RAG and RAU: A Survey on Retrieval-Augmented Language Model in Natural Language Processing
On the map: Retrieval-augmented generation → Generation and context integration
Abstract (arXiv)
Large Language Models (LLMs) have catalyzed significant advancements in Natural Language Processing (NLP), yet they encounter challenges such as hallucination and the need for domain-specific knowledge. To mitigate these, recent methodologies have integrated information retrieved from external resources with LLMs, substantially enhancing their performance across NLP tasks. This survey paper addresses the absence of a comprehensive overview on Retrieval-Augmented Language Models (RALMs), both Retrieval-Augmented Generation (RAG) and Retrieval-Augmented Understanding (RAU), providing an in-depth examination of their paradigm, evolution, taxonomy, and applications. The paper discusses the essential components of RALMs, including Retrievers, Language Models, and Augmentations, and how their interactions lead to diverse model structures and applications. RALMs demonstrate utility in a spectrum of tasks, from translation and dialogue systems to knowledge-intensive applications. The survey includes several evaluation methods of RALMs, emphasizing the importance of robustness, accuracy, and relevance in their assessment. It also acknowledges the limitations of RALMs, particularly in retrieval quality and computational efficiency, offering directions for future research. In conclusion, this survey aims to offer a structured insight into RALMs, their potential, and the avenues for their future development in NLP. The paper is supplemented with a Github Repository containing the surveyed works and resources for further study: https://github.com/2471023025/RALM_Survey.
Key facts. Cited by 25 papers in the map (data through 14 Oct 2026). Placed in Generation and context integration, one of 15 directions in Retrieval-augmented generation. Builds on 104 of its 133 references that are in the map. First posted on arXiv 30 Apr 2024.
Builds on
104 of 133 references.
Closest ancestors · 13
Same direction, newest first
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- 2023Making Retrieval-Augmented Language Models Robust to Irrelevant Context2 Oct
- 2023RA-DIT: Retrieval-Augmented Dual Instruction Tuning2 Oct
- 2023In-Context Retrieval-Augmented Language Models31 Jan
- 2023REPLUG: Retrieval-Augmented Black-Box Language Models30 Jan
- 2022Demonstrate-Search-Predict: Composing retrieval and language models for knowledge-intensive NLP28 Dec
- 2022When Not to Trust Language Models: Investigating Effectiveness of Parametric and Non-Parametric Memories20 Dec
- 2022Atlas: Few-shot Learning with Retrieval Augmented Language Models5 Aug
- 2022Retrieval-Augmented Multilingual Keyphrase Generation with Retriever-Generator Iterative Training21 May
- 2021Robust Retrieval Augmented Generation for Zero-shot Slot Filling31 Aug
- 2020Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks22 May
1 more
Other references · 91
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- 2015Deep Residual Learning for Image Recognitioncited by 52,096
- 2018BERT: Pre-training of Deep Bidirectional Transformers for Language Understandingcited by 40,399
- 2020Language Models are Few-Shot Learnerscited by 32,419
- 2023GPT-4 Technical Reportcited by 18,396
- 2019Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformercited by 14,599
- 2023LLaMA: Open and Efficient Foundation Language Modelscited by 14,132
- 2019RoBERTa: A Robustly Optimized BERT Pretraining Approachcited by 13,372
- 2022Hierarchical Text-Conditional Image Generation with CLIP Latentscited by 6,585
