Question

For an independent-measures research study (i.e., independent measures t Test), the data show an 8-point difference between the two treatment means and a pooled variance of 16. Given this information, what is the value of Cohen’s d?

A. 5
B. 3
C. 2
D. Cannot answer without knowing the sample sites

Answer 1

C. 2

Explanation:

Cohen's d is a parameter used to express the standardised difference between two means. It is defined as the difference between the means divided by the pooled standard deviation.

In this case, the difference between both means (M2-M1) is 8. As for the pooled standard deviation, simply take the square root of the given pooled variance:

`S=√(S^2)\\S=√(16) \\S= 4`

Therefore, the value of Cohen's d (d) is:

`d=(M_(2) -M_(1))/(S) \\d=(8)/(4)\\d=2`