Consider the same setting as that of Exercise 4.39. Of the 100 participants, 45 are male and 55 are female. During the design of the study, one member of the research team suggests that all males be given the active drug and all females be given the placebo. Another member of the team wants to randomly assign each of the total group of 100 participants to one of the two treatments.
a. Which researcher’s plan is the best experimental design for measuring the effectiveness of the medication if the results of the experiment are to be generalized to the entire population, which consists of both females and males?
b. Does the fact that the participants of the study were recruited rather than selected at random prohibit generalization of the results?