arXiv Computation and Language

Gavel: Agent Meets Checklist for Evaluating LLMs on Long-Context Legal Summarization

The paper introduces Gavel, a framework for evaluating large language models (LLMs) on long-context legal summarization tasks. Gavel includes a reference-based component (Gavel-Ref) with checklist, residual-fact, and writing-style checks, and a reference-free component (Gavel-Agent) that assesses factual coverage directly from source documents. Experiments on 12 frontier LLMs reveal that models tend to omit key information more than hallucinate, perform well on simple checklist items but struggle with rare, complex items, and their performance degrades with longer cases. Gavel-Agent cuts token usage by at least 36% compared to traditional methods while maintaining competitive accuracy, and it also generalizes effectively to the medical domain.

arXiv AI
Oct 9

When Citations Mislead? A Claim-Level Benchmark for Legal Hallucination Detection

The paper introduces PARCEL, a benchmark designed to evaluate whether legal claims are supported by cited authorities. Using 3,396 claims from New York State Court of Appeals decisions, the authors label each claim as Supported, Refuted, or Not Found and cast the task as a three‑way natural language inference problem. State‑of‑the‑art LLMs achieve up to 0.97 accuracy in zero‑shot settings, yet they still frequently misclassify unsupported claims as supported, especially when fabricated but plausible citations are present.

By M. Mikail Demir, M. Abdullah Canbaz
arXiv Computation and Language
Oct 22

CanLegalRAGBench: Evaluating Retrieval-Augmented Generation on Canadian Case Law

CanLegalRAGBench is a Canadian legal QA benchmark that uses realistic queries and expert‑annotated answers grounded in case law to evaluate retrieval‑augmented generation (RAG) systems. The study finds that retrieval performance varies with design choices and that open‑source embedding models can compete with closed‑source ones. It also highlights limitations of automatic evaluations, noting that RAG systems often produce hallucinations or overly detailed responses, with 8‑29% of claims unsupported by retrieved documents.

By Ethan Zhao, Maksym Taranukhin, Wei Cui, Moira Aikenhead, Vered Shwartz
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 Computation and Language
Sep 11

A Short Survey of Viewing Large Language Models in Legal Aspect

The paper surveys how large language models (LLMs) are being applied in legal tasks such as judgement prediction, document analysis, and drafting. It reviews the benefits of automation while highlighting legal challenges like privacy, bias, and explainability. The authors also discuss data resources for legal domain specialization and outline future research directions.

By Zhongxiang Sun
arXiv Computation and Language
Sep 28

Generating Legal Commentaries from Case Databases via Retrieval, Clustering, and Generation

The paper introduces an automated pipeline that converts court decisions into legal commentaries for specific German Civil Code sections, using paragraph extraction, summarization, keyword clustering, and large language models to generate headings and citation-rich sections. The system processes 4,555 decisions from the German Federal Court of Justice, evaluates the output on relevance, heading match, citation faithfulness, cluster distinction, and logical ordering, and demonstrates that rapid, low-cost commentary generation is feasible while noting limitations due to source restrictions and legal reasoning norms.

By Max Prior, Niklas Wais, Matthias Grabmair
arXiv Computation and Language
Oct 12

OARelatedWork: A Large-Scale Dataset of Related Work Sections with Full-texts from Open Access Sources

OARelatedWork is a large‑scale dataset for generating entire related‑work sections from open‑access papers, comprising 94,450 papers across multiple domains. It includes full texts of cited works and is designed so every source paper is available in full, enabling controlled evaluation of full‑text related‑work generation. The paper benchmarks various models, shows that large language models struggle with massive full‑text contexts, and introduces a statement‑level evaluation framework to better assess long‑form structured outputs.

By Martin Docekal, Martin Fajcik, Pavel Smrz