Two-step cascaded textual entailment for legal bar exam question answering
Full Text: 3086512.3086550.pdf
Our legal question answering system combines legal information retrieval and textual entailment, and exploits semantic information using a logic-based representation. We have evaluated our system using the data from the competition on legal information extraction/entailment (COLIEE)-2017. The competition focuses on the legal information processing required to answer yes/no questions from Japanese legal bar exams, and it consists of two phases: ad hoc legal information retrieval (Phase 1), and textual entailment (Phase 2). Phase 1 requires the identification of Japan civil law articles relevant to a legal bar exam query. For this phase, we have used an information retrieval approach using TF-IDF combined with a simple language model. Phase 2 requires a yes/no decision for previously unseen queries, which we approach by comparing the approximate meanings of queries with relevant statutes. Our meaning extraction process uses a selection of features based on a kind of paraphrase, coupled with a condition/conclusion/exception analysis of articles and queries. We also extract and exploit negation patterns from the articles. We construct a logic-based representation as a semantic analysis result, and then classify questions into easy and difficult types by analyzing the logic representation. If a question is in our easy category, we simply obtain the entailment answer from the logic representation; otherwise we use an unsupervised learning method to obtain the entailment answer. Experimental evaluation shows that our result ranked highest in the Phase 2 amongst all COLIEE-2017 competitors.
Citation
M. Kim, R. Goebel. "Two-step cascaded textual entailment for legal bar exam question answering". International Conference on Artificial Intelligence and Law (ICAIL), pp 283-290, June 2017.| Keywords: | |
| Category: | In Conference |
| Web Links: | ACM Digital Library |
BibTeX
@incollection{Kim+Goebel:(ICAIL)17,
author = {Mi-Young Kim and Randy Goebel},
title = {Two-step cascaded textual entailment for legal bar exam question
answering},
Pages = {283-290},
booktitle = {International Conference on Artificial Intelligence and Law
(ICAIL)},
year = 2017,
}Last Updated: June 09, 2020Submitted by Sabina P
