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

The role of a control group in an experiment is to serve as a standard for comparison against the experimental group. By maintaining a control group that does not receive the experimental treatment or is not exposed to the variable being tested, researchers can observe and measure the effects of the treatment in the experimental group more accurately. This comparison helps to determine whether any observed changes in the experimental group can be attributed to the treatment itself or if they might be due to other factors. Essentially, the control group provides a baseline that strengthens the validity of the experimental results, enhancing the ability to make conclusions about the specific impact of the experimental variable.