Discuss the following:
ANOVA (One-Way Analysis of Variance)
1. A psychologist would like to investigate the relative effectiveness of three therapeutic techniques for treating mild phobias. A sample of 15 individuals who demonstrate a moderate fear of spiders are randomly assigned to each of the three therapies. The data given below represent a measure of reported fear of spiders after therapy (higher numbers imply more fear). Do the different therapies produce different results? Test at = 0.05.
Therapy A: 5 6 3 4 3
Therapy B: 3 3 0 2 2
Therapy C: 1 0 1 2 1
a. The name of this test is:
b. List 2 assumptions or special notes:
c. Hypothesis:
d. F-test value:
e. P-value:
f. Conclusions: Reject or Retain H0 (circle one)
Summary Statement:
g. If one of the therapies is better than the others, which is it and why?
2. A researcher wishes to investigate if 3 different techniques lower a person's systolic blood pressure (SBP). Subjects are randomly assigned to three groups: medication, exercise, and diet, and after four weeks, the reduction in each person's SBP is recorded (and given below). Test the claim at = 0.05.
Medication: 10 12 9 15 13 8 8
Exercise: 6 8 3 0 2 4 4
Diet: 5 9 7 8 4 8 3
a. The name of this test is:
b. List 2 assumptions or special notes:
c. Hypothesis:
d. F-test value
e. P-value:
f. Conclusions: → Reject or Retain H0 (circle one)
→ Summary Statement:
g. Which (if any) technique appears most effective in lowering SBP, and why?
h. Summarize the Homogeneity of Variance test:
-- Hypothesis:
H0: H1:
-- Test Statistic:-- P-value:
-- Conclusion: Reject or Retain H0 (circle one)
Summary Statement
j. Summarize the results of a Tukey Post Hoc test:
k. Calculate the effect size:
η2