arXiv Machine Learning

LexFlip: A Dissociation Diagnostic for Legal Meaning Preservation Metrics

LexFlip is a diagnostic tool that creates minimal perturbations of Quebec statutory French clauses to test whether legal meaning is preserved when lexical overlap remains high. The dataset contains 373 edits that reverse legal force while keeping 93% of tokens unchanged, and a harness evaluates various metrics, regressors, and judges on these edits. The study finds that most embedding and BERTScore metrics barely differentiate these edits, while bidirectional NLI performs better, and a simple length feature outperforms semantic metrics on the FrJudge human benchmark.

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 AI
Oct 21

An LLM-Based Agent for Legal Compliance Assessment: Architecture, Memory, and Evaluation in a Canadian and Quebec Context

The paper introduces ComplianceAgent, a legal compliance sub‑agent within the COMPASS multi‑agent framework, which uses a large language model to evaluate texts on a fixed rubric across digital sovereignty, carbon impact, compliance, and ethics. The agent grounds its judgments in a reference legal corpus, and if a text scores at or below a critical threshold, it initiates a corrective chain that includes self‑healing rewrites, a compliance label, an explainability report, and escalation to a human reviewer. The authors evaluate the agent in a Canadian and Quebec context on a corpus of thirteen legal instruments and a hand‑annotated gold standard of fifteen texts, demonstrating perfect separation of conforming versus non‑conforming texts, stable scores under repeated queries, and relevant passage retrieval.

By Soukaina Alaoui Ismaili, Jean-Sebastien Dessureault
arXiv Computation and Language
Oct 19

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.

By Gyuseong Lee, Gyeongje Cho, Jongmin Kim, Heejin Kim, Yeonkyoung So, Hyunggeun Jeon, Hyunji M. Park, Sangho Kim, Yoonhee Park, Youngbin Pyo, Jaejin Lee