In a study which compares reaction times between two groups, one which has been asked to run a treadmill for 15 minutes and one not using the treadmill,
-7) effect size is:
A) The size of the difference between the means of the two groups
B) The estimated size of the difference between means of the populations from which the groups are drawn
C) The estimated size of the difference between standard deviations of the populations from which the two groups are drawn
D) The actual size of the mean of the faster group

Question

Quizplus · Accepted Answer

Effect size is the estimated size of the difference between means of the populations from which the groups are drawn. It is a measure of the magnitude of the difference between the two groups, independent of sample size. It is not the actual size of the mean of either group or the difference between standard deviations.

In a Study Which Compares Reaction Times Between Two Groups