Consider the following hypothetical results, as published in a hypothetical journal: “The participants had been divided equally among three experimental conditions negative feedback, positive feedback, and no feedback —and the mean scores for the three groups at the end of the study were 11.1, 14.7, and 12.4, respectively. Moreover, the group differences were found to be statistically significant, F (2, 57) = 3.69, p < .05.”

(a) Find the value of η² for these data. How would you describe the size of this effect?

(b) Estimate ω² for the population represented by these groups.