Antoine Louis, Gerasimos Spanakis
Statutory article retrieval is the task of automatically retrieving law articles relevant to a legal question. While recent advances in natural language processing have sparked considerable interest in many legal tasks, statutory article retrieval remains primarily untouched due to the scarcity of large-scale and high-quality annotated datasets. To address this bottleneck, we introduce the Belgian Statutory Article Retrieval Dataset (BSARD), which consists of 1,100+ French native legal questions labeled by experienced jurists with relevant articles from a corpus of 22,600+ Belgian law articles. Using BSARD, we benchmark several state-of-the-art retrieval approaches, including lexical and dense architectures, both in zero-shot and supervised setups. We find that fine-tuned dense retrieval models significantly outperform other systems. Our best performing baseline achieves 74.8% R@100, which is promising for the feasibility of the task and indicates there is still room for improvement. By the specificity of the domain and addressed task, BSARD presents a unique challenge problem for future research on legal information retrieval. Our dataset and source code are publicly available.
| Task | Dataset | Metric | Value | Model |
|---|---|---|---|---|
| Information Retrieval | BSARD | Recall@100 | 74.78 | Two-tower Bi-Encoder (RoBERTa) |
| Information Retrieval | BSARD | Recall@200 | 78.04 | Two-tower Bi-Encoder (RoBERTa) |
| Information Retrieval | BSARD | Recall@500 | 83.39 | Two-tower Bi-Encoder (RoBERTa) |
| Information Retrieval | BSARD | Recall@100 | 71.63 | Siamese Bi-Encoder (RoBERTa) |
| Information Retrieval | BSARD | Recall@200 | 78.38 | Siamese Bi-Encoder (RoBERTa) |
| Information Retrieval | BSARD | Recall@500 | 83.77 | Siamese Bi-Encoder (RoBERTa) |
| Information Retrieval | BSARD | Recall@100 | 51.33 | BM25 |
| Information Retrieval | BSARD | Recall@200 | 56.78 | BM25 |
| Information Retrieval | BSARD | Recall@500 | 64.71 | BM25 |