Problem
Blocking is used to control the effects of lurking variables on the response to the treatment. How might we control the effects that the environment in which the ads are viewed have on the response to the treatment?
A study is conducted to determine the effectiveness of Drug A versus Drug B in relieving migraine headaches in women. 120 women who suffer from migraines were randomly selected for the study.
A. Use a diagram to outline the experiment using a completely randomized design that incorporates a placebo.
B. Explain what is mean by the placebo effect in regards to this experiment and discuss how giving a placebo to a control group addresses this problem.
C. Can this experiment be made to be double-blind? If so how?