What is the function of a control group in experimental research?

In experimental research, the function of a control group is to provide a baseline against which the effects of the treatment can be compared. This group does not receive the experimental treatment, allowing researchers to isolate the effects of the treatment by contrasting the outcomes between the control group and the treatment group.

By maintaining the control group in a similar environment as the experimental group, researchers can ensure that any differences in results are likely due to the treatment rather than other external factors. This helps to validate the findings of the experiment and supports sound scientific conclusions.

The other options involve activities that do not align with the purpose of a control group. For instance, one option suggests that a group is exposed to the treatment, which describes the treatment group rather than the control group. Another option mentions volunteers, which does not relate to the function of a control group. Lastly, manipulating a group to change variables refers to the experimental group, which is actively involved in testing the hypothesis. Therefore, the role of a control group is uniquely to receive no treatment, ensuring an effective comparison with those that do receive treatment.