Control group comparison baseline – UGC NET Question

The control group is included in an experiment to provide a baseline against which the effects of the experimental treatment can be judged. It either receives no treatment or a standard condition, while the experimental group receives the new or varied treatment. Any differences in outcomes between the groups can then be attributed more confidently to the manipulation of the independent variable. Thus, the group described in the stem is correctly called the control group.

Option A:
Control groups help isolate the effect of the independent variable by holding all other conditions as constant as possible. They strengthen internal validity by allowing researchers to rule out alternative explanations such as maturation or history. This critical comparison role matches the definition given in the question.

Option B:
The experimental group is the set of participants that receives the treatment or intervention under investigation. It does not serve as the baseline but rather as the group whose outcomes are compared with those of the control group. Hence, experimental group is not the correct completion.

Option C:
Random group is not a standard term in experimental design; randomness refers instead to the method of assigning participants to groups. While random assignment is important, it does not name the specific group that receives no or standard treatment. Therefore, random group is inappropriate here.

Option D:
A matched group refers to participants paired or grouped based on similar characteristics to control for confounding variables, but such groups may still be either experimental or control groups. The term does not by itself identify the no-treatment comparison group described in the stem.