Answer:
Use of a control group
Step-by-step explanation:
A common use of a control group is an experiment in which the effect of a treatment is uncertain and correlations are used to measure the impact of the treatment between the control group and the experimental group.
For example, in a pharmaceutical study to decide the efficacy of a new medicine on migraine treatment, the new drug will be administered to the experimental group and a placebo (a drug that is inert or assumed to have no effect) will be administered to the control group.