7. Effect size - Cohen's d and r squared An industrial/organizational psychologist has been consulting with a company that runs weekend job-seeking workshops for the unemployed. She collected data on several issues related to these workshops and, after conducting statistical tests, obtained statistically significant findings. She needs to find a way to evaluate effect size so that she can make recommendations to the company. One of the psychologist's findings is that six months after the workshop, a sample of 81 job seekers who received training on setting career goals worked more than 30 hours per week an average of 8.7 months in the last year, with a standard deviation of 4.1. The typical job seeker works 7.4 months. The psychologist finds that the estimated Cohen's d is the t statistic is 2.83, and r² is treatment effect. Using Cohen's d and Cohen's guidelines for interpreting the effect size with the estimated Cohen's d, there is a Using r² and the extension of Cohen's guidelines for interpreting the effect size using r², there is a treatment effect. (Hint: When using Cohen's guidelines for interpreting the effect size, if the value lies between two categories, then specify the range covered by both categories, for example, medium to large.) Another one of the psychologist's findings is that a sample of 81 job seekers who received training on identifying marketable skills scored an average of 8.1 as measured on a 9-point job search motivation scale, with a standard deviation of 0.8. The typical job seeker scores 7.4 points. She finds that the estimated Cohen's d is interpreting the effect size with the estimated Cohen's d, there is a , the t statistic is 7.78, and r² is . Using Cohen's d and Cohen's guidelines for treatment effect. Using r² and the extension of Cohen's guidelines for