arXiv Machine Learning

Stop Removing Stopwords: How an Inherited Preprocessing Default Distorts Legal Text-as-Data

The paper critiques the common practice of stopword removal in legal text analysis, showing that standard stoplists actually degrade performance on binary classification tasks involving Supreme Court opinions. By exhaustively testing the removal of each of ~18,500 candidate words, the authors find that no stoplist—generic or optimized—outperforms a no‑removal baseline, and that models cannot predict which words are beneficial to remove. The study argues that inherited preprocessing defaults can distort the doctrinal and ideological signals that legal scholars aim to recover, calling into question the validity of such practices.

arXiv AI
Jul 7

Shortcut Learning in Legal Judgment Prediction: Empirical Evidence from the UK Employment Tribunal

arXiv:2607. 04261v1 Announce Type: new Abstract: Current Legal Judgment Prediction (LJP) is constrained by its reliance on post-hoc judicial materials, increasing the likelihood that models perform retrospective classification rather than true forecasting.

By Joe Watson, Joana Ribeiro de Faria, Marcus Tomalin, M{\aa}ns Magnusson, Huiyuan Xie, Hao Tian Yeung, Felix Steffek
arXiv AI
2d ago

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
2d ago

Legal text classification in Korean sexual offense cases: from traditional machine learning to large language models with XAI insights

The paper evaluates legal text classification models for Korean sexual offense cases, comparing traditional machine learning, large language models, and fine‑tuned domain models. Fine‑tuned KLUE‑BERT achieved the highest accuracy of 99.3%, outperforming GPT‑3.5, GPT‑4.0, and other traditional approaches. Explainable AI techniques were used to analyze predictions, revealing linguistic features that influence decisions and highlighting limitations in capturing subtle textual cues, especially in real‑world KICS data.

By Jeongmin Lee
arXiv AI
Aug 11

PROSLEX: A Novel Dataset for Expert-Annotated Legal Statute Prediction for Indian Judiciary

arXiv:2608. 08830v1 Announce Type: new Abstract: Legal Statute Prediction (LSP) involves automatically identifying relevant legal statutes given factual descriptions in legal documents, typically framed as a multi-label classification task within natural language processing and information retrieval research.

By Subinay Adhikary, Upal Bhattacharya, Vivek Kumar Singh, Anurag Sharma, Shubham Kumar Nigam, Suvasis Das, Shouvik Kumar Guha, Koustav Rudra, Kripabandhu Ghosh
arXiv Computation and Language
Sep 24

Classifying Interpretive Canons at the Sentence Level: A Benchmark from the German Federal Constitutional Court

The paper introduces a sentence‑level benchmark for judging large language models’ ability to classify interpretive canons used by the German Federal Constitutional Court, based on Larenz’s framework. It operationalizes these canons as classification criteria, provides a dataset of court decisions annotated at the sentence level, and evaluates four LLMs with both expert hand‑written prompts and prompts optimized via Genetic‑Pareto. The results show mean F1 scores between 70.4 and 79.2, with grammatical interpretation being the easiest and systematic interpretation the hardest, and indicate that expert prompts already offer a strong baseline.

By Felix Ringe
arXiv Computation and Language
Aug 28

Legal Rule Induction: Towards Generalizable Principle Discovery from Analogous Judicial Precedents

The paper introduces Legal Rule Induction (LRI), a task that seeks to extract concise, generalizable doctrinal rules from analogous judicial precedents. It presents a reproducible pipeline for constructing LRI datasets and, using Chinese law, releases the first benchmark comprising 5,121 case sets (38,088 court cases) for training and 216 expert‑annotated gold test sets. Experiments show that state‑of‑the‑art large language models struggle with over‑generalization and hallucination, but training on the new dataset significantly improves their ability to capture nuanced rule patterns across similar cases.

By Wei Fan, Tianshi Zheng, Yiran Hu, Zheye Deng, Weiqi Wang, Baixuan Xu, Chunyang Li, Haoran Li, Weixing Shen, Yangqiu Song