Assignment bias can threaten the internal validity of between-subjects experiments.

Question

Assignment bias can threaten the internal validity of between-subjects experiments.​

Quizplus · Accepted Answer

Assignment bias occurs when participants are not assigned to groups randomly and, as a result, group differences may be due to pre-existing differences between groups rather than the experimental manipulation. This threatens the internal validity of between-subjects experiments because it undermines the ability to draw causal conclusions.

Assignment Bias Can Threaten the Internal Validity of Between-Subjects Experiments