Paper 2 · Question 11

A: Recency bias would favour rows near the end of the data, not the 45th row. The 45th row is in the early portion of the result set, which is consistent with the lost-in-the-middle effect, not recency bias.

B: The lost-in-the-middle effect causes LLMs to attend disproportionately to content at the start and end of long sequences, with reduced attention to material in the middle. Row 142 (the correct answer) sits deep in the middle of the 200-row result set, making it prone to being overlooked.

C: If rows were truncated, the agent would not have access to row 142 at all and would report the highest margin from the visible rows. The agent identified a specific wrong row (45th), indicating all data is present but attention is uneven.

D: Anchoring bias is a human cognitive bias, not a well-documented LLM failure mode for structured data scanning. The observed behaviour — accurate recall at the start and end, poor recall in the middle — is the hallmark of the lost-in-the-middle effect.