Leveraging Passage Retrieval with Generative Models for Open Domain Question Answering
Written for the Research library (claude-opus-5-5) from the paper text. Original — aclanthology.org/2021.eacl-main.74.pdf
Summary
Open-domain question answering means answering factual questions when the system is not given the text that contains the answer. A closed-book generative approach (T5) stores all its knowledge in model weights, so it needs billions of parameters and is costly to train and run. This paper pairs retrieval with a generative reader. First, BM25 or DPR fetches supporting Wikipedia passages. Then a pretrained T5 model reads them. The encoder handles each passage separately, together with its title and the question. The decoder attends over the joined encodings of all passages, a design the authors call Fusion-in-Decoder. Because the encoder looks at one passage at a time, cost grows linearly with the number of passages, so the reader can take in 100 of them. The authors scored the model with exact match on open versions of NaturalQuestions, TriviaQA and SQuAD v1.1. It got the best published scores on the first two, and accuracy kept rising as more passages were added. This suggests that generative readers are good at combining evidence spread across many documents.
Key points
- Architecture: Fusion-in-Decoder is built on T5 base (220M parameters) and T5 large (770M). Its inputs are tagged with the special tokens
question:,title:andcontext:. The model reads 100 retrieved passages, each cut to 250 word pieces. DPR is the retriever for NQ and TriviaQA, and BM25 is used for SQuAD. - Large model, exact match: 51.4 on NaturalQuestions, 67.6 on open TriviaQA (80.1 on the hidden test set) and 56.7 on SQuAD Open (F1 63.2). These scores beat REALM, DPR, RAG, SpanSeqGen and GPT-3 few-shot.
- Retrieval vs. size: With 770M parameters plus BM25 retrieval over Wikipedia, the model reaches 44.1% on NQ. The 11B closed-book T5 scores 36.6%, while storing roughly the same amount of information.
- More passages help: Going from 10 to 100 retrieved passages adds about 6 points on TriviaQA and 3.5 on NQ. Extractive readers usually stop improving at around 10–20 passages.
- Setup: Wikipedia dumps from December 2018 (NQ, TriviaQA) and December 2016 (SQuAD) were split into non-overlapping 100-word passages. Training used 64 V100 GPUs for 10k steps with batch size 64.
Cited by
- Benchmarking Large Language Models in Retrieval-Augmented Generation
- Adapting Language Models to Compress Contexts
- A Survey on RAG Meeting LLMs: Towards Retrieval-Augmented Large Language Models
- Enabling Large Language Models to Generate Text with Citations
- LongT5: Efficient Text-To-Text Transformer for Long Sequences
- Unsupervised Dense Information Retrieval with Contrastive Learning
- Adaptive-RAG: Learning to Adapt Retrieval-Augmented Large Language Models through Question Complexity
- LLM-Blender: Ensembling Large Language Models with Pairwise Ranking and Generative Fusion
- Dense Passage Retrieval for Open-Domain Question Answering
- RealTime QA: What's the Answer Right Now?
- Demonstrate-Search-Predict: Composing retrieval and language models for knowledge-intensive NLP
- Internet-Augmented Dialogue Generation
- Hurdles to Progress in Long-form Question Answering
- Internet-augmented language models through few-shot prompting for open-domain question answering
- PAQ: 65 Million Probably-Asked Questions and What You Can Do With Them
- RA-DIT: Retrieval-Augmented Dual Instruction Tuning
- Lost in the Middle: How Language Models Use Long Contexts
- Entity-Based Knowledge Conflicts in Question Answering
- Generation-Augmented Retrieval for Open-domain Question Answering
- Teaching language models to support answers with verified quotes
- Augmented Language Models: a Survey
- PragmatiCQA: A Dataset for Pragmatic Question Answering in Conversations
- RocketQA: An Optimized Training Approach to Dense Passage Retrieval for Open-Domain Question Answering
- Improving Passage Retrieval with Zero-Shot Question Generation
- LaMP: When Large Language Models Meet Personalization
- Enhancing Retrieval-Augmented Large Language Models with Iterative Retrieval-Generation Synergy
- REPLUG: Retrieval-Augmented Black-Box Language Models
- Retrieval Augmentation Reduces Hallucination in Conversation
- BlenderBot 3: a deployed conversational agent that continually learns to responsibly engage
- Beyond the Imitation Game: Quantifying and extrapolating the capabilities of language models
- ASQA: Factoid Questions Meet Long-Form Answers
- One Embedder, Any Task: Instruction-Finetuned Text Embeddings
