Abstract
Complex question answering often requires finding a reasoning chain that consists of multiple evidence pieces. Current approaches incorporate the strengths of structured knowledge and unstructured text, assuming text corpora is semi-structured. Building on dense retrieval methods, we propose a new multi-step retrieval approach (BeamDR) that iteratively forms an evidence chain through beam search in dense representations. When evaluated on multi-hop question answering, BeamDR is competitive to state-of-the-art systems, without using any semi-structured information. Through query composition in dense space, BeamDR captures the implicit relationships between evidence in the reasoning chain. The code is available at https://github.com/henryzhao5852/BeamDR.- Anthology ID:
- 2021.naacl-main.368
- Volume:
- Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies
- Month:
- June
- Year:
- 2021
- Address:
- Online
- Editors:
- Kristina Toutanova, Anna Rumshisky, Luke Zettlemoyer, Dilek Hakkani-Tur, Iz Beltagy, Steven Bethard, Ryan Cotterell, Tanmoy Chakraborty, Yichao Zhou
- Venue:
- NAACL
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 4635–4641
- Language:
- URL:
- https://preview.aclanthology.org/build-pipeline-with-new-library/2021.naacl-main.368/
- DOI:
- 10.18653/v1/2021.naacl-main.368
- Cite (ACL):
- Chen Zhao, Chenyan Xiong, Jordan Boyd-Graber, and Hal Daumé III. 2021. Multi-Step Reasoning Over Unstructured Text with Beam Dense Retrieval. In Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, pages 4635–4641, Online. Association for Computational Linguistics.
- Cite (Informal):
- Multi-Step Reasoning Over Unstructured Text with Beam Dense Retrieval (Zhao et al., NAACL 2021)
- PDF:
- https://preview.aclanthology.org/build-pipeline-with-new-library/2021.naacl-main.368.pdf
- Code
- henryzhao5852/BeamDR