A researcher conducts a t test for dependent means in which it is predicted that there will be a decrease in unemployment from before to after a particular job-skills training program. The cutoff "t" needed is -1.8333. The standard deviation of the distribution of means of change scores is 2.0 and the mean change score for the sample studied is an increase of 5.2.
What is the effect size?
5.2/-1.833 = -2.84; large
2/5.2 = .38; approximately medium
5.2/2 = 2.60; large
It can not be determined without also knowing the population standard deviation
Check out the third choice.
To calculate the effect size for a t test for dependent means, you will need to divide the mean change score by the standard deviation of the distribution of means of change scores.
In this case, the mean change score is an increase of 5.2 and the standard deviation is 2.0.
Therefore, the effect size is calculated as:
5.2 / 2.0 = 2.6
The effect size is 2.6, which can be classified as large.
To calculate the effect size in this case, we need to use the formula d = M/SD, where M represents the mean change score and SD represents the standard deviation of the distribution of means of change scores.
Given that the mean change score (M) is an increase of 5.2 and the standard deviation (SD) is 2.0, we can calculate the effect size:
d = 5.2 / 2.0 = 2.60
Therefore, the effect size in this case is 2.60, which is considered large.
To determine the effect size, we divide the mean change score by the standard deviation. A larger effect size indicates a stronger relationship or a larger difference between the groups being compared. In this case, a larger effect size of 2.60 suggests a substantial decrease in unemployment after the job-skills training program.