Which group is not exposed to the treatment and serves as a baseline for comparison?

• A. Control group
• B. Placebo group
• C. Baseline measure
• D. Debriefing

Answer: (A)

The main idea here is understanding the role of a group that provides a baseline for comparison by not receiving the treatment. In experiments, you compare outcomes between those who receive the intervention and those who do not, so you can attribute any differences to the treatment itself. The group that is not exposed to the treatment serves as this reference point, staying untreated (or receiving standard care) to show what would happen without the manipulation. A placebo group, while similar, still receives something inert to mimic the treatment and control for expectancy effects, so it isn’t truly unexposed. A baseline measure is a pre-treatment score, not a separate group, and debriefing occurs after the study. Thus, the untreated group used for comparison is the control group.