Know the Unknown: An Uncertainty-Sensitive Method for LLM Instruction Tuning

Fuente: arXiv
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Main Authors: Li, Jiaqi, Tang, Yixuan, Yang, Yi
Format: Preprint
Published: 2024
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author Li, Jiaqi
Tang, Yixuan
Yang, Yi
author_facet Li, Jiaqi
Tang, Yixuan
Yang, Yi
contents Large language models (LLMs) demonstrate remarkable capabilities but face challenges from hallucinations, which typically arise from insufficient knowledge or context. While instructing LLMs to acknowledge knowledge limitations by responding with "I don't know" appears promising, we find that models consistently struggle with admitting knowledge gaps. This challenge may originate from current instruction datasets that emphasise answer generation over knowledge boundary awareness. To address this limitation, we introduce Uncertainty-and-Sensitivity-Aware Tuning (US-Tuning), a novel two-stage approach for contextual question answering (QA). The first stage enhances LLMs' ability to recognise their knowledge boundaries, while the second stage reinforces instruction adherence through carefully designed causal prompts. Our experimental results demonstrate that US-Tuning not only significantly reduces incorrect answers in contextual QA but also improves models' faithfulness to their parametric knowledge, mitigating hallucinations in general QA tasks. Our fine-tuned Llama2-7B model achieves up to a 34.7% improvement in handling out-of-knowledge questions and outperforms GPT-4 by 4.2% in overall performance.
format Preprint
id arxiv_https___arxiv_org_abs_2406_10099
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Know the Unknown: An Uncertainty-Sensitive Method for LLM Instruction Tuning
Li, Jiaqi
Tang, Yixuan
Yang, Yi
Computation and Language
Large language models (LLMs) demonstrate remarkable capabilities but face challenges from hallucinations, which typically arise from insufficient knowledge or context. While instructing LLMs to acknowledge knowledge limitations by responding with "I don't know" appears promising, we find that models consistently struggle with admitting knowledge gaps. This challenge may originate from current instruction datasets that emphasise answer generation over knowledge boundary awareness. To address this limitation, we introduce Uncertainty-and-Sensitivity-Aware Tuning (US-Tuning), a novel two-stage approach for contextual question answering (QA). The first stage enhances LLMs' ability to recognise their knowledge boundaries, while the second stage reinforces instruction adherence through carefully designed causal prompts. Our experimental results demonstrate that US-Tuning not only significantly reduces incorrect answers in contextual QA but also improves models' faithfulness to their parametric knowledge, mitigating hallucinations in general QA tasks. Our fine-tuned Llama2-7B model achieves up to a 34.7% improvement in handling out-of-knowledge questions and outperforms GPT-4 by 4.2% in overall performance.
title Know the Unknown: An Uncertainty-Sensitive Method for LLM Instruction Tuning
topic Computation and Language
url https://arxiv.org/abs/2406.10099