arXiv AI
Oct 15

A, B, C, or Stable? Accuracy and Order Sensitivity Diverge in LLM Multiple-Choice Evaluation

The paper investigates whether accuracy and order sensitivity in large language model (LLM) multiple‑choice question (MCQ) evaluation move together. Using proprietary and open‑weight models on MMLU and ARC‑Challenge, the authors measure order sensitivity with flip rate and recall standard deviation (RStd) and find that these metrics often diverge from accuracy and from each other. They conclude that accuracy alone is insufficient and recommend reporting both flip rate and RStd alongside accuracy.

By Karl Hanna, Chen Feng
arXiv Computation and Language
Oct 19

On the Position Bias of Large Language Models: A Comprehensive Study

The paper investigates position bias in large language models (LLMs) across a wide range of model sizes—from billions to trillions of parameters—and across five languages. It finds that while small-scale models and non‑English languages still exhibit noticeable position bias, larger models and the use of Chain‑of‑Thought prompting substantially reduce this bias. Additionally, the study shows that emerging thinking models with advanced reasoning capabilities are almost immune to position bias, indicating a promising but resource‑intensive path to mitigating this vulnerability.

By Yining Li, Huayang Li, Lemao Liu, Taro Watanabe