Researchers have developed an new drug to treat a specific illness. They believe that it will help patients with the illness to recover faster if they take the drug. They select 100 patients to test the drug and divide them into two groups. Group 1 contains 50 patients (25 male and 25 female) who are given a pill that contains the new drug. Group 2 contains 50 patients (25 males and 25 females) who are given a placebo pill (a pill that does not contain the new drug). The pills look exactly the same. Patients are not aware of the group to which they have been assigned. All of the patients take their pill twice a day (once in the morning and once in the evening). The medical staff monitor the patients and how long it takes for them to recover. How long it takes the patients to recover is a ______________. Constant Control Dependent Independent