Dr.Wilkins randomly assigns subjects to one of two groups.He is interested in the effects of caffeine on anxiety levels.He gives subjects in the first group an extra two cups of coffee a day for six months.The second group receives an extra two cups of decaffeinated coffee a day for the same time period.Importantly,subjects do not know whether they are being given regular or decaffeinated coffee.By providing one group with decaffeinated coffee,Dr.Wilkins is trying to account for which potential element of the experiment?
A)the Hawthorne effect
B)generalizability
C)the placebo effect
D)variability

Question

Quizplus · Accepted Answer

By providing one group with decaffeinated coffee, Dr. Wilkins is trying to account for the placebo effect. The placebo effect is the phenomenon in which people's belief or expectation about a treatment (in this case, the caffeine in the coffee) influences the outcome, even if the treatment itself has no physiological effect. By giving one group decaffeinated coffee (which looks and tastes the same), the subjects will be less likely to expect or believe that they are receiving caffeine, which could otherwise influence their anxiety levels.

DrWilkins Randomly Assigns Subjects to One of Two Groups