PSYCHOLOGY 30L Problem Set #3: One-Way ANOVA and Analytical Comparisons Name: Score:. You and Dr. Exercise have decided to conduct a study on exercise and its effects on mood ratings. Many studies (Babyak et al., 000; Blumenthal et al., 999) have suggested that exercise does indeed improve overall mood ratings. In addition, exercise has been shown to reduce scores on the Beck Depression Inventory II (BDI-II). Below are the scores from a mood rating scale for 8 females. Participants were randomly assigned to of 3 exercise conditions: 30 minutes, 60 minutes and 90 minutes. Participants participated in the exercise three times a week for a period of six months. After the conclusion of the exercise program, participants were instructed to rate their mood. The higher the score, the more evidence there is for depression. 90 Minutes 60 Minutes 30 Minutes 4 7 3 3 8 5 9 3 7 7 4 9 3 5 8 3 9 5 9 4 6 5 7 B. Do a planned comparison to determine whether exercising 90 minutes leads to less depression than exercising 30 minutes using α =.05. Be sure to state your hypotheses, state the decision rule, calculate the F ratio for the C. Do a planned comparison to determine whether exercising 90 minutes leads to less depression than other amounts of exercise using α =.05. Be sure to state your hypotheses, state the decision rule, calculate the F ratio for the D. Measure the size of the treatment effect using estimated omega-squared and R. Describe what E. Calculate a confidence interval for the population mean for depression scores when exercising 90 minutes. State in words what this confidence interval means.
. Descriptive Statistics Group n Mean Standard Deviation Interval-- Lower Bound Interval Upper Bound Test of Homogeneity of Variance Levene Statistic df df Significance ANOVA TABLE Source SS df MS F Significance Between-Group Within-Group Total Coefficients Tests Assume Equal Variances Value of Standard Error t df Sig.
. Eysenck (95) and others have frequently asked if the type of therapeutic intervention has an effect on counseling outcomes. Below are scores on an anxiety scale for 8 neurotics after 6 weeks of therapy; the higher the score, the greater the anxiety. Psychoanalysis Behavior Modification Client-Centered No Therapy 9 8 6 5 8 9 4 7 3 0 8 6 5 7 5 3 5 4 4 5 6 8 9 3 B. Do a planned comparison to determine whether psychoanalysis results in less anxiety than behavior modification therapy using α =.05. Be sure to state your hypotheses, state the decision rule, calculate the F ratio for the C. Do a planned comparison to determine whether no therapy results in less anxiety than therapy using α =.05. Be sure to state your hypotheses, state the decision rule, calculate the F ratio for the D. Measure the size of the treatment effect using estimated omega-squared and R. Describe what E. Calculate a confidence interval for the population mean of anxiety levels in the no therapy condition. State in words what this confidence interval means.. Descriptive Statistics Group n Mean Standard Deviation Interval-- Lower Bound Interval Upper Bound
Test of Homogeneity of Variance Levene Statistic df df Significance ANOVA TABLE Source SS df MS F Significance Between-Group Within-Group Total Coefficients Tests Assume Equal Variances Value of Standard Error t df Sig.
Problems for Further Practice. Using the following data derived from the ten-year period 955 to 964, determine whether there is a significant difference in death rate among the various seasons. (Note: Assume death rates for any given year to be independent.) Winter Spring Summer Fall 0.0 9.5 8.5 9.5 0. 9.7 8.4 9.4 0.0 9.6 8.8 0. 0.4 9. 8.6 9.8 0. 9.4 8.7 9.4 0.5 9. 8.3 9.6 9.9 9. 8.4 9.5 0. 8.9 8.5 9.7 0.7 9.5 8.9 9.3 0. 9.3 8.3 9.4 B. Do a planned comparison to determine whether summer has a lower death rate than winter using α =.0. Be sure to state your hypotheses, state the decision rule, calculate the F ratio for the C. Do a planned comparison to determine whether summer has a lower death rate than the other seasons combined using α =.0. Be sure to state your hypotheses, state the decision rule, calculate the F ratio for the D. Measure the size of the treatment effect using estimated omega-squared and R. Describe what E. Calculate a confidence interval for the population mean of summer death rates. State in words what this confidence interval means.
. Before making a decision about an advertising brochure, a publisher ran an experiment to discover whether the responses by readers to certain ads differed. More specifically, he wanted to test responses to three kinds of ads: ads with a color picture, ads with a black and white picture, and ads with no picture. Each ad was inserted in a magazine with other printed material intended to draw attention away from the material being evaluated. Subjects rated the critical ad on an point scale where the higher the number, the greater the preference for the ad. Results for the subjects are as follows: Color Black & White No Picture 3 4 0 3 7 7 7 5 8 6 3 5 8 9 9 8 7 5 7 6 B. Do a planned comparison to determine whether color or black and white photographs are preferred using α =.05. Be sure to state your hypotheses, state the decision rule, calculate the F ratio for the C. Do a planned comparison to determine whether all pictures are preferred over no pictures using α =.05. Be sure to state your hypotheses, state the decision rule, calculate the F ratio for the D. Measure the size of the treatment effect using estimated omega-squared and R. Describe what E. Calculate a confidence interval for the population mean of color picture preference ratings. State in words what this confidence interval means.