Reducing Detail Hallucinations in Long-Context Regulatory Understanding via Targeted Preference Optimization

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Liu, Yang, Chong, Bin, Lin, Yuhan, Zhang, Chongyang, Zheng, Hao, Zhang, Ziyi, Liang, Jiayu, Ran, Ran, Li, Qian, Xu, Kefu
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910165713813504
author Liu, Yang
Chong, Bin
Lin, Yuhan
Zhang, Chongyang
Zheng, Hao
Zhang, Ziyi
Liang, Jiayu
Ran, Ran
Li, Qian
Xu, Kefu
author_facet Liu, Yang
Chong, Bin
Lin, Yuhan
Zhang, Chongyang
Zheng, Hao
Zhang, Ziyi
Liang, Jiayu
Ran, Ran
Li, Qian
Xu, Kefu
contents Large language models (LLMs) frequently produce \emph{detail hallucinations} when processing long regulatory documents, including subtle errors in threshold values, units, scopes, obligation levels, and conditions that preserve surface plausibility while corrupting safety-critical parameters. We formalize this phenomenon through a fine-grained \emph{Detail Error Taxonomy} of five error types and introduce \textbf{DetailBench}, a benchmark built from 172 real regulatory documents and 150 synthetic documents spanning three jurisdictions, with human-annotated detail-level ground truth comprising 13,000 preference pairs. We propose \textbf{DetailDPO}, a targeted preference optimization framework that constructs contrastive pairs differing in exactly one detail dimension, concentrating DPO gradient signal on detail-bearing~tokens. We provide theoretical analysis showing why \emph{minimal detail perturbation} pairs yield gradient concentration under mild assumptions. Experiments on the Qwen2.5 family (7B, 14B, 72B) and Llama-3.1-8B across three context-length tiers (8K--64K tokens) show that DetailDPO reduces the Detail Error Rate by 42--61\% relative to baselines, with consistent gains across all five error types and cross-domain transfer to financial and medical documents.
format Preprint
id arxiv_https___arxiv_org_abs_2604_23113
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Reducing Detail Hallucinations in Long-Context Regulatory Understanding via Targeted Preference Optimization
Liu, Yang
Chong, Bin
Lin, Yuhan
Zhang, Chongyang
Zheng, Hao
Zhang, Ziyi
Liang, Jiayu
Ran, Ran
Li, Qian
Xu, Kefu
Social and Information Networks
Large language models (LLMs) frequently produce \emph{detail hallucinations} when processing long regulatory documents, including subtle errors in threshold values, units, scopes, obligation levels, and conditions that preserve surface plausibility while corrupting safety-critical parameters. We formalize this phenomenon through a fine-grained \emph{Detail Error Taxonomy} of five error types and introduce \textbf{DetailBench}, a benchmark built from 172 real regulatory documents and 150 synthetic documents spanning three jurisdictions, with human-annotated detail-level ground truth comprising 13,000 preference pairs. We propose \textbf{DetailDPO}, a targeted preference optimization framework that constructs contrastive pairs differing in exactly one detail dimension, concentrating DPO gradient signal on detail-bearing~tokens. We provide theoretical analysis showing why \emph{minimal detail perturbation} pairs yield gradient concentration under mild assumptions. Experiments on the Qwen2.5 family (7B, 14B, 72B) and Llama-3.1-8B across three context-length tiers (8K--64K tokens) show that DetailDPO reduces the Detail Error Rate by 42--61\% relative to baselines, with consistent gains across all five error types and cross-domain transfer to financial and medical documents.
title Reducing Detail Hallucinations in Long-Context Regulatory Understanding via Targeted Preference Optimization
topic Social and Information Networks
url https://arxiv.org/abs/2604.23113