 As stated above, our measure of effect size will be the Pearson Product Moment correlation coefficient r. For this study we chose an effect size of r .50 as the smallest effect size that would be clinically meaningful, and then calculated that we would need a sample size of 26, to obtain power of 81, and a 95.0 confidence interval r .13 to r .75 that would not include zero. Rosenthal, 1991. 