1. Researchers recruited over 1,000 patients with chronic back pain to participate in a study about the benefits of acupuncture. Each subject was randomly assigned to one of these treatment
plans: traditional Chinese acupuncture, placebo acupuncture, and conventional pain treatment of
medication and physical therapy.
What is the primary purpose of randomly assigning subjects to the different treatment plans?
(2 Points)
To increase confounding variables
To create groups that are as similar as possible so the main difference between the groups is the
treatments
To control against nonresponse
To ensure both the subjects and researchers are blind to who is in which group
To reduce the impact of sampling variability