control group
Used in scientific experiments to refer to the group that does not receive the treatment, serving as a baseline for comparison.
この研究では、対照群にはプラセボを投与した。
In this study, the control group received a placebo.
対照群と実験群の結果を比較する。
Compare the results of the control group and the experimental group.
Compound of 対照 (comparison, contrast) and 群 (group). The term is a direct conceptual borrowing from English 'control group'.