In a between-subjects experiment, if the participants in one group are noticeably more intelligent than the participants in another group, then participant intelligence is a confounding variable and threatens the internal validity of the experiment.

Question

Quizplus · Accepted Answer

If there are differences in participant characteristics, such as intelligence, between groups in a between-subjects experiment, it can be difficult to determine whether any observed differences in the outcome variable are due to the independent variable or the confounding variable. This threatens the internal validity of the experiment because it makes it difficult to draw conclusions about cause and effect relationships.

In a Between-Subjects Experiment, If the Participants in One Group