Uncertainty in Natural Language Processing: Sources, Quantification, and Applications
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Abstract (arXiv)
As a main field of artificial intelligence, natural language processing (NLP) has achieved remarkable success via deep neural networks. Plenty of NLP tasks have been addressed in a unified manner, with various tasks being associated with each other through sharing the same paradigm. However, neural networks are black boxes and rely on probability computation. Making mistakes is inevitable. Therefore, estimating the reliability and trustworthiness (in other words, uncertainty) of neural networks becomes a key research direction, which plays a crucial role in reducing models' risks and making better decisions. Therefore, in this survey, we provide a comprehensive review of uncertainty-relevant works in the NLP field. Considering the data and paradigms characteristics, we first categorize the sources of uncertainty in natural language into three types, including input, system, and output. Then, we systemically review uncertainty quantification approaches and the main applications. Finally, we discuss the challenges of uncertainty estimation in NLP and discuss potential future directions, taking into account recent trends in the field. Though there have been a few surveys about uncertainty estimation, our work is the first to review uncertainty from the NLP perspective.
Key facts. Cited by 44 papers in the map (data through 7 Oct 2026). Builds on 96 of its 156 references that are in the map. First posted on arXiv 5 Jun 2023.
Builds on
96 of 156 references.
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- 2024Internal Consistency and Self-Feedback in Large Language Models: A Survey19 Jul 2024
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- 2026Diagnosing LLM Arbitration Behavior over Pre-evidence Epistemic States in RAG-based Fact-Checking31 May 2026
- 2026Walking Through Uncertainty: An Empirical Study of Uncertainty Estimation for Audio-Aware Large Language Models28 Apr 2026
- 2026Why Don't You Know? Evaluating the Impact of Uncertainty Sources on Uncertainty Quantification in LLMs12 Apr 2026
- 2026When Should a Language Model Trust Itself? Same-Model Self-Verification as a Conditional Confidence Signal8 Apr 2026
- 2026RealBirdID: Benchmarking Bird Species Identification in the Era of MLLMs27 Mar 2026
- 2026Knowing When to Abstain: Medical LLMs Under Clinical Uncertainty18 Jan 2026
- 2026Uncertainty Quantification for Named Entity Recognition via Full-Sequence and Subsequence Conformal Prediction13 Jan 2026
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- 2025Using Large Language Models for Legal Decision-Making in Austrian Value-Added Tax Law: A Comparative Study11 Jul 2025
- 2025Revisiting Epistemic Markers in Confidence Estimation: Can Markers Accurately Reflect Large Language Models' Uncertainty?30 May 2025
- 2025Is Your Model Fairly Certain? Uncertainty-Aware Fairness Evaluation for LLMs29 May 2025
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