In the Watson and Hughes study, which experimental design is used?

• A. Multiple-baseline design
• B. Between-subjects design
• C. Within-subjects design
• D. Mixed between- and within-subjects design

Answer: (C)

This question is about a within-subjects design, where the same participants experience every condition or measurement in the study. The key advantage is that each person serves as their own control, so differences between individuals don’t cloud the comparison of conditions. This makes it easier to detect the effect of the manipulation because the main source of variability—individual differences in behavior or baseline responses—has less impact on the results. In the Watson and Hughes study, using the same participants across different conditions or time points would let the researchers directly compare how each child responds under each condition, which strengthens the precision and efficiency of the findings.

Another benefit is needing fewer participants overall, since each participant contributes data to multiple conditions. However, this design can introduce carryover or order effects, where the experience of one condition influences responses to subsequent conditions. Researchers counteract this with counterbalancing the order of conditions, randomizing presentation, or including washout periods to minimize such effects.