DrBaxter Conducts an Experiment Investigating the Effectiveness of a New

Multiple Choice

Dr.Baxter conducts an experiment investigating the effectiveness of a new antacid on reducing stomach pain.He recruits 100 chronic sufferers of acid indigestion,and places them in four groups,each receiving a different amount of medication.The first group receives a sham pill because it contains none of the new antacid whatsoever.He is very surprised,however,when he finds that group one reports a statistically significant reduction in stomach pain after taking their pill.Which of the following best explains why the participants in group one showed a response to the pill,even when it had no active ingredient?

A) The subject-expectancy effect
B) Demand characteristics
C) The placebo effect
D) The observer-expectancy effect