Which group in an experiment does not receive any treatment?

The group in an experiment that does not receive any treatment is known as the control group. This group serves as a baseline for comparison with the experimental group, which is subjected to the treatment or intervention being tested.

Having a control group is essential for scientific research because it helps to isolate the effect of the treatment and determine whether any observed changes in the experimental group are truly due to the treatment rather than other factors. By comparing results between the control and experimental groups, researchers can more accurately identify the impact of the independent variable being studied.

In contrast, the experimental group receives the treatment, and the test group is essentially synonymous with the experimental group in many cases. The variable group is not a standard term used in this context and typically refers to elements within an experiment that can change, rather than a designated group for studying treatment effects.