Language Models (Mostly) Know What They Know
Saurav KadavathTom ConerlyAmanda AskellTom HenighanDawn DrainEthan PerezNicholas SchieferZac Hatfield-DoddsNova DasSarmaEli Tran-Johnson
Demonstrates that larger language models can reliably evaluate the correctness of their own generated statements and predict whether they know the answer to a question, providing an empirical basis for training more honest AI.
As artificial intelligence systems are deployed into high-stakes environments, ensuring their honesty and factual reliability is essential. A core prerequisite for honest AI is self-knowledge: the ability of a system to accurately evaluate whether its own reasoning is sound and to determine whether it knows the answer to a given query. The article addresses this challenge by assessing how well large language models estimate their own capabilities and evaluate the truth of their own generated responses.
The article set out to evaluate whether language models are well-calibrated when estimating the validity of their claims and to demonstrate how models can be trained to predict whether they can answer a question correctly. To investigate these questions, the authors evaluated a suite of language models ranging from 800 million to 52 billion parameters across a wide array of benchmarks, including multiple-choice datasets (such as BIG Bench and MMLU) and open-ended generative tasks spanning trivia, arithmetic, story completion, and Python code generation.
The findings establish five central conclusions. First, large models are remarkably well-calibrated on multiple-choice and True/False tasks when choices are formatted with explicit lettered options, and this calibration consistently improves with model size and few-shot prompting. Second, when models are asked to evaluate their own generated answers by predicting the probability that a response is correct, they effectively separate true statements from errors; filtering for answers with greater than 50% confidence substantially increases task accuracy. Third, self-evaluation improves markedly when the model is allowed to inspect several brainstormed sample answers before judging a specific candidate. Fourth, models can be finetuned with a specialized value head to predict the probability that they know an answer before generating it; this prediction capability generalizes to new domains, increases when relevant source text or mathematical hints are provided, and decreases when distracting hints are presented. Finally, the authors show that poorly calibrated models refined via human feedback can be restored to strong calibration using a simple probability temperature adjustment.
These results demonstrate that larger language models inherently possess significant latent self-knowledge, with verification capability improving faster than generation ability as models scale. For leaders and practitioners, this implies that organizations can deploy confidence thresholds and multi-sample self-evaluation workflows to mitigate hallucination risks and boost system reliability without retraining underlying architectures. Furthermore, the findings show that models can dynamically evaluate whether available background materials provide sufficient information to answer a prompt.
Moving forward, developers should implement few-shot True/False verification and multi-sample comparison prompts to filter generative outputs in production pipelines. However, decision-makers should note key limitations: out-of-distribution calibration remains brittle, the current approach relies on pretraining that mimics human text rather than establishing objective truth, and the techniques do not yet guard against intentional deception. Additional research and pilot testing are recommended to evaluate how these self-evaluation mechanisms function under intense reinforcement learning and across more specialized real-world domains.
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- Paper: Self-Refine: Iterative Refinement with Self-Feedback, Aman Madaan et al. (2023). Applies the model's self-evaluation capabilities dynamically in an iterative generation, feedback, and self-correction loop.
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- Paper: On-Policy Self-Distillation without Any Supervision, Yijiang Li et al.. Leverages self-generated consensus and consistency checks across independent model rollouts to achieve entirely unsupervised self-distillation.
