What is the term for a group that does not receive treatment in an experiment?

The term for a group that does not receive treatment in an experiment is known as the control group. The primary purpose of this group is to serve as a benchmark against which the effects of the treatment can be measured. By not exposing the control group to the experimental treatment, researchers can determine if changes in the experimental group are due to the treatment itself or other factors. The control group helps to ensure that the results are valid and that any observed effects can be attributed specifically to the treatment being tested. In contrast, other groups, such as the experimental or test groups, do receive the treatment or manipulation being investigated. Thus, the control group is essential for establishing a comparison point in any experimental design.