Abstract
The task of answer retrieval in the legal domain aims to help users to seek relevant legal advice from massive amounts of professional responses. Two main challenges hinder applying existing answer retrieval approaches in other domains to the legal domain: (1) a huge knowledge gap between lawyers and non-professionals; and (2) a mix of informal and formal content on legal QA websites. To tackle these challenges, we propose CEFS, a novel cross-encoder (CE) re-ranker based on the fine-grained structured inputs. CEFS uses additional structured information in the CQA data to improve the effectiveness of cross-encoder re-rankers. Furthermore, we propose LegalQA: a real-world benchmark dataset for evaluating answer retrieval in the legal domain. Experiments conducted on LegalQA show that our proposed method significantly outperforms strong cross-encoder re-rankers fine-tuned on MS MARCO. Our novel finding is that adding the question tags of each question besides the question description and title into the input of cross-encoder re-rankers structurally boosts the rankers’ effectiveness. While we study our proposed method in the legal domain, we believe that our method can be applied in similar applications in other domains.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
Notes
- 1.
We interchangeably use the word answer and response to refer to the content written by the professional lawyer.
- 2.
- 3.
We refer to the person who posts a question as a user or questioner throughout this paper.
- 4.
- 5.
- 6.
We use the implementation available at https://github.com/seatgeek/thefuzz.
References
Abolghasemi, A., Verberne, S., Azzopardi, L.: Improving BERT-based query-by-document retrieval with multi-task optimization. In: Hagen, M., et al. (eds.) ECIR 2022. LNCS, vol. 13186, pp. 3–12. Springer, Cham (2022). https://doi.org/10.1007/978-3-030-99739-7_1
Askari, A., Abolghasemi, A., Aliannejadi, M., Kanoulas, E., Verberne, S.: Closer: conversational legal longformer with expertise-aware passage response ranker for long contexts. In: The 32nd ACM International Conference on Information and Knowledge Management (CIKM 2023). ACM (2023)
Askari, A., Abolghasemi, A., Pasi, G., Kraaij, W., Verberne, S.: Injecting the BM25 score as text improves BERT-based re-rankers. In: Advances in Information Retrieval, pp. 66–83. Springer Nature Switzerland, Cham (2023). https://doi.org/10.1007/978-3-031-28244-7_5
Askari, A., Verberne, S., Pasi, G.: Expert finding in legal community question answering. In: Hagen, M., et al. (eds.) Advances in Information Retrieval, pp. 22–30. Springer International Publishing, Cham (2022). https://doi.org/10.1007/978-3-030-99739-7_3
Atkinson, J., Figueroa, A., Andrade, C.: Evolutionary optimization for ranking how-to questions based on user-generated contents. Expert Syst. Appl. 40(17), 7060–7068 (2013)
Bian, J., Liu, Y., Agichtein, E., Zha, H.: Finding the right facts in the crowd: factoid question answering over social media. In: Proceedings of the 17th International Conference on World Wide Web, pp. 467–476 (2008)
Boualili, L., Moreno, J.G., Boughanem, M.: MarkedBERT: integrating traditional IR cues in pre-trained language models for passage retrieval. In: Proceedings of the 43rd International ACM SIGIR Conference on Research and Development in Information Retrieval, pp. 1977–1980 (2020)
Budler, L.C., Gosak, L., Stiglic, G.: Review of artificial intelligence-based question-answering systems in healthcare. Wiley Interdisc. Rev.: Data Min. Knowl. Disc. 13(2), e1487 (2023)
Chen, T., Zhang, M., Lu, J., Bendersky, M., Najork, M.: Out-of-domain semantics to the rescue! zero-shot hybrid retrieval models. In: Hagen, M., et al. (eds.) ECIR 2022. LNCS, vol. 13185, pp. 95–110. Springer, Cham (2022). https://doi.org/10.1007/978-3-030-99736-6_7
Haigh, R.: Legal English. Routledge (2018)
Han, J., Hong, T., Kim, B., Ko, Y., Seo, J.: Fine-grained post-training for improving retrieval-based dialogue systems. In: Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, pp. 1549–1558 (2021)
