a comparison group in a scientific experiment (e.g., a clinical drug trial) that is used to verify experimental results. A control group is not subject to the intervention under (e.g., not given a drug) so that those receiving the intervention and those not receiving it may be compared. Contrast with treatment arm.
The group of participants in a clinical trial who receive standard treatment or a placebo, against which those receiving the experimental treatment are compared.
A group of women in a trial; the control group follows the established screening pattern, and are compared with women undergoing trial conditions in the study arm.