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HALoGEN: Fantastic LLM Hallucinations and Where to Find Them

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arxiv 2501.08292 v1 pith:4VUTL42T submitted 2025-01-14 cs.CL cs.AI

HALoGEN: Fantastic LLM Hallucinations and Where to Find Them

classification cs.CL cs.AI
keywords modelshallucinationserrorsgenerationsgenerativeknowledgelanguagetype
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
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Despite their impressive ability to generate high-quality and fluent text, generative large language models (LLMs) also produce hallucinations: statements that are misaligned with established world knowledge or provided input context. However, measuring hallucination can be challenging, as having humans verify model generations on-the-fly is both expensive and time-consuming. In this work, we release HALoGEN, a comprehensive hallucination benchmark consisting of: (1) 10,923 prompts for generative models spanning nine domains including programming, scientific attribution, and summarization, and (2) automatic high-precision verifiers for each use case that decompose LLM generations into atomic units, and verify each unit against a high-quality knowledge source. We use this framework to evaluate ~150,000 generations from 14 language models, finding that even the best-performing models are riddled with hallucinations (sometimes up to 86% of generated atomic facts depending on the domain). We further define a novel error classification for LLM hallucinations based on whether they likely stem from incorrect recollection of training data (Type A errors), or incorrect knowledge in training data (Type B errors), or are fabrication (Type C errors). We hope our framework provides a foundation to enable the principled study of why generative models hallucinate, and advances the development of trustworthy large language models.

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Cited by 6 Pith papers

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