Repeated Measures Design involves which of the following?

Repeated Measures Design involves which of the following?

• A. Each participant does the control condition AND the experimental condition.
• B. Each participant does only one condition.
• C. Participants are matched on key characteristics.
• D. Participants are assigned randomly to groups.

Answer: (A)

In a repeated measures design, the same participants take part in every condition, so each person experiences both the control and the experimental condition. Because the same individuals are measured under all conditions, differences due to personal characteristics are held constant, which makes it easier to detect the effect of the manipulation and often increases statistical power. It also means you typically need fewer participants overall. However, this setup can bring order effects—practice, fatigue, or carryover from one condition to the next—which researchers mitigate by counterbalancing or randomizing the order of conditions. The other options don’t fit because one condition per participant describes a between-subjects (independent-groups) design, not repeated measures. Matching participants on characteristics is a strategy used to equate different groups in between-subjects designs, and random assignment to groups is also a feature of creating comparable groups in between-subjects designs.

In a repeated measures design, the same participants take part in every condition, so each person experiences both the control and the experimental condition. Because the same individuals are measured under all conditions, differences due to personal characteristics are held constant, which makes it easier to detect the effect of the manipulation and often increases statistical power. It also means you typically need fewer participants overall.

However, this setup can bring order effects—practice, fatigue, or carryover from one condition to the next—which researchers mitigate by counterbalancing or randomizing the order of conditions.

The other options don’t fit because one condition per participant describes a between-subjects (independent-groups) design, not repeated measures. Matching participants on characteristics is a strategy used to equate different groups in between-subjects designs, and random assignment to groups is also a feature of creating comparable groups in between-subjects designs.