Within-subject design is another name for which design?

• A. Between-subject design.
• B. Repeated-measures design.
• C. Cross-sectional design.
• D. Nested design.

Answer: (B)

Within-subject design means testing the same participants under every condition. This is the essence of a repeated-measures design, where each person serves as their own control across all experimental conditions. Because the same individuals are measured multiple times, the impact of individual differences on the outcome is reduced, which often gives more statistical power and cleaner comparisons. Of course, this approach can introduce carryover or order effects, so researchers counterbalance the order of conditions or include washout periods to minimize these issues. The other designs described involve different participants for each condition (between-subject), assess groups at a single point in time (cross-sectional), or deal with hierarchical data structures (nested). So, testing the same people across all conditions is the hallmark of a repeated-measures, or within-subject, design.