The design where the same participants take part in all experimental conditions is known as:

The design where the same participants take part in all experimental conditions is known as:

• A. Repeated-measures design
• B. Between-subjects design
• C. Cross-sectional design
• D. Matched-pairs design

Answer: (A)

Same participants across all conditions means each person acts as their own control, which helps remove the influence of individual differences on the outcome and boosts statistical power. This setup is called a repeated-measures design. It’s efficient because you need fewer participants and you get cleaner comparisons between conditions since the same people experience every condition. However, it can introduce order effects or carryover effects—what happens in one condition can affect responses in another. To address this, researchers typically counterbalance the order of conditions, randomize sequences, or include washout periods. In contrast, designs where different participants are in different conditions (between-subjects) introduce more participant variability and don’t have the same carryover concerns. A cross-sectional design is typically observational and assesses different groups at one point in time, not the same individuals under multiple conditions. A matched-pairs design uses pairs of participants matched on characteristics and then assigns each member of a pair to a different condition, so participants are not in all conditions.

Same participants across all conditions means each person acts as their own control, which helps remove the influence of individual differences on the outcome and boosts statistical power. This setup is called a repeated-measures design. It’s efficient because you need fewer participants and you get cleaner comparisons between conditions since the same people experience every condition.

However, it can introduce order effects or carryover effects—what happens in one condition can affect responses in another. To address this, researchers typically counterbalance the order of conditions, randomize sequences, or include washout periods.

In contrast, designs where different participants are in different conditions (between-subjects) introduce more participant variability and don’t have the same carryover concerns. A cross-sectional design is typically observational and assesses different groups at one point in time, not the same individuals under multiple conditions. A matched-pairs design uses pairs of participants matched on characteristics and then assigns each member of a pair to a different condition, so participants are not in all conditions.