A group that is given a placebo in a research study. A placebo is something that does not directly affect the behavior or symptoms under study in any specific way. A researcher must be able to separate placebo effects from the actual effects of the intervention being studied. For example, in a drug study, subjects in the experimental and placebo groups may receive identical-looking medication, but those in the experimental group are receiving the study drug while those in the placebo group are receiving a sugar pill. Typically, subjects are not aware whether they are receiving the study drug or a placebo.