A researcher is interested in studying changes in marital satisfaction over the course of marriage. She hypothesizes that marital satisfaction is highest when couples are newly married, that it decreases during the middle years of marriage, but rises again during later years of marriage. In order to test her hypothesis, she recruits fifty married couples within each of the following conditions: (1) married less than 10 years; (2) married 15-20 years; (3) married more than 25 years. All 150 couples (50 from each condition) complete a standardized measure of marital satisfaction.
What assumptions would the researcher have to make to analyze these data correctly?
A) Homogeneity of variance across groups
B) Normality of the satisfaction scores within each group.
C) Independence of observations
D) All of the above.

Question

Quizplus · Accepted Answer

The researcher would have to assume that there is homogeneity of variance across the three groups, that the satisfaction scores within each group are normally distributed, and that the observations are independent. Therefore, all of the above assumptions would need to be made to analyze the data correctly.

A Researcher Is Interested in Studying Changes in Marital Satisfaction