Question

An independent-measures research study with n = 5 participants in each treatment produces sample variances of 8 and 10, and a 2-point difference between the two treatment means. given this information, what is the value of cohen's d? 2/2 2/3 2/9 2/18

Answer 1

Cohen's d is given by:


`Cohen's\ d= \frac{mean\ difference}{ \sqrt{ ((n_1-1)s_1^2+(n_2-1)s_2^2)/(n_1+n_2-2) } } \\ \\ = \frac{2}{\sqrt{((5-1)8+(5-1)10)/(5+5-2)}} = \frac{2}{ \sqrt{ (32+40)/(8) } } = (2)/( √(9) ) \\ \\ =(2)/(3)`