What is meant by the term 'control group' in an experiment?

The term 'control group' in an experiment refers to a group that does not receive the treatment being tested. This group serves as a baseline to compare the effects of the treatment on the experimental group that does receive the treatment. By not receiving the treatment, the control group helps researchers determine the natural state or behavior of the participants without the influence of the experimental conditions. This allows for a clearer understanding of any changes or effects that occur as a result of the treatment, making it easier to attribute any observed changes directly to the treatment itself rather than external factors.

In contrast, a group that receives multiple treatments would likely introduce complexity that detracts from identifying the specific impact of any single treatment. A group that is dependent on results from other groups does not serve the purpose of comparison needed for a control group, as it may skew the results. Lastly, a group that determines the overall outcome of the experiment suggests a level of judgment or conclusion-making that is not a characteristic of what a control group is designed to do; rather, it provides comparative data essential for evaluating the treatment group’s results.