- LaMDA: Language Models for Dialog Applications
- Survey on Factuality in Large Language Models: Knowledge, Retrieval and Domain-Specificity
- Adaptive Chameleon or Stubborn Sloth: Revealing the Behavior of Large Language Models in Knowledge Conflicts
- Retrieval meets Long Context Large Language Models
- LeanDojo: Theorem Proving with Retrieval-Augmented Language Models
- Generate rather than Retrieve: Large Language Models are Strong Context Generators
- CREPE: Open-Domain Question Answering with False Presuppositions
- IfQA: A Dataset for Open-domain Question Answering under Counterfactual Presuppositions
- Big Bird: Transformers for Longer Sequences
- A Survey of Large Language Models
Cite
@inproceedings{izacard2021leveraging,
title = {{Leveraging Passage Retrieval with Generative Models for Open Domain Question Answering}},
author = {Izacard, Gautier and Grave, Edouard},
booktitle = {Proceedings of the 16th Conference of the European Chapter of the Association for Computational Linguistics: Main Volume},
year = {2021},
doi = {10.18653/v1/2021.eacl-main.74},
eprint = {2007.01282},
archivePrefix = {arXiv},
url = {https://doi.org/10.18653/v1/2021.eacl-main.74}
}References
- number of retrieved passages. In particular, we observe that increasing the number of passages from 10 to 100 leads to 6% improvement on TriviaQA and 3.5% improvement on NaturalQuestions. On the other hand, the performance of most extractive models seems to peak around 10 to 20 passages (Wang et al.… find
- Danqi Chen, Adam Fisch, Jason Weston, and Antoine Bordes. 2017. Reading Wikipedia to answer open-domain questions. In Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics, pages 1870–1879. \#\# Conclusion In this paper, we study a simple approach to open domain quest… find our card
- Akari Asai, Kazuma Hashimoto, Hannaneh Hajishirzi, Richard Socher, and Caiming Xiong. 2020. Learning to retrieve reasoning paths over wikipedia graph for question answering. In International Conference on Learning Representations. find our card
- Tom B Brown, Benjamin Mann, Nick Ryder, Melanie Subbiah, Jared Kaplan, Prafulla Dhariwal, Arvind Neelakantan, Pranav Shyam, Girish Sastry, Amanda Askell, et al. 2020. Language models are few-shot learners. arXiv preprint arXiv:2005.14165. find
- Christopher Clark and Matt Gardner. 2018. Simple and effective multi-paragraph reading comprehension. In Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics, pages 845–855. find our card
- Jacob Devlin, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova. 2019. BERT: Pre-training of deep bidirectional transformers for language understanding. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies,… find
- Angela Fan, Yacine Jernite, Ethan Perez, David Grangier, Jason Weston, and Michael Auli. 2019. ELI5: Long form question answering. In Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics, pages 3558–3567. find our card
- Kelvin Guu, Kenton Lee, Zora Tung, Panupong Pasupat, and Ming-Wei Chang. 2020. Realm: Retrieval-augmented language model pre-training. arXiv preprint arXiv:2002.08909. find
- Zhengbao Jiang, Frank F. Xu, Jun Araki, and Graham Neubig. 2019. How can we know what language models know? arXiv preprint arXiv:1911.12543. find our card
- Mandar Joshi, Eunsol Choi, Daniel S. Weld, and Luke Zettlemoyer. 2017. Triviaqa: A large scale distantly supervised challenge dataset for reading comprehension. In Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics, pages 1601–1611. find our card
- Vladimir Karpukhin, Barlas Oğuz, Sewon Min, Ledell Wu, Sergey Edunov, Danqi Chen, and Wen-tau Yih. 2020. Dense passage retrieval for open-domain question answering. arXiv preprint arXiv:2004.04906. find our card
- Diederik P. Kingma and Jimmy Ba. 2014. Adam: A method for stochastic optimization. arXiv preprint arXiv:1412.6980. find
- Tomáš Kočiskỳ, Jonathan Schwarz, Phil Blunsom, Chris Dyer, Karl Moritz Hermann, Gábor Melis, and Edward Grefenstette. 2018. The NarrativeQA reading comprehension challenge. Transactions of the Association for Computational Linguistics, 6:317– 328. find our card
- Tom Kwiatkowski, Jennimaria Palomaki, Olivia Red-field, Michael Collins, Ankur Parikh, Chris Alberti, Danielle Epstein, Illia Polosukhin, Matthew Kelcey, Jacob Devlin, Kenton Lee, Kristina N. Toutanova, Llion Jones, Ming-Wei Chang, Andrew Dai, Jakob Uszkoreit, Quoc Le, and Slav Petrov. 2019. Natural… find our card
- Jinhyuk Lee, Seongjun Yun, Hyunjae Kim, Miyoung Ko, and Jaewoo Kang. 2018. Ranking paragraphs for improving answer recall in open-domain question answering. In Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing, pages 565–569. find
