what is a control group

A control group is a group of participants in an experiment who do not receive any experimental treatment. The control group serves as a comparison group to the experimental group, which receives the treatment being tested. It is important that every aspect of the experimental environment is the same for both groups, and that the experimenters carry out the exact same procedures with both groups so that researchers can confidently conclude that any differences between groups are actually due to the difference in treatments. The control group is important because it serves as a baseline, enabling researchers to see what impact changes to the independent variable produce and strengthening researchers’ ability to draw conclusions from a study. Without the presence of a control group, a researcher cannot determine whether a particular treatment truly has an effect on an experimental group. Control groups are critical to the scientific method as they help ensure the internal validity of a study.