Homework: Analysis Of Variance
Scenario:
Imagine that a psychologist working with veterans with post-traumatic stress disorder wants to compare the effectiveness of several therapies focused on reducing symptoms of anxiety. The psychologist randomly sampled 20 veterans who recently returned from combat and randomly assigned each of them to receive one of four interventions for 8 weeks. A survey was used to measure the participants' anxiety. Higher anxiety scores indicate more anxiety. You can find the data for this Homework in the Weekly Data Set forum found on the course navigation menu.
To complete this Homework, submit answers to the following. Use SPSS to compare the mean anxiety scores with a one-way ANOVA.
A. Before computing any analyses, state the null hypothesis and alternative hypothesis in words (not formulas).
B. Identify the factor and dependent variable.
C. Name the levels of the factor.
D. State the degrees of freedom between groups and explain how you calculated it by hand.
E. State the degrees of freedom within groups and explain how you calculated it by hand.
F. Identify the obtained F value using SPSS and report it in your answer document.
G. Identify the p value using SPSS and report it in your answer document.
H. Explain whether the F test is statistically significant. Explain how you know.
I. Explain what the psychologist can conclude about the relationship between different types of therapy and anxiety before conducting post hoc tests.
J. Should the psychologist conduct a post hoc test? Why or why not? If post hoc testing is needed, conduct a Tukey HSD post hoc analysis in SPSS. Explain what the results tell you.
Format your homework according to the give formatting requirements:
1. The answer must be double spaced, typed, using Times New Roman font (size 12), with one-inch margins on all sides.
2. The response also includes a cover page containing the title of the homework, the course title, the student's name, and the date. The cover page is not included in the required page length.
3. Also include a reference page. The references and Citations should follow APA format. The reference page is not included in the required page length.