What is the purpose of a control group in an experiment?

The purpose of a control group in an experiment is to serve as a baseline for comparison. In scientific research, a control group is a standard against which the effectiveness of the experimental treatment or condition can be measured. By not exposing the control group to the independent variable being tested, researchers can observe how the experimental group differs when the variable is applied.

This comparison helps to establish whether any changes observed in the experimental group are actually due to the manipulation of the independent variable, rather than other external factors. Essentially, the control group helps ensure that the results of the experiment are valid and that any observed effects can be attributed to the treatment rather than random chance.

In contrast, manipulating variables is the role of the experimental group, while introducing bias would undermine the integrity of the experiment. Errors in measurement can occur in both control and experimental groups, but they do not relate directly to the specific purpose of a control group. By having a control group, researchers can achieve a clearer understanding of the results derived from the experimental conditions.