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

The role of a control group in an experiment is indeed to provide results for comparison. A control group remains unchanged and does not receive the experimental treatment; it serves as a baseline against which the effects of the independent variable can be measured. By comparing the results from the experimental group (which is exposed to the independent variable) with those from the control group, researchers can determine whether any observed changes in the dependent variable are due to the manipulation of the independent variable or other outside factors. This comparative aspect is crucial for validating the findings of the experiment and ensuring that the conclusions drawn are based on accurate and reliable data.

The other options focus on different aspects of the experimental design. Testing the independent variable is the purpose of the experimental group rather than the control group itself. Controlling the dependent variable is necessary for a well-designed experiment but does not specifically refer to the function of the control group alone. Manipulating outcomes goes against the fundamental ethics of scientific experimentation, which strives for objective observation and reliable results. The comparison provided by the control group is what allows researchers to maintain integrity and rigor in their findings.