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

The role of a control group in an experiment is crucial as it serves as a baseline for comparison. By having a control group, researchers establish a standard to which they can compare the results of the experimental group that undergoes a treatment or intervention. This helps to determine if the effects observed in the experimental group are actually due to the manipulation of the independent variable, rather than other factors.

For instance, if an experiment aims to test the effectiveness of a new drug, the control group would typically receive a placebo, while the experimental group receives the actual drug. By comparing the outcomes between these two groups, researchers can make more reliable conclusions about the drug’s efficacy. The control group effectively isolates the variable being tested and helps to ensure that any observed changes in the experimental group are attributable to the treatment itself.

The other options do not accurately describe the role of a control group. Introducing variability, manipulating the dependent variable, or providing hypotheses for testing are not functions of the control group within the experimental design. These roles are typically associated with other aspects of experimental methodology but do not pertain to the purpose of the control group.