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- 2021RoFormer: Enhanced Transformer with Rotary Position Embeddingcited by 4,703
- 2019DistilBERT, a distilled version of BERT: smaller, faster, cheaper and lightercited by 4,307
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- 2023Self-RAG: Learning to Retrieve, Generate, and Critique through Self-Reflectioncited by 1,839
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- 2019Generating Long Sequences with Sparse Transformerscited by 1,546
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- 2021ColBERTv2: Effective and Efficient Retrieval via Lightweight Late Interactioncited by 476
- 2021Large Dual Encoders Are Generalizable Retrieverscited by 456
- 2024Retrieval-Augmented Generation for AI-Generated Content: A Surveycited by 354
- 2023Check Your Facts and Try Again: Improving Large Language Models with External Knowledge and Automated Feedbackcited by 353
- 2023Enhancing Retrieval-Augmented Large Language Models with Iterative Retrieval-Generation Synergycited by 346
- 2024Benchmarking Retrieval-Augmented Generation for Medicinecited by 331
- 2023Make-An-Audio: Text-To-Audio Generation with Prompt-Enhanced Diffusion Modelscited by 324
- 2021Few-shot Learning with Multilingual Language Modelscited by 278
- 2024ReEvo: Large Language Models as Hyper-Heuristics with Reflective Evolutioncited by 276
- 2023ARES: An Automated Evaluation Framework for Retrieval-Augmented Generation Systemscited by 265
- 2023Using an LLM to Help With Code Understandingcited by 228
- 2020Distilling Knowledge from Reader to Retriever for Question Answeringcited by 226
- 2022MuRAG: Multimodal Retrieval-Augmented Generator for Open Question Answering over Images and Textcited by 220
- 2021Internet-Augmented Dialogue Generationcited by 217
- 2022Re-Imagen: Retrieval-Augmented Text-to-Image Generatorcited by 210
50 most cited of 91 All 91 (JSON)
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Citing papers per year: 2024: 9; 2025: 10; 2026: 6.
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- 2024Modular RAG: Transforming RAG Systems into LEGO-like Reconfigurable Frameworkscited by 42
- 2024Agent Design Pattern Catalogue: A Collection of Architectural Patterns for Foundation Model based Agentscited by 35
- 2025Retrieval Augmented Generation and Understanding in Vision: A Survey and New Outlookcited by 32
- 2024Surveying the MLLM Landscape: A Meta-Review of Current Surveyscited by 20
- 2024SmartRAG: Jointly Learn RAG-Related Tasks From the Environment Feedbackcited by 19
- 2024Towards Reliable Medical Question Answering: Techniques and Challenges in Mitigating Hallucinations in Language Modelscited by 15
- 2025AdaVideoRAG: Omni-Contextual Adaptive Retrieval-Augmented Efficient Long Video Understandingcited by 15
- 2026SoK: Privacy Risks and Mitigations in Retrieval-Augmented Generation Systemscited by 7
- 2025Biomedical Knowledge Graph: A Survey of Domains, Tasks, and Real-World Applicationscited by 6
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- 2024A Survey of Retrieval Algorithms in Ad and Content Recommendation Systemscited by 5
- 2025DoctorRAG: Medical RAG Fusing Knowledge with Patient Analogy through Textual Gradientscited by 5
13 more
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- 2024A Survey of Query Optimization in Large Language Modelscited by 1
- 2025LEKA:LLM-Enhanced Knowledge Augmentationcited by 1
- 2025SubGCache: Accelerating Graph-based RAG with Subgraph-level KV Cachecited by 1
- 2025ModernBERT + ColBERT: Enhancing biomedical RAG through an advanced re-ranking retrievercited by 1
- 2026GraphSeek: Next-Generation Graph Analytics with LLMscited by 1
