arXiv Computation and Language

Enoki: Efficient Multi-Level Hallucination Detection

arXiv AI
Sep 10

Evidence-Aligned Entity Verification for Hallucination Detection in Retrieval-Augmented Generation

The paper introduces Evidence-Aligned Entity Verification (EAEV), a method for detecting entity-level hallucinations in retrieval-augmented generation (RAG). EAEV aligns generated entities with retrieved evidence across three dimensions and uses counterfactual stability analysis to maintain robust alignments when evidence changes. Experiments on multiple RAG benchmarks show that EAEV consistently outperforms existing hallucination detection methods and generalizes well.

By Runsong Jia, Zhen Fang, Mengjia Wu, Jie Lu, Yi Zhang
arXiv Computation and Language
Oct 21

SHAM-Bench: A Span-level Hallucination Benchmark Across Multiple Tasks

The paper introduces SHAM-Bench, a unified benchmark for detecting span-level hallucinations across six natural language generation tasks, compiled from 6,461 human-annotated examples under a common schema. It evaluates existing detection methods, finding that fine‑tuned detectors perform well in‑domain but falter under distribution shift, while prompt‑based methods with reasoning show greater robustness. The study also highlights challenges such as subtle unsupported content, ambiguous span boundaries, and noisy labels, and releases the dataset, evaluation code, and a public leaderboard for future research.

By Sicong Huang, Ian Lane
arXiv AI
Oct 27

Mycelium: A Meta-Study of Hallucination Detection Across Provenance, Typology, and Granularities

The paper presents a meta‑study of hallucination detection in large language models, framing it as a benchmark‑conditioned measurement problem. It organizes existing benchmarks along three axes—provenance, typology, and granularity—to analyze how construction, annotation, and evaluation choices influence detection tasks. The authors also examine span‑level evaluation, propose a new Span Coverage F1 metric, and discuss the implications for cross‑benchmark comparisons and generalization.

By Julia Belikova, Elisei Rykov
arXiv Computation and Language
Oct 28

LLM Hallucination Detection via Low-rank Multilinear Decomposition

The paper introduces LOTUS, a low‑rank multilinear decomposition method for detecting hallucinations in large language models. LOTUS compresses variable‑length token representations into compact features using statistical descriptors of peak activations, distributions, and cross‑layer changes, then applies low‑rank decomposition to capture the underlying structure of hidden states. Experiments on several LLMs and QA benchmarks show that LOTUS outperforms recent state‑of‑the‑art hallucination detectors while requiring less labeled data.

By Devansh Sharma, Faizul Rakib Sayem, Shahana Ibrahim
arXiv Computation and Language
Oct 22

S-EDL: Eliciting Self-Evidence from Sequence Likelihoods for Semantic Calibration of LLMs

S-EDL is a new evidential method that calibrates large language models for open‑ended generation by using the model’s own sequence likelihoods to build a differentiable Dirichlet prior over prompt‑specific semantic classes. This approach optimizes an evidential loss that provides a calibration‑aware training signal without relying on fixed multiple‑choice options. Experiments on four open‑ended benchmarks and three models show that S-EDL reduces semantic calibration error and improves accuracy, offering a framework for trustworthy LLM deployment in complex applications.

By Yawei Li, Jiazheng Li, David R\"ugamer, Bernd Bischl, Yulan He, Mina Rezaei