Which statement correctly differentiates an independent design from a repeated-measures design?

Which statement correctly differentiates an independent design from a repeated-measures design?

• A. Independent design uses the same participants across all conditions
• B. Repeated-measures design uses different participants for each condition
• C. Independent design uses different participants for different conditions
• D. Repeated-measures design cannot test interactions

Answer: (C)

The key distinction is how participants are allocated to conditions. An independent design uses different participants for each condition, so no one participates in every condition. This avoids carryover effects between conditions but can require a larger total sample and relies on random assignment to keep groups comparable. That description is why the correct statement is the best one. Using the same participants across all conditions describes a repeated-measures design, not an independent one. Conversely, stating that different participants are used for different conditions describes an independent design, not repeated. And while some assume repeated-measures can’t test interactions, they can in factorial designs that include multiple factors measured across conditions; that idea is not accurate.

The key distinction is how participants are allocated to conditions. An independent design uses different participants for each condition, so no one participates in every condition. This avoids carryover effects between conditions but can require a larger total sample and relies on random assignment to keep groups comparable. That description is why the correct statement is the best one.

Using the same participants across all conditions describes a repeated-measures design, not an independent one. Conversely, stating that different participants are used for different conditions describes an independent design, not repeated. And while some assume repeated-measures can’t test interactions, they can in factorial designs that include multiple factors measured across conditions; that idea is not accurate.