Choosing a “control group” (the group who doesn’t receive the treatment or other thing being tested) who is like the “experimental group” (who does receive the treatment); the groups would be alike in gender, age, race, and severity of disability, for example.
The process of making a study group and a comparison (control) group comparable with respect to certain factors that are not part of the main hypothesis. Matching is often done on such characteristics as age, sex, race, income group, etc. and is included into the study design to prevent the matched variables from affecting the estimate of risk and ultimately the conclusions of the study.
A method utilized to create comparison groups, in which groups or individuals are matched to those in the treatment group based on characteristics felt to be relevant to program outcomes.