Calculating Analysis of Variance (ANOVA) and Post Hoc Analyses Following ANOVA
- Do the data meet criteria for homogeneity of variance? Provide a rationale for your answer.
- If calculating by hand, draw the frequency distribution of the dependent variable, hours worked. What is the shape of the distribution? If using SPSS, what is the result of the Shapiro-Wilk test of normality for the dependent variable?
- What are the means for three groups’ hours worked on a job?
- What are the F value and the group and error df for this set of data?
- Is the F significant at α = 0.05? Specify how you arrived at your answer.
- If using SPSS, what is the exact likelihood of obtaining an F value at least as extreme as or as close to the one that was actually observed, assuming that the null hypothesis is true?
- Which group worked the most weekly job hours post-treatment? Proved a rationale for your answer.
- Write your interpretation of the results as you would in an APA-formatted journal.
- Is there a difference in your final interpretation when comparing the results of the LSD post hoc test versus Tukey HSD test?
- If the researcher decided to combine the two Treatment as Usual groups to represent an overall “Control” group, then there would be two groups to compare: Supported Employment versus Control. What would be the appropriate statistic to address the difference in hours worked between the two groups?