What is the purpose of a control group in an experiment?

The purpose of a control group in an experiment is to serve as a baseline for comparison against the treatment group. In experimental research, researchers often manipulate one variable (the independent variable) to observe its effect on another variable (the dependent variable). The control group does not receive the experimental treatment, allowing researchers to isolate the effects of the treatment by comparing outcomes between this group and the treatment group.

By having a control group, researchers can better determine whether observed changes in the experimental group are due to the treatment itself or other factors. This comparison is crucial for establishing the validity and reliability of the study's results, enabling clearer insights into the effectiveness of the intervention being tested.