Experimental subjects are given a pill to test its effectiveness on reducing the duration of a cold. How should the control group be treated?
A) Do nothing with the control group.
B) Give the control group two pills instead of one.
C) Give the control group a pill that does not affect the duration of colds.
D) Let the control group choose whether or not to take any pills.

Question

Quizplus · Accepted Answer

The best choice is to give the control group a pill that does not affect the duration of colds. This ensures that any changes in the experimental group are due to the experimental pill and not other factors. Doing nothing with the control group (A) does not control for potential placebo effects or other factors that may influence the duration of colds. Giving the control group two pills (B) would make it difficult to distinguish whether any observed effects are due to the experimental pill or simply a higher dose of the control pill. Letting the control group choose whether or not to take any pills (D) would not be a controlled experiment and does not ensure that the groups are truly comparable.

Experimental Subjects Are Given a Pill to Test Its Effectiveness