Statistics Exercise IV: Analysis of Variance
These weekly exercises provide the opportunity for you to understand and apply statistical methods and analysis. Unless otherwise stated, use 5% (.05) as your alpha level (cutoff for statistical significance).
#1. Which type of ANOVA would you use for each of the studies below?
- One-way between subjects (independent groups)
- One-way within subjects (repeated measures)
- Two-way between subjects
- Measure the self-esteem of the same group of college students at the beginning, middle and end of their freshman year.
- Compare math skills for three different professional groups: physicians, attorneys and psychologists.
- Measure Body Mass Index (BMI) for persons who take Supplement X vs. a placebo and who either exercise regularly or don’t. So there are four groups: 1) Exercise/Take Supplement X, 2) Don’t Exercise/Take Supplement X, 3) Exercise/Take Placebo, 4) Don’t Exercise/Take Placebo
- Look at satisfaction with mental health services based on the client’s ethnicity (White, Black, Hispanic, Asian or Other) and how they were greeted on their initial visit (receptionist smiles or does not smile).
Use SPSS and the data file found in syllabus resources (DATA540.SAV) to answer the following questions. Round your answers to the nearest dollar, percentage point, or whole number.
#2. Perform a one-way ANOVA to look at whether income (INC1) differs by type of relationship (RELAT). Which of the following describes your result:
A. F(3,396) = 4.91, p > .05
B. F(3,396) = 4.91, p < .001
C. F(3,396) = 6.85, p > .05
D. F(3,396) = 6.85, p < .001
Perform a 2-way ANOVA with participant’s income (INC1) as the dependent variable and with gender (GENDER1) and marital status (MSTAT) as independent variables. Interpret your results in questions 6, 7 and 8. (Hint: click the “Plots” button in the Univariate routine to create a graph).
#3. The main effect due to gender indicates that:
A. Women earn more than men.
B. Men earn more than women.
C. Men and women have incomes that are not significantly different.
D. Participants earn more than their partners.
#4. The main effect due to marital status indicates:
A. Your income tends to decrease after a divorce.
B. Getting married tends to increase your income.
C. Marital status is unrelated to income.
D. Married people tend to earn more than single people.
#5. The interaction effect indicates:
A. Men earn more than women and married people earn more than singles.
B. The male/female income difference is greater when comparing married people than when comparing singles.
C. The interaction effect is non-significant.
D. Marriage helps men’s careers more than it helps women’s careers.