BOE-XSUM: Extreme Summarization in Clear Language of Spanish Legal Decrees and Notifications
Andrés Fernández García, Javier de la Rosa, Julio Gonzalo, Roser Morante, Enrique Amigó, Alejandro Benito-Santos, Jorge Carrillo-de-Albornoz, Víctor Fresno, Adrian Ghajari, Guillermo Marco, Laura Plaza, Eva Sánchez Salido
Published: 2025/9/29
Abstract
The ability to summarize long documents succinctly is increasingly important in daily life due to information overload, yet there is a notable lack of such summaries for Spanish documents in general, and in the legal domain in particular. In this work, we present BOE-XSUM, a curated dataset comprising 3,648 concise, plain-language summaries of documents sourced from Spain's ``Bolet\'{\i}n Oficial del Estado'' (BOE), the State Official Gazette. Each entry in the dataset includes a short summary, the original text, and its document type label. We evaluate the performance of medium-sized large language models (LLMs) fine-tuned on BOE-XSUM, comparing them to general-purpose generative models in a zero-shot setting. Results show that fine-tuned models significantly outperform their non-specialized counterparts. Notably, the best-performing model -- BERTIN GPT-J 6B (32-bit precision) -- achieves a 24\% performance gain over the top zero-shot model, DeepSeek-R1 (accuracies of 41.6\% vs.\ 33.5\%).