What is the control group in a scientific experiment?
From Wikipedia: “Scientific controls allow experiments to study one variable at a time, and are a vital part of the scientific method. In a controlled experiment, two virtually identical experiments are conducted. In one of them, the treatment, the factor being tested is applied. In the other, the control, the factor being tested is not applied.[1] For example, in testing a drug, it is important to carefully verify that the supposed effects of the drug are produced only by the drug itself. Doctors achieve this with a double-blind study in a clinical trial: two (statistically) identical groups of patients are compared, one of which receives the drug and one of which receives a placebo. Neither the patients nor the doctor know which group receives the real drug, which serves both to curb bias and to isolate the effects of the drug.” So a control is something that you know how it should react. It serves as a baseline, from which you can determine if your treatment caused a detectable diff
