| d = M1 - M2 / Ö[(s1²+ s2²) / 2] = D = 7.50 - 2.725 / Ö[(2.038²+ 2.592²) / 2] = 2.05
|
Cohen's d Compute Cohen's d using the two standard deviations. How large is the d using Cohen's
interpretation |
| d = 2t/Ö(df)
= 2(9.16)Ö73.89 = 2.13 |
Cohen's d Compute Cohen's d using the value of the t-test statistic. Are the two values of d similar? |
| g = 2t / ÖN = 2(9.16) / Ö80 = 2.05 |
Hedges's g Compute Hedges's g using the t-test statistic. |
D = M1 - M2 / scontrol = 7.50 - 2.725 / 2.038 = 2.34 |
Glass's delta Calculate Glass's delta using the standard deviation of the control group. |
| rYl = Ö[t²
/ (t² + df)] = Ö[9.16² / (9.16² + 73.89)] = .73 |
Effect size correlation The effect size correlation was computed by SPSS as the correlation between the iv (TREATGRP) and the dv (SUDS4), rYl = . Calculate the effect size correlation using the t value. |
| rYl =
d / Ö(d² + 4) = 2.05 / Ö(2.05² + 4) = .72 |
Effect size correlation Use Cohen's d to calculate the effect size correlation. |