- 2024Thorns and Algorithms: Navigating Generative AI Challenges Inspired by Giraffes and Acaciascited by 0
- 2025Smarter, not Bigger: Fine-Tuned RAG-Enhanced LLMs for Automotive HIL Testingcited by 0
- 2026PIER: Physics-Informed Environmental Retrieval for Time-Series Modelingcited by 0
- 2026When Context Misleads: Intent-Guided Decoding for Robust Retrieval-Augmented Generationcited by 0
- 2026NeuroGraph: An AI Graph-Driven Neuro-Symbolic Framework for Explainable Threat Reasoning in Advanced Manufacturingcited by 0
- 2026Mapping the RAG Landscape: A Four Axis Taxonomy of Efficiency, Defense, Interactivity, and Reasoningcited by 0
- 2026Mapping the RAG Landscape: A Four Axis Taxonomy of Efficiency, Defense, Interactivity, and Reasoning1 Oct 2026
- 2026NeuroGraph: An AI Graph-Driven Neuro-Symbolic Framework for Explainable Threat Reasoning in Advanced Manufacturing1 Sep 2026
- 2026When Context Misleads: Intent-Guided Decoding for Robust Retrieval-Augmented Generation17 Aug 2026
- 2026PIER: Physics-Informed Environmental Retrieval for Time-Series Modeling22 Jul 2026
- 2026GraphSeek: Next-Generation Graph Analytics with LLMs11 Feb 2026
- 2026SoK: Privacy Risks and Mitigations in Retrieval-Augmented Generation Systems7 Jan 2026
- 2025Smarter, not Bigger: Fine-Tuned RAG-Enhanced LLMs for Automotive HIL Testing27 Nov 2025
- 2025ModernBERT + ColBERT: Enhancing biomedical RAG through an advanced re-ranking retriever6 Oct 2025
- 2025AdaVideoRAG: Omni-Contextual Adaptive Retrieval-Augmented Efficient Long Video Understanding16 Jun 2025
- 2025RAGOps: Operating and Managing Retrieval-Augmented Generation Pipelines3 Jun 2025
- 2025DoctorRAG: Medical RAG Fusing Knowledge with Patient Analogy through Textual Gradients26 May 2025
- 2025SubGCache: Accelerating Graph-based RAG with Subgraph-level KV Cache16 May 2025
13 more
- 2025Affordable AI Assistants with Knowledge Graph of Thoughts3 Apr 2025
- 2025Retrieval Augmented Generation and Understanding in Vision: A Survey and New Outlook23 Mar 2025
- 2025LEKA:LLM-Enhanced Knowledge Augmentation29 Jan 2025
- 2025Biomedical Knowledge Graph: A Survey of Domains, Tasks, and Real-World Applications20 Jan 2025
- 2024A Survey of Query Optimization in Large Language Models23 Dec 2024
- 2024SmartRAG: Jointly Learn RAG-Related Tasks From the Environment Feedback22 Oct 2024
- 2024Surveying the MLLM Landscape: A Meta-Review of Current Surveys17 Sep 2024
- 2024Towards Reliable Medical Question Answering: Techniques and Challenges in Mitigating Hallucinations in Language Models25 Aug 2024
- 2024Modular RAG: Transforming RAG Systems into LEGO-like Reconfigurable Frameworks26 Jul 2024
- 2024Thorns and Algorithms: Navigating Generative AI Challenges Inspired by Giraffes and Acacias16 Jul 2024
- 2024A Survey of Retrieval Algorithms in Ad and Content Recommendation Systems21 Jun 2024
- 2024Retrieval-Augmented Feature Generation for Domain-Specific Classification17 Jun 2024
- 2024Agent Design Pattern Catalogue: A Collection of Architectural Patterns for Foundation Model based Agents16 May 2024
- 2024Modular RAG: Transforming RAG Systems into LEGO-like Reconfigurable Frameworkscited by 42
- 2025Retrieval Augmented Generation and Understanding in Vision: A Survey and New Outlookcited by 32
- 2024SmartRAG: Jointly Learn RAG-Related Tasks From the Environment Feedbackcited by 19
- 2026SoK: Privacy Risks and Mitigations in Retrieval-Augmented Generation Systemscited by 7
- 2025DoctorRAG: Medical RAG Fusing Knowledge with Patient Analogy through Textual Gradientscited by 5
- 2025RAGOps: Operating and Managing Retrieval-Augmented Generation Pipelinescited by 5
