A family science professor wants to study the impact of frequent quizzes on her students’ study habits. In one of her classes she does not offer quizzes. In another class, she offers a quiz once per week. In her last class she offers a quiz in every class session. In each class she asks her students how many hours per week they studied.

a. What is the independent variable in this example?

b. What is the dependent variable in this example?

c. How did the professor operationalize “study habits”?

d. Is this an experimental design or a correlation design?