Which of the following is a potential disadvantage of within-groups designs?

- demand characteristics

- nonequivalent groups

- requirement of more participants

- less statistical power

The answer is: demand characteristics

Demand characteristics refers to a situation when the subjects in an experiment change their own behavior in order to fulfill the expectations of the researchers.

In within group designs, same subjects are required to follow several different tests by the researchers. When this happen, there will be some subjects will be able to catch up about the things that the researchers want to find out and may change their behavior in order to be seen as favorable by the researchers.