A standard verbal memory test is known to have a standard deviation of 10 points. If an experimental procedure produced an increase of 8 points, the effect size would represent a __________ effect size.
A)small
B)medium
C)large
D)unable to determine without additional information

Question

Quizplus · Accepted Answer

The effect size is calculated as the mean difference (in this case, 8 points) divided by the standard deviation (10 points), giving an effect size of 0.8. According to Cohen's conventions for interpreting effect sizes, 0.8 is considered a large effect size.

A Standard Verbal Memory Test Is Known to Have a Standard