Core Concepts
The team developed a prompt-based solution using GPT4 to reason over legal arguments, exploring an ensemble of prompting strategies including chain-of-thought reasoning and in-context learning.
Abstract
The paper presents the system developed by Team UTSA-NLP for the SemEval 2024 Task 5, The Legal Argument Reasoning Task in Civil Procedure Challenge. The task involves determining the validity of an answer candidate given case law context.
The key highlights and insights are:
The team explored three major prompting approaches: zero-shot prompting, few-shot prompting, and few-shot prompting with chain-of-thought-like reasoning. They also experimented with an ensemble of these methods.
The few-shot prompting approach combined in-context learning and chain-of-thought reasoning, using a retrieval-based system to find relevant examples for each test case. This method achieved the best individual performance.
The ensemble approach, which combined multiple prompting variants, resulted in the highest Macro F1 score of 0.8095 on the validation dataset.
Error analysis revealed limitations of the GPT4-based system, such as struggles with identifying correct answers but flawed reasoning, and issues with long introductions that distract from the key context.
The team discussed potential future research directions, including exploring step-by-step reasoning in the Analysis section, using more in-context examples, and evaluating open-source language models.
Overall, the paper demonstrates the effectiveness of prompt-based strategies, particularly ensemble methods, for legal reasoning tasks, while also highlighting areas for improvement in handling complex legal contexts.
Stats
"A class action lawsuit involves a legal action where a group of people collectively bring a claim to court or in which a class of defendants is being sued."
"In a breach of contract case, the plaintiff (Mark) generally needs to demonstrate that they suffered financial damages as a result of the breach. Proving financial harm is a common requirement in such cases."
Quotes
"Mastering the reasoning behind legal arguments is a fundamental skill required of all law students."
"There has been substantial research in developing NLP-based reasoning systems."