2 research outputs found
U-CREAT: Unsupervised Case Retrieval using Events extrAcTion
The task of Prior Case Retrieval (PCR) in the legal domain is about
automatically citing relevant (based on facts and precedence) prior legal cases
in a given query case. To further promote research in PCR, in this paper, we
propose a new large benchmark (in English) for the PCR task: IL-PCR (Indian
Legal Prior Case Retrieval) corpus. Given the complex nature of case relevance
and the long size of legal documents, BM25 remains a strong baseline for
ranking the cited prior documents. In this work, we explore the role of events
in legal case retrieval and propose an unsupervised retrieval method-based
pipeline U-CREAT (Unsupervised Case Retrieval using Events Extraction). We find
that the proposed unsupervised retrieval method significantly increases
performance compared to BM25 and makes retrieval faster by a considerable
margin, making it applicable to real-time case retrieval systems. Our proposed
system is generic, we show that it generalizes across two different legal
systems (Indian and Canadian), and it shows state-of-the-art performance on the
benchmarks for both the legal systems (IL-PCR and COLIEE corpora).Comment: Accepted at ACL 2023, 15 pages (12 main + 3 Appendix
SemEval 2023 Task 6: LegalEval -- Understanding Legal Texts
In populous countries, pending legal cases have been growing exponentially.
There is a need for developing NLP-based techniques for processing and
automatically understanding legal documents. To promote research in the area of
Legal NLP we organized the shared task LegalEval - Understanding Legal Texts at
SemEval 2023. LegalEval task has three sub-tasks: Task-A (Rhetorical Roles
Labeling) is about automatically structuring legal documents into semantically
coherent units, Task-B (Legal Named Entity Recognition) deals with identifying
relevant entities in a legal document and Task-C (Court Judgement Prediction
with Explanation) explores the possibility of automatically predicting the
outcome of a legal case along with providing an explanation for the prediction.
In total 26 teams (approx. 100 participants spread across the world) submitted
systems paper. In each of the sub-tasks, the proposed systems outperformed the
baselines; however, there is a lot of scope for improvement. This paper
describes the tasks, and analyzes techniques proposed by various teams.Comment: 13 Pages (9 Pages + References), Accepted at SemEval 202