Which term refers to stable individual differences among participants that can confound results if not controlled?

Which term refers to stable individual differences among participants that can confound results if not controlled?

• A. Participant variables
• B. Baseline measure
• C. Debriefing
• D. Placebo group

Answer: (A)

Stable individual differences among participants that can influence outcomes regardless of the experimental manipulation are called participant variables. These are inherent traits or characteristics that vary across people—things like age, gender, IQ, motivation, prior experience, or health status. Because these differences are not caused by the experimental manipulation, they can shift the outcome in one direction or another and masquerade as effects of the treatment if groups aren’t made equivalent. That’s why researchers try to control for them through methods such as random assignment, matching, or within-subjects designs, which help ensure that any observed effects are more likely due to the manipulation rather than preexisting differences. A baseline measure refers to an initial assessment of the dependent variable before the manipulation to track change, not to inherent differences between participants. Debriefing is the post-study explanation given to participants. A placebo group is a control condition used to account for expectancy effects, not to label stable participant differences.

Stable individual differences among participants that can influence outcomes regardless of the experimental manipulation are called participant variables. These are inherent traits or characteristics that vary across people—things like age, gender, IQ, motivation, prior experience, or health status. Because these differences are not caused by the experimental manipulation, they can shift the outcome in one direction or another and masquerade as effects of the treatment if groups aren’t made equivalent. That’s why researchers try to control for them through methods such as random assignment, matching, or within-subjects designs, which help ensure that any observed effects are more likely due to the manipulation rather than preexisting differences.

A baseline measure refers to an initial assessment of the dependent variable before the manipulation to track change, not to inherent differences between participants. Debriefing is the post-study explanation given to participants. A placebo group is a control condition used to account for expectancy effects, not to label stable participant differences.