What is the purpose of "control groups" in experimental research?

The purpose of control groups in experimental research is to serve as a benchmark for comparison. Control groups are vital as they allow researchers to gauge the effectiveness of the intervention being tested against a group that does not receive that intervention. By comparing outcomes between the experimental group (which receives the intervention) and the control group, researchers can determine whether changes in the experimental group can be attributed to the intervention rather than other factors. This comparison helps establish a cause-and-effect relationship and strengthens the validity of the study results.

In experimental research, having a control group helps to control for extraneous variables that could influence outcomes, enabling a clearer understanding of the actual impact of the intervention. This is essential for ensuring that the findings are not due to confounding variables, thereby enhancing the reliability of the conclusions drawn from the study.