What role does a control group play in experimental research?

A control group plays a crucial role in experimental research by serving as a benchmark to measure the effects of the treatment applied to the experimental group. By comparing outcomes between the control group and the experimental group, researchers can isolate the impact of the treatment and determine whether any observed changes in the experimental group are indeed due to the treatment rather than other factors.

The control group is not exposed to the treatment being tested, which allows researchers to account for external variables and biases that could affect the results. This comparative analysis enhances the validity of the findings, as it provides a clear reference point against which to measure the effectiveness of the intervention.

The remaining options do not accurately describe the function of a control group. While the experimental treatment is administered to the experimental group, the control group receives no such treatment, which differentiates its role. Conducting interviews does not relate to the fundamental purpose of a control group, and increasing the size of the study population is typically addressed through recruitment strategies rather than through the establishment of a control group.