More Review Questions from Course Material

Instructions: Highlight the correct answer, save as a Word document, and submit this file to the Assignment 1 Dropbox on D2L.

1 . What distinguishes analysis of variance (ANOVA) from t-tests? a. The null hypotheses regarding the equality of means b. The underlying assumption of homogeneity of variances c. The number of groups being compared d. The assumption of random samples from the populations.

2. The basic alternative hypothesis in ANOVA where k = 4 group are being compared is: a. Ha: µ1 = µ2 = µ3 = µ4 b. Ha: µ1 ≠ µ2 ≠ µ3 ≠ µ4 c. Ha: µ1 > µ2 > µ3 > µ4 d. Ha: At least two population means differ

3. In a basic one-way ANOVA, what components are being contrasted? a. Between-group variation to within-group variation b. Between-group variation to total variation c. Between-group variation to treatment variation d. Within-group variance to between-group variation

4. Between-group variation in ANOVA involves differences between ______to the ______. (Fill in the blanks.) a. Individual scores, group means b. Individual scores, grand or overall mean c. Means of one group, means of another group d. Group means, grand or overall mean

5. The formula for the F ratio involves dividing a ______by a ______. (Fill in the blanks.) a. Sum of squares, mean square b. Mean square, sum of squares c. Mean square, mean square d. Mean square, sum of squares

6. If the null hypothesis in a one-way ANOVA situation were true, over the long run the value of F would be: a. Zero b. One c. Depends on degrees of freedom d. Depends on what type of ANOVA it is 7. Two-way ANOVA might be appropriate for which of the following experimental designs? a. Crossover design b. One-group pretest–posttest design c. Two-group before-after design d. Factorial design

8. If a researcher found a significant interaction effect, it would mean that: a. Both of the main effects were also significant b. Neither of the main effects was significant c. The means for different levels of one variable were not consistent across different levels of another d. The means for one variable were different from the means for the second variable

9. If means for a two-way ANOVA were plotted on a graph, an interaction effect might be indicated by: a. Parallel lines b. Curved lines c. Crossed lines d. None of the above Questions 10 through 13 pertain to the following table (Table 7), which presents fictitious results regarding the effects of guided imagery on pain outcomes among patients with cancer.

Table 7

Physiologic Outcomes for Patients with Emphysema during Exercise Performance Under Three Different Conditions (N = 50)

Physiologic Outcome Control With Admin- With F p Condition istration of Compressed Oxygen Air Mean + SD Mean + SD Mean + SD Dyspnea rating (1-10) 4.70± 2.3 4.77 ± 2.6 5.09 ± 2.6 4.99 .008 Heart rate (bpm) 121.1 ± 13.6 126.9 ± 19.9 126.0 ± 21.1 12.54 <.001

Oxygen saturation, SPO2 (%) 91.0 ± 3.9 94.4 ± 4.0 89.9 ± 4.1 9.80 <.001 Breaths per minute 24.1 ± 4.8 24.3 ± 5.9 28.8 ± 6.5 1.86 .22

10. Refer to Table 7. Which statistical test is most likely being reported in this table? a. One-way ANOVA b. Two-way ANOVA c. RM-ANOVA d. It cannot be determined.

11. Refer to Table 7. For which outcome would the researcher need to fail to reject the null hypothesis? a. Dyspnea rating b. Heart rate c. Oxygen saturation d. Breaths per minute

12. Refer to Table 7. What were the degrees of freedom for treatment (df) in these analyses? a. 2 b. 3 c. 47 d. 49

13. Refer to Table 7. Which of the following statements is true, based on information in Table 7? a. Mean dyspnea ratings were significantly higher with compressed air than with O2. b. Interaction effects were statistically significant. c. Mean SPO2 values were significantly higher for the two intervention conditions than for the control condition. d. One or more assumptions for the ANOVA for heart rate was likely violated. 14. The chi-square test is used to test the null hypothesis that: a. The medians of groups being compared are equal b. Two categorical variables are independent (not related) c. The expected cell sizes are zero d. The odds ratio is zero

15. A chi-square test is not appropriate if: a. The distribution of scores is not normal b. The observed frequency in any cell is 0 c. The expected frequency in any cell is 0 d. There are more than five levels of one of the variables

16. For a cell in a crosstab table, the row total is 10, the column total is 20, and the overall sample size is 40. What is the expected frequency for that cell? a. 2 b. 5 c. 20 d. It depends on how many cells there are.

17. Assume a chi-square is computed as follows: χ2 = 1.25 + 1.25 + 2.25 + 2.25 + .50 + .50 = 8.0. What is the dimensionality of the contingency table? a. 2 X 2 b. 2 X 3 c. 3 X 3 d. It cannot be determined.

18. In a 4 X 3 contingency table, how many degrees of freedom would there be for a chi- square test? a. 3 b. 4 c. 6 d. 12

19. In a 2 X 2 contingency table, the magnitude of effects could be communicated by any of the following except: a. Risk difference b. OR c. t-statistic d. RR

20. Which of the following is not a rank-based test? a. Chi-square test b. Kruskal-Wallis test c. Mann-Whitney U test d. Wilcoxon test 21. In the following situation, which test should be used? Independent variable = pretest vs. posttest measurement; dependent variable = stress measured on a 7-point scale. a. Kruskal-Wallis test b. Mann-Whitney U test c. McNemar test d. Wilcoxon signed-rank test