Which is a disadvantage of Independent Groups Design?

• A. This design eliminates demand characteristics.
• B. Individual differences can occur.
• C. It requires no participants.
• D. It is always quicker to run.

Answer: (B)

In an Independent Groups (between-subjects) design, different participants take part in each condition. The main drawback is that individual differences between people become a source of variability that can influence the outcome, making it harder to tell whether any observed effect is due to the manipulation or to differences between groups (such as baseline abilities, personality, or prior experience). This extra noise reduces statistical power and often means you need a larger sample to detect real effects, even with random assignment trying to balance groups. It’s not true that this design automatically eliminates demand characteristics, and it still requires participants and isn’t inherently quicker to run than other designs.