Which order effect is stronger in one particular sequence, making counterbalancing ineffective?

• A. Asymmetrical order effect
• B. Carryover effect
• C. Practice effect
• D. Sequence bias

Answer: (A)

Order effects arise when the sequence in which conditions are presented changes responses. Counterbalancing rests on the idea that any such effects are similar in all orders or cancel out when averaged across orders. When an order effect is asymmetrical, its impact is stronger in one particular sequence than in the reverse. That means one ordering can push results in a different direction more than the opposite ordering, so simply rotating or averaging sequences won’t fully cancel the bias. In this situation, counterbalancing becomes ineffective at removing the influence of the order, which is why this type of effect is the best answer.