Detecting Hallucinations in Large Language Models via Internal Attention Divergence Signals

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
1. Verfasser: van Dijk, Gijs
Format: Preprint
Veröffentlicht: 2026
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866911652606115840
author van Dijk, Gijs
author_facet van Dijk, Gijs
contents We propose a lightweight and single-pass uncertainty quantification method for detecting hallucinations in Large Language Models. The method uses attention matrices to estimate uncertainty without requiring repeated sampling or external models. Specifically, we measure the Kullback-Leibler divergence between each attention head's distribution and a uniform reference distribution, and use these features in a logistic regression probe. Across multiple datasets, task types, and model families, attention divergence is highly predictive of answer correctness and performs competitively with existing uncertainty estimation methods. We find that this signal is concentrated in middle layers and on factual tokens such as named entities and numbers, suggesting that attention dynamics provides an efficient and interpretable white-box signal of model uncertainty.
format Preprint
id arxiv_https___arxiv_org_abs_2605_05025
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Detecting Hallucinations in Large Language Models via Internal Attention Divergence Signals
van Dijk, Gijs
Computation and Language
We propose a lightweight and single-pass uncertainty quantification method for detecting hallucinations in Large Language Models. The method uses attention matrices to estimate uncertainty without requiring repeated sampling or external models. Specifically, we measure the Kullback-Leibler divergence between each attention head's distribution and a uniform reference distribution, and use these features in a logistic regression probe. Across multiple datasets, task types, and model families, attention divergence is highly predictive of answer correctness and performs competitively with existing uncertainty estimation methods. We find that this signal is concentrated in middle layers and on factual tokens such as named entities and numbers, suggesting that attention dynamics provides an efficient and interpretable white-box signal of model uncertainty.
title Detecting Hallucinations in Large Language Models via Internal Attention Divergence Signals
topic Computation and Language
url https://arxiv.org/abs/2605.05025