arXiv AI
Jun 18

TW-LegalBench: Measuring Taiwanese Legal Understanding

arXiv:2606. 18699v1 Announce Type: cross Abstract: Large language models (LLMs) have shown impressive capabilities across diverse tasks, yet their performance on jurisdiction-specific legal reasoning remains underexplored.

By Fei-Yueh Chen, Chun Huang Lin, Chan Wei Hsu, Kuan Hsuan Yeh, Zih-Ching Chen, Kuan-Ming Chen, Patrick Chung-Chia Huang
arXiv AI
Oct 2

Legal Research Bench: Measuring End-to-End Reliability in Long-Horizon Legal Research Agents

Legal Research Bench (LRB) is a new benchmark comprising 413 open-ended U.S. legal research questions, each paired with a gold answer, supporting authorities, and a binary grading rubric. The study evaluates thirteen advanced language‑model agents using web search, case‑law search, page parsing, and retrieval tools, scoring responses only when all required criteria are met and cited authorities verify. Results show that even the best model, Claude Opus 4.8, achieves full correctness on only 42.9% of questions, with performance varying by legal area and task complexity, and no clear link between more tool calls or inference cost and higher accuracy.

By Katrina Drozdov, Oliver Chen, Langston Nashold, Rayan Krishnan
arXiv AI
6d ago

LexPilot: Benchmarking the Proactive Interaction Ability of Legal LLMs with Laypeople in Chinese Civil Case Consultation

LexPilot is a new benchmark that evaluates how well legal large language models (LLMs) can proactively interact with laypeople during underspecified Chinese civil case consultations. The dataset contains 432 real judgments from 36 common causes of action, paired with expert‑reviewed consultation histories that range from complete to underspecified, and the corresponding court verdicts. Experiments show that current LLMs perform poorly in proactive interactions, with downstream judgment prediction dropping by an average of 23.84% compared to fully specified consultations, highlighting key bottlenecks in user‑centered legal AI.

By Wenbin Zhang, ShangZhan Li, Bingxiang He, Ye He, Yuxin Zhou, Muzhen Cai, Qi Shi, Wanxiang Che
arXiv AI
Oct 5

Do Large Language Models Know Colombian Law? A Reliability Benchmark for the Colombian Legal System

The paper presents an expert‑validated benchmark of 1,042 items across ten areas of Colombian law to assess the reliability of large language models (LLMs) on national legal systems outside the U.S. It evaluates 15 contemporary proprietary and open‑weight models, finding that while closed‑choice accuracy can be high (up to 0.905), free‑text factual correctness never exceeds 0.45. The study reveals a strong dissociation between answer relevance and correctness, systematic variation by legal area, and suggests that expert supervision and grounding in authoritative sources are needed for reliable Colombian legal tasks.

By Rub\'en Manrique, Michelle Castellanos, Jorge Morales, Juan David Guti\'errez, Antonio Barreto Rozo, Joaqu\'in V\'elez Navarro
arXiv Computation and Language
Sep 3

CLASE: A Hybrid Method for Chinese Legalese Stylistic Evaluation

CLASE is a hybrid evaluation method for Chinese legal text that combines linguistic feature-based scores with experience-guided LLM-as-a-judge scores. It learns from contrastive pairs of authentic legal documents and their LLM-generated counterparts, enabling transparent, reference-free assessment of stylistic quality. Experiments on 200 Chinese legal documents show that CLASE aligns better with human judgments than traditional metrics and offers interpretable score breakdowns and improvement suggestions.

By Yiran Rex Ma, Yuxiao Ye, Huiyuan Xie