What is a Control Group? -Voxco

The use of control groups is critical in experimental design. When researchers want to see how a new treatment affects people, they divide them into at least two groups at random:

The treatment group (also known as the experimental group) gets the treatment that the researcher is interested in.

The control group is given either no treatment, a standard treatment with a recognised effect, or a placebo (a fake treatment).

The treatment is any independent variable that the experimenters manipulate, and the specific form of the treatment depends on the sort of research being conducted. It could be a novel medicine or therapy in a medical trial. It might be a new social policy that some people get and others don’t, according to public policy studies.

Consider a treatment group that receives a vaccination and has a 10% infection rate. You can’t tell if that’s an improvement on its own. However, if you include an unvaccinated control group with a 20% infection rate, you can see that the vaccine improved the outcome by 10%.

The control group indicates the treatment’s effect by providing a baseline for comparison. A control group and at least one treatment group are usually included in most research. In an ideal experiment, all individuals in all groups begin with the same basic features, with the exception that those in the treatment groups are given a therapy. You can ascribe differences after the experiment to the treatments if the groups are otherwise equivalent before treatment begins.

There may be more than one treatment or control group in a study. Researchers may want to look at the effects of many treatments at the same time, or compare a new treatment to several existing options.