is a group of participants in a study who are as similar as possible to the experimental group (for example in age, sex, education, and other relevant characteristics) but do not receive the treatment or intervention being tested. The control group provides a baseline for comparison, allowing researchers to determine whether observed effects in the experimental group are due to the intervention itself rather than other factors.
Synonyms: Comparison Group, Reference Group, Baseline Group
Example
In a clinical trial of a new arthritis medication, participants are randomly assigned to either the experimental group (receiving the new drug) or the control group (receiving a placebo). Differences in outcomes between the two groups show whether the new drug has a true effect.