Introductory Psychology CLEP Prep Practice Exam

A control group is used to provide a baseline comparison for the experimental group. This helps to minimize the impact of external variables and determine if any changes observed in the experimental group are truly due to the intervention or just coincidental. The other choices are incorrect because B refers to a potential method for reducing bias, C is referring to the objective of a study rather than the role of a control group, and D refers to the overall validation of a study rather than the specific purpose of a control group.