arXiv Computation and Language

Thunder-DeID+: Boundary-Aware Korean De-identification from Court Judgments to Broader Sensitive Documents

Thunder‑DeID+ is a Korean de‑identification system that improves boundary precision, label granularity, and recall when applied to court judgments and other sensitive documents. It introduces a refined three‑tier PII taxonomy and a boundary‑aware tokenizer that augments a pretrained BPE vocabulary with N‑gram and boundary‑scoring components, enabling better alignment of token and PII span boundaries. Evaluations show the tokenizer raises the W. Strict Typed F1‑score from 0.76‑0.77 to 0.87‑0.88 across models, and fine‑tuning on 1,000 broader documents yields a 0.93 score, demonstrating effective transfer beyond court judgments.

arXiv AI
Oct 2

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 Machine Learning
Sep 18

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.

By Gregory M. Dickinson
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
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