What statistical test did the researchers use to determine if there was a statistically significant difference in levels of self-esteem between the boys and the girls?
What was the purpose of calculating a Cohen's d? When is a Cohen's d calculated? Interpret d=.90. What does it mean in this example?
What if the researcher compared the adolescent boys before treatment and again after treating them for depression? What type of t-test would be most appropriate in this case, and why?