How can we reduce the rate of refusals in telephone surveys? Most people who answer at all listen to the interviewer’s introductory remarks and then decide whether to continue. One study made telephone calls to randomly selected households to ask opinions about the next election. In some calls, the interviewer gave her name; in others, she identified the university she was representing; and in still others, she identified both herself and the university. For each type of call, the interviewer either did or did not offer to send a copy of the final survey results to the person interviewed.

a. List the factors in this experiment and state how many levels each factor has.

b. If the researchers used every possible combination to form the treatments, how many treatments were included in the experiment?

c. List two of the treatments.