Understanding Retrieval Augmentation for Long-Form Question Answering
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Abstract (arXiv)
How retrieved documents are used in language models (LMs) for long-form generation task is understudied. We present two controlled studies on retrieval-augmented LM for long-form question answering (LFQA): one fixing the LM and varying evidence documents and the other fixing evidence documents and varying the LMs. We study various attributes of generated answers (e.g., fluency, length, variance), with an emphasis on the attribution of generated answers to in-context evidence documents. We collect a dataset (SALAD) containing human annotations of sentence-level answer attribution in LFQA and evaluate existing methods for automatically judging attribution. We find that while LMs can leverage relevant in-context documents, the generated answer is only partially attributable towards the documents, especially for LMs trained without retrieval augmentation. Together, our analysis reveals how retrieval augmentation impacts long knowledge-rich text generation and provide directions for future work.
Key facts. Cited by 45 papers in the map (data through 7 Oct 2026). Builds on 42 of its 49 references that are in the map. First posted on arXiv 18 Oct 2023.
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42 of 49 references.
References · 42
- 2020Language Models are Few-Shot Learnerscited by 32,199
- 2023LLaMA: Open and Efficient Foundation Language Modelscited by 13,958
- 2016SQuAD: 100,000+ Questions for Machine Comprehension of Textcited by 4,115
- 2023Lost in the Middle: How Language Models Use Long Contextscited by 3,383
- 2022Scaling Instruction-Finetuned Language Modelscited by 2,997
- 2019The Curious Case of Neural Text Degenerationcited by 2,881
- 2017A Broad-Coverage Challenge Corpus for Sentence Understanding through Inferencecited by 2,665
- 2021SimCSE: Simple Contrastive Learning of Sentence Embeddingscited by 2,168
- 2015A large annotated corpus for learning natural language inferencecited by 1,837
- 2021WebGPT: Browser-assisted question-answering with human feedbackcited by 1,722
- 2018FEVER: a large-scale dataset for Fact Extraction and VERificationcited by 1,362
- 2023FActScore: Fine-grained Atomic Evaluation of Factual Precision in Long Form Text Generationcited by 1,259
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- 2023REPLUG: Retrieval-Augmented Black-Box Language Modelscited by 786
- 2023In-Context Retrieval-Augmented Language Modelscited by 694
- 2023Enabling Large Language Models to Generate Text with Citationscited by 584
- 2019ELI5: Long Form Question Answeringcited by 567
- 2018Texygen: A Benchmarking Platform for Text Generation Modelscited by 484
- 2021SummaC: Re-Visiting NLI-based Models for Inconsistency Detection in Summarizationcited by 402
- 2021Entity-Based Knowledge Conflicts in Question Answeringcited by 349
- 2021Do Prompt-Based Models Really Understand the Meaning of their Prompts?cited by 324
- 2023Evaluating Verifiability in Generative Search Enginescited by 297
- 2021Measuring Attribution in Natural Language Generation Modelscited by 253
- 2021QAFactEval: Improved QA-Based Factual Consistency Evaluation for Summarizationcited by 233
- 2022ASQA: Factoid Questions Meet Long-Form Answerscited by 231
- 2021Get Your Vitamin C! Robust Fact Verification with Contrastive Evidencecited by 222
- 2019MRQA 2019 Shared Task: Evaluating Generalization in Reading Comprehensioncited by 183
- 2021Hurdles to Progress in Long-form Question Answeringcited by 166
- 2022Rich Knowledge Sources Bring Complex Knowledge Conflicts: Recalibrating Models to Reflect Conflicting Evidencecited by 142
- 2022Revisiting the Gold Standard: Grounding Summarization Evaluation with Robust Human Evaluationcited by 141
- 2023WiCE: Real-World Entailment for Claims in Wikipediacited by 118
- 2023A Critical Evaluation of Evaluations for Long-form Question Answeringcited by 111
- 2022Attributed Question Answering: Evaluation and Modeling for Attributed Large Language Modelscited by 108
- 2023ExpertQA: Expert-Curated Questions and Attributed Answerscited by 96
- 2023Context-faithful Prompting for Large Language Modelscited by 76
- 2021DocNLI: A Large-scale Dataset for Document-level Natural Language Inferencecited by 75
- 2022RankGen: Improving Text Generation with Large Ranking Modelscited by 72
- 2023Automatic Evaluation of Attribution by Large Language Modelscited by 70
- 2022Stretching Sentence-pair NLI Models to Reason over Long Documents and Clusterscited by 44
- 2023KNN-LM Does Not Improve Open-ended Text Generationcited by 10
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