- 2024Retrieval-Augmented Feature Generation for Domain-Specific Classificationcited by 3
- 2024A Survey of Query Optimization in Large Language Modelscited by 1
- 2025SubGCache: Accelerating Graph-based RAG with Subgraph-level KV Cachecited by 1
- 2025ModernBERT + ColBERT: Enhancing biomedical RAG through an advanced re-ranking retrievercited by 1
- 2026When Context Misleads: Intent-Guided Decoding for Robust Retrieval-Augmented Generationcited by 0
- 2026When Context Misleads: Intent-Guided Decoding for Robust Retrieval-Augmented Generation17 Aug 2026
- 2026SoK: Privacy Risks and Mitigations in Retrieval-Augmented Generation Systems7 Jan 2026
- 2025ModernBERT + ColBERT: Enhancing biomedical RAG through an advanced re-ranking retriever6 Oct 2025
- 2025RAGOps: Operating and Managing Retrieval-Augmented Generation Pipelines3 Jun 2025
- 2025DoctorRAG: Medical RAG Fusing Knowledge with Patient Analogy through Textual Gradients26 May 2025
- 2025SubGCache: Accelerating Graph-based RAG with Subgraph-level KV Cache16 May 2025
- 2025Retrieval Augmented Generation and Understanding in Vision: A Survey and New Outlook23 Mar 2025
- 2024A Survey of Query Optimization in Large Language Models23 Dec 2024
- 2024SmartRAG: Jointly Learn RAG-Related Tasks From the Environment Feedback22 Oct 2024
- 2024Modular RAG: Transforming RAG Systems into LEGO-like Reconfigurable Frameworks26 Jul 2024
- 2024Retrieval-Augmented Feature Generation for Domain-Specific Classification17 Jun 2024
- 2025Affordable AI Assistants with Knowledge Graph of Thoughtscited by 6
- 2026NeuroGraph: An AI Graph-Driven Neuro-Symbolic Framework for Explainable Threat Reasoning in Advanced Manufacturingcited by 0
- 2026Mapping the RAG Landscape: A Four Axis Taxonomy of Efficiency, Defense, Interactivity, and Reasoningcited by 0
- 2026Mapping the RAG Landscape: A Four Axis Taxonomy of Efficiency, Defense, Interactivity, and Reasoning1 Oct 2026
- 2026NeuroGraph: An AI Graph-Driven Neuro-Symbolic Framework for Explainable Threat Reasoning in Advanced Manufacturing1 Sep 2026
- 2025Affordable AI Assistants with Knowledge Graph of Thoughts3 Apr 2025
- 2024Towards Reliable Medical Question Answering: Techniques and Challenges in Mitigating Hallucinations in Language Modelscited by 15
- 2025Biomedical Knowledge Graph: A Survey of Domains, Tasks, and Real-World Applicationscited by 6
- 2024A Survey of Retrieval Algorithms in Ad and Content Recommendation Systemscited by 5
- 2025LEKA:LLM-Enhanced Knowledge Augmentationcited by 1
- 2026GraphSeek: Next-Generation Graph Analytics with LLMscited by 1
- 2024Thorns and Algorithms: Navigating Generative AI Challenges Inspired by Giraffes and Acaciascited by 0
- 2025Smarter, not Bigger: Fine-Tuned RAG-Enhanced LLMs for Automotive HIL Testingcited by 0
- 2026PIER: Physics-Informed Environmental Retrieval for Time-Series Modelingcited by 0
- 2026PIER: Physics-Informed Environmental Retrieval for Time-Series Modeling22 Jul 2026
- 2026GraphSeek: Next-Generation Graph Analytics with LLMs11 Feb 2026
- 2025Smarter, not Bigger: Fine-Tuned RAG-Enhanced LLMs for Automotive HIL Testing27 Nov 2025
- 2025LEKA:LLM-Enhanced Knowledge Augmentation29 Jan 2025
- 2025Biomedical Knowledge Graph: A Survey of Domains, Tasks, and Real-World Applications20 Jan 2025
- 2024Towards Reliable Medical Question Answering: Techniques and Challenges in Mitigating Hallucinations in Language Models25 Aug 2024
- 2024Thorns and Algorithms: Navigating Generative AI Challenges Inspired by Giraffes and Acacias16 Jul 2024
- 2024A Survey of Retrieval Algorithms in Ad and Content Recommendation Systems21 Jun 2024
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