Knowledge-Infused Legal Wisdom: Navigating LLM Consultation through the Lens of Diagnostics and Positive-Unlabeled Reinforcement Learning
Yang Wu, Chenghao Wang, Ece Gumusel, Xiaozhong Liu
TL;DR
The paper addresses the challenge that non-experts struggle to formulate professional queries to LLMs in legal contexts, proposing the Diagnostic Legal LLM (D3LM) which uses lawyer-like diagnostics to collect rich case information and generate high-quality court views. It introduces a Positive-Unlabeled Reinforcement Learning (PURL) framework that fuses domain PU models with LLMs for adaptive question generation, along with an LLM-based stopping criterion for precise CVG. A new English-language US CVG dataset is created to benchmark performance, including IRAC-based summaries and fact-rule graphs. Empirical results show that D3LM achieves superior automatic and human-evaluated performance compared to baselines, and usability studies indicate strong user acceptance, highlighting its potential to improve accuracy and reduce legal service costs. Limitations include domain specificity to criminal law, English-only scope, and high resource requirements, with future work aimed at cross-domain generalization, multilingual support, and efficiency optimization.
Abstract
The integration of generative Large Language Models (LLMs) into various applications, including the legal domain, has been accelerated by their expansive and versatile nature. However, when facing a legal case, users without a legal background often struggle to formulate professional queries and may inadvertently overlook critical legal factors when presenting their case narrative to LLMs. To address this issue, we propose the Diagnostic Legal Large Language Model (D3LM), which utilizes adaptive lawyer-like diagnostic questions to collect additional case information and then provides high-quality feedback. D3LM incorporates an innovative graph-based Positive-Unlabeled Reinforcement Learning (PURL) algorithm, enabling the generation of critical questions and enhancing user-LLM interactions. Moreover, an integrated LLM-based stopping criterion facilitates precise Court Views Generation (CVG). Our research also introduces a new English-language CVG dataset based on the US case law database, enriching the realm of LLM research and deployment with a vital dimension. D3LM surpasses classical LLMs by delivering outstanding performance and a remarkable user experience in the legal domain.
