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

The control group serves an essential function in experimental design by allowing scientists to establish a baseline for comparison. This group is exposed to all the same conditions as the experimental group, except for the independent variable being tested. By doing so, researchers can determine whether the changes observed in the experimental group are truly a result of the treatment or intervention being tested, rather than other extraneous factors.

For example, if a researcher is testing a new fertilizer on plant growth, the control group would consist of plants that do not receive the fertilizer. By measuring and comparing the growth of these control plants to those that received the fertilizer, the researcher can draw more accurate conclusions about the effectiveness of the fertilizer. This comparison is crucial for establishing the validity of the experiment's outcomes.