What is a control group?

A control group is defined as a group that serves as a baseline for comparison in an experiment. This group does not receive the treatment or intervention that is being tested; instead, it is used to measure the effects of the treatment on the experimental group. By placing the control group alongside the experimental group, researchers can determine whether any observed effects in the experimental group are due to the treatment or other factors.

The importance of having a control group lies in its role in isolating the variable being tested. Without a control group, it would be difficult to ascertain whether the results are truly due to the intervention or if they could be attributed to other variables. This helps ensure the validity and reliability of the experimental results, allowing researchers to draw more accurate conclusions based on the data collected.

In contrast, the other choices describe different aspects of research that do not pertain to the specific function of a control group. For instance, a group that receives the treatment is known as the experimental group, whereas a group providing data for qualitative analysis does not fit within the typical structure of experimental research involving control and experimental groups. Similarly, varied demographics pertain to participant characteristics but do not define the fundamental role of a control group.