Legal Nugget Extraction for Granular Retrieval over Long Jurisprudential Texts
Judicial case documents are typically lengthy, with critical legal arguments constituting only a small fraction of the text, which limits the effectiveness of conventional full-text retrieval. This work proposes a fine-grained retrieval framework that, for the first time, integrates legal nugget extraction with dense retrieval. The approach first automatically extracts self-contained legal nuggets from case documents, constructs an embedding index at the nugget level, and performs dense retrieval over these nuggets; results are then aggregated to produce document-level rankings. Evaluated on the JUA-Juris and JurisTCU datasets, the method achieves NDCG@10 scores of 0.20461 and 0.32696, respectively, significantly outperforming baseline approaches and enabling precise case retrieval tailored to legal argument queries.