taken statistics and social science majors who had not taken statistics with respect to their
responses to an interactive advertising assessment.
Orthodontics and one-way between-groups ANOVA:
Iranian researchers studied factors
affecting patients’ likelihood of wearing orthodontic appliances, noting that orthodontics is
perhaps the area of health care with the highest need for patient cooperation (Behenam & Pooya,
2007). Among their analyses, they compared students in primary school, junior high school, and
high school. The data that follow have almost exactly the same means as they found in their
study, but with far smaller samples. The score for each student is his or her daily hours of
wearing the orthodontic appliance.
Primary school: 16, 13, 18
Junior high school: 8, 13, 14, 12
High school: 20, 15, 16, 18
What is the independent variable? What are its levels?