Fact-Checking the Output of Large Language Models via Token-Level Uncertainty Quantification

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Auteurs principaux: Fadeeva, Ekaterina, Rubashevskii, Aleksandr, Shelmanov, Artem, Petrakov, Sergey, Li, Haonan, Mubarak, Hamdy, Tsymbalov, Evgenii, Kuzmin, Gleb, Panchenko, Alexander, Baldwin, Timothy, Nakov, Preslav, Panov, Maxim
Format: Preprint
Publié: 2024
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author Fadeeva, Ekaterina
Rubashevskii, Aleksandr
Shelmanov, Artem
Petrakov, Sergey
Li, Haonan
Mubarak, Hamdy
Tsymbalov, Evgenii
Kuzmin, Gleb
Panchenko, Alexander
Baldwin, Timothy
Nakov, Preslav
Panov, Maxim
author_facet Fadeeva, Ekaterina
Rubashevskii, Aleksandr
Shelmanov, Artem
Petrakov, Sergey
Li, Haonan
Mubarak, Hamdy
Tsymbalov, Evgenii
Kuzmin, Gleb
Panchenko, Alexander
Baldwin, Timothy
Nakov, Preslav
Panov, Maxim
contents Large language models (LLMs) are notorious for hallucinating, i.e., producing erroneous claims in their output. Such hallucinations can be dangerous, as occasional factual inaccuracies in the generated text might be obscured by the rest of the output being generally factually correct, making it extremely hard for the users to spot them. Current services that leverage LLMs usually do not provide any means for detecting unreliable generations. Here, we aim to bridge this gap. In particular, we propose a novel fact-checking and hallucination detection pipeline based on token-level uncertainty quantification. Uncertainty scores leverage information encapsulated in the output of a neural network or its layers to detect unreliable predictions, and we show that they can be used to fact-check the atomic claims in the LLM output. Moreover, we present a novel token-level uncertainty quantification method that removes the impact of uncertainty about what claim to generate on the current step and what surface form to use. Our method Claim Conditioned Probability (CCP) measures only the uncertainty of a particular claim value expressed by the model. Experiments on the task of biography generation demonstrate strong improvements for CCP compared to the baselines for seven LLMs and four languages. Human evaluation reveals that the fact-checking pipeline based on uncertainty quantification is competitive with a fact-checking tool that leverages external knowledge.
format Preprint
id arxiv_https___arxiv_org_abs_2403_04696
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Fact-Checking the Output of Large Language Models via Token-Level Uncertainty Quantification
Fadeeva, Ekaterina
Rubashevskii, Aleksandr
Shelmanov, Artem
Petrakov, Sergey
Li, Haonan
Mubarak, Hamdy
Tsymbalov, Evgenii
Kuzmin, Gleb
Panchenko, Alexander
Baldwin, Timothy
Nakov, Preslav
Panov, Maxim
Computation and Language
Artificial Intelligence
Machine Learning
Large language models (LLMs) are notorious for hallucinating, i.e., producing erroneous claims in their output. Such hallucinations can be dangerous, as occasional factual inaccuracies in the generated text might be obscured by the rest of the output being generally factually correct, making it extremely hard for the users to spot them. Current services that leverage LLMs usually do not provide any means for detecting unreliable generations. Here, we aim to bridge this gap. In particular, we propose a novel fact-checking and hallucination detection pipeline based on token-level uncertainty quantification. Uncertainty scores leverage information encapsulated in the output of a neural network or its layers to detect unreliable predictions, and we show that they can be used to fact-check the atomic claims in the LLM output. Moreover, we present a novel token-level uncertainty quantification method that removes the impact of uncertainty about what claim to generate on the current step and what surface form to use. Our method Claim Conditioned Probability (CCP) measures only the uncertainty of a particular claim value expressed by the model. Experiments on the task of biography generation demonstrate strong improvements for CCP compared to the baselines for seven LLMs and four languages. Human evaluation reveals that the fact-checking pipeline based on uncertainty quantification is competitive with a fact-checking tool that leverages external knowledge.
title Fact-Checking the Output of Large Language Models via Token-Level Uncertainty Quantification
topic Computation and Language
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2403.04696