference between two means, not whether the effect is positive or negative.

A T-Test Found a Significant Effect in Which One Condition