arXiv Computation and Language By Ningzhi Li, Xiaojun Ma, Xiaofei Wang

Detecting Errors in Large Language Model Responses: The Incremental Predictive Value of Hidden States

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The paper investigates whether the internal hidden states of large language models can improve the detection of hallucinations in model responses. By integrating hidden states with an output‑side baseline and evaluating on both open‑ended generation and multiple‑choice tasks, the authors find that adding hidden states yields modest AUROC gains of about 0.004 and 0.039. These results suggest that while hidden states contain additional predictive information, the overall improvement over strong standalone detection methods remains limited.

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