DrNan Is Studying the Effects of Ginseng on Recall

question 111

Multiple Choice

Dr.Nan is studying the effects of Ginseng on recall.He has 2 groups of subjects, (20 subjects in each group) .Subjects are given Ginseng or Placebo and then asked to recall a list of words they previously studied.However,to avoid confounds what should Dr.Nan do?

• A)Counterbalance placebo & Ginseng
• B)Match groups on an IQ test and assign to groups
• C)Randomly assign subjects to groups
• D)All of these
• E)Both b & c