Within-groups designs reduce error due to differences between the groups by using the same participants in each group.If differences are then observed between the groups, those differences are attributed to:
A) extraneous variables.
B) differences between participants.
C) failure to control other important variables.
D) the manipulation of the independent variable.

Question

Quizplus · Accepted Answer

Within-groups designs use the same participants in each group, so any observed differences between the groups can only be attributed to the manipulation of the independent variable. This is because any differences between participants or extraneous variables are controlled for by using the same individuals in each group. Differences due to failure to control other important variables would not be a valid explanation in a well-designed within-groups study.

Within-Groups Designs Reduce Error Due to Differences Between the Groups