Which design uses the same participants across all conditions?

Which design uses the same participants across all conditions?

• A. Within-subjects
• B. Between-subjects
• C. Mixed-subjects
• D. Repeated measures

Answer: (A)

In a within-subjects design, the same participants experience every condition. This means each person serves as their own control, which minimizes variability due to who the participant is and increases the experiment’s sensitivity to detect the effect of the manipulation. Because participants go through multiple conditions, order can influence outcomes, so researchers often counterbalance or randomize the sequence to balance potential order effects. This design can have higher power with fewer participants, but it also carries risks like carryover, practice, or fatigue effects, which researchers address with careful scheduling or washout periods. Repeated measures is another way people describe testing the same subjects across time or conditions, but within-subjects is the standard label for a design where every participant experiences every condition.

In a within-subjects design, the same participants experience every condition. This means each person serves as their own control, which minimizes variability due to who the participant is and increases the experiment’s sensitivity to detect the effect of the manipulation. Because participants go through multiple conditions, order can influence outcomes, so researchers often counterbalance or randomize the sequence to balance potential order effects. This design can have higher power with fewer participants, but it also carries risks like carryover, practice, or fatigue effects, which researchers address with careful scheduling or washout periods. Repeated measures is another way people describe testing the same subjects across time or conditions, but within-subjects is the standard label for a design where every participant experiences every condition.