A researcher is interested in whether massed or spaced studying has a greater impact on grades in a course. The researcher has her class study for 6 hours all in one day for one exam (massed study condition). She has them study for 2 hours each day for 3 days for another exam (3-day spaced condition). Last, she has them study for 1 hour a day for 6 days for a third exam (6-day spaced condition). The mean exam score (out of a possible 100 points) for each condition appears next, along with the ANOVA summary table.

a. Complete the ANOVA summary table.

b. Is F_obt significant at α = .05; at α = .01?

c. Perform post hoc comparisons if necessary.

d. What conclusions can be drawn from the F-ratio and the post hoc comparisons?

e. What is the effect size, and what does this mean?

f. Graph the means.

df Source MS Subject Between 136.96 3,350.96 499.03 Error Total 3,986.95 Study Condition Massed Mean 69.13 15 3-day spaced 6-day spaced 79.33 15 90.27 15