- Kenton Lee, Ming-Wei Chang, and Kristina Toutanova. 2019. Latent retrieval for weakly supervised open domain question answering. In Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics, pages 6086–6096. find our card
- Mike Lewis, Yinhan Liu, Naman Goyal, Marjan Ghazvininejad, Abdelrahman Mohamed, Omer Levy, Veselin Stoyanov, and Luke Zettlemoyer. 2020a. BART: Denoising sequence-to-sequence pre-training for natural language generation, translation, and comprehension. In Proceedings of the 58th Annual Meeting of th… find our card
- Patrick Lewis, Ethan Perez, Aleksandara Piktus, Fabio Petroni, Vladimir Karpukhin, Naman Goyal, Heinrich Küttler, Mike Lewis, Wen-tau Yih, Tim Rocktäschel, et al. 2020b. Retrieval-augmented generation for knowledge-intensive nlp tasks. arXiv preprint arXiv:2005.11401. find
- Sewon Min, Danqi Chen, Hannaneh Hajishirzi, and Luke Zettlemoyer. 2019a. A discrete hard EM approach for weakly supervised question answering. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Proc… find
- Sewon Min, Danqi Chen, Luke Zettlemoyer, and Hannaneh Hajishirzi. 2019b. Knowledge guided text retrieval and reading for open domain question answering. arXiv preprint arXiv:1911.03868. find
- Sewon Min, Julian Michael, Hannaneh Hajishirzi, and Luke Zettlemoyer. 2020. AmbigQA: Answering ambiguous open-domain questions. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing, pages 5783–5797. find
- Matthew Peters, Mark Neumann, Mohit Iyyer, Matt Gardner, Christopher Clark, Kenton Lee, and Luke Zettlemoyer. 2018. Deep contextualized word representations. In Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technolog… find
- Fabio Petroni, Tim Rocktäschel, Sebastian Riedel, Patrick Lewis, Anton Bakhtin, Yuxiang Wu, and Alexander Miller. 2019. Language models as knowledge bases? In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural… find our card
- Alec Radford, Jeffrey Wu, Rewon Child, David Luan, Dario Amodei, and Ilya Sutskever. 2019. Language models are unsupervised multitask learners. OpenAI Technical Report. find
- Colin Raffel, Noam Shazeer, Adam Roberts, Katherine Lee, Sharan Narang, Michael Matena, Yanqi Zhou, Wei Li, and Peter J. Liu. 2020. Exploring the limits of transfer learning with a unified text-to-text transformer. Journal of Machine Learning Research, 21(140):1–67. find
- Pranav Rajpurkar, Jian Zhang, Konstantin Lopyrev, and Percy Liang. 2016. SQuAD: 100,000+ questions for machine comprehension of text. In Proceedings of the 2016 Conference on Empirical Methods in Natural Language Processing, pages 2383–2392. find our card
- Siva Reddy, Danqi Chen, and Christopher D Manning. 2019. CoQA: A conversational question answering challenge. Transactions of the Association for Computational Linguistics, 7:249–266. find our card
- Adam Roberts, Colin Raffel, and Noam Shazeer. 2020. How much knowledge can you pack into the parameters of a language model? In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing, pages 5418–5426. find
- Stephen E Robertson, Steve Walker, Susan Jones, Micheline M Hancock-Beaulieu, and Mike Gatford. 1995. Okapi at TREC-3. NIST Special Publication Sp. find our card
- Alon Talmor, Yanai Elazar, Yoav Goldberg, and Jonathan Berant. 2019. oLMpics – on what language model pre-training captures. arXiv preprint arXiv:1912.13283. find our card
- Ellen M Voorhees. 1999. The TREC-8 question answering track report. In Proceedings of the Eighth Text REtrieval Conference. find
- Shuohang Wang, Mo Yu, Xiaoxiao Guo, Zhiguo Wang, Tim Klinger, Wei Zhang, Shiyu Chang, Gerry Tesauro, Bowen Zhou, and Jing Jiang. 2018a. R 3 : Reinforced ranker-reader for open-domain question answering. In Proceedings of the 32nd AAAI Conference on Artificial Intelligence. find
- Shuohang Wang, Mo Yu, Jing Jiang, Wei Zhang, Xiaoxiao Guo, Shiyu Chang, Zhiguo Wang, Tim Klinger, Gerald Tesauro, and Murray Campbell. 2018b. Evidence aggregation for answer re-ranking in open-domain question answering. In International Conference on Learning Representations. find
- Zhiguo Wang, Patrick Ng, Xiaofei Ma, Ramesh Nallapati, and Bing Xiang. 2019. Multi-passage BERT: A globally normalized BERT model for open-domain question answering. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference o… find
- Wei Yang, Yuqing Xie, Aileen Lin, Xingyu Li, Luchen Tan, Kun Xiong, Ming Li, and Jimmy Lin. 2019. End-to-end open-domain question answering with BERTserini. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics (Demonstrations), pages 72… find our card