Hofstätter, S., Althammer, S., Schröder, M., Sertkan, M., Hanbury, A.: Improving efficient neural ranking models with cross-architecture knowledge distillation. arXiv preprint arXiv:2010.02666 (2020)
Kingma, D.P., Ba, J.: Adam: a method for stochastic optimization. arXiv preprint arXiv:1412.6980 (2014)
Levenshtein, V.: Binary codes capable of correcting deletions, insertions and reversals. In: Soviet Physics-Doklady, vol. 10, pp. 707–710 (1966)
Mansouri, B., Campos, R.: FALQU: finding answers to legal questions. arXiv preprint arXiv:2304.05611 (2023)
Martinez-Gil, J.: A survey on legal question-answering systems. Comput. Sci. Rev. 48, 100552 (2023)
Nguyen, T., et al.: Ms MARCO: a human generated machine reading comprehension dataset. In: CoCo@ NIPs (2016)
Nogueira, R., Cho, K.: Passage re-ranking with BERT. arXiv preprint arXiv:1901.04085 (2019)
Ponte, J.M., Croft, W.B.: A language modeling approach to information retrieval. In: ACM SIGIR Forum, vol. 51, pp. 202–208. ACM New York, NY, USA (2017)
Rau, D., Kamps, J.: The role of complex NLP in transformers for text ranking. In: Proceedings of the 2022 ACM SIGIR International Conference on Theory of Information Retrieval, pp. 153–160 (2022)
Robertson, S.E., Walker, S.: Some simple effective approximations to the 2-poisson model for probabilistic weighted retrieval. In: SIGIR’94, pp. 232–241. Springer, London (1994). https://doi.org/10.1007/978-1-4471-2099-5_24
Roy, P.K., Ahmad, Z., Singh, J.P., Alryalat, M.A.A., Rana, N.P., Dwivedi, Y.K.: Finding and ranking high-quality answers in community question answering sites. Glob. J. Flex. Syst. Manag. 19, 53–68 (2018)
Roy, P.K., Saumya, S., Singh, J.P., Banerjee, S., Gutub, A.: Analysis of community question-answering issues via machine learning and deep learning: state-of-the-art review. CAAI Trans. Intell. Technol. 8(1), 95–117 (2023)
Sentence-BERT: cross-encoder for ms MARCO: ms-marco-minilm-l-12-v2 (2023). https://huggingface.co/cross-encoder/ms-marco-MiniLM-L-12-v2
Tiersma, P.M.: Legal language. University of Chicago Press (1999)
Wang, W., Wei, F., Dong, L., Bao, H., Yang, N., Zhou, M.: MiniLM: deep self-attention distillation for task-agnostic compression of pre-trained transformers. Adv. Neural. Inf. Process. Syst. 33, 5776–5788 (2020)
Williams, C.: Tradition and change in legal English: verbal constructions in prescriptive texts, vol. 20. Peter Lang (2007)
Wolf, T., et al.: Huggingface’s transformers: state-of-the-art natural language processing. arXiv preprint arXiv:1910.03771 (2019)
Xiong, W., et al.: TWEETQA: a social media focused question answering dataset. arXiv preprint arXiv:1907.06292 (2019)
Yang, W., et al.: End-to-end open-domain question answering with BERTserini. arXiv preprint arXiv:1902.01718 (2019)
Yen, S.J., Wu, Y.C., Yang, J.C., Lee, Y.S., Lee, C.J., Liu, J.J.: A support vector machine-based context-ranking model for question answering. Inf. Sci. 224, 77–87 (2013)
Zhang, Z., Sabuncu, M.: Generalized cross entropy loss for training deep neural networks with noisy labels. In: Advances in Neural Information Processing Systems, vol. 31 (2018)
Acknowledgments
This work was supported by the EU Horizon 2020 ITN/ETN on Domain Specific Systems for Information Extraction and Retrieval (H2020-EU.1.3.1., ID: 860721).
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2024 The Author(s), under exclusive license to Springer Nature Switzerland AG
About this paper
Cite this paper
Askari, A., Yang, Z., Ren, Z., Verberne, S. (2024). Answer Retrieval in Legal Community Question Answering. In: Goharian, N., et al. Advances in Information Retrieval. ECIR 2024. Lecture Notes in Computer Science, vol 14610. Springer, Cham. https://doi.org/10.1007/978-3-031-56063-7_40
Download citation
DOI: https://doi.org/10.1007/978-3-031-56063-7_40
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-031-56062-0
Online ISBN: 978-3-031-56063-7
eBook Packages: Computer ScienceComputer Science (R0)