A Diversity Diet for a Healthier Model: A Case Study of French ModernBERT Researchers at French institutions found that diversity-driven sampling can reduce pre-training dataset size by up to 94% and training time by 73% while maintaining performance in ModernBERT models. In some tasks, diversity sampling improved model quality by up to 10 points over random sampling. A Diversity Diet for a Healthier Model: A Case Study of French ModernBERT https://aclanthology.org/2026.findings-acl.1707.pdf Louis Estève /people/louis-esteve/ , Christophe Servan /people/christophe-servan-7075/ , Thomas Lavergne /people/thomas-lavergne/unverified/ , Agata Savary /people/agata-savary/ Abstract Diversity has been gaining interest in the NLP community in recent years. At the same time, state-of-the-art transformer models such as ModernBERT use very large pre-training datasets, which are driven by size rather than by diversity. This summons to investigate theimpact of diversity on pre-training. We do so in this study, with the express intent of reducing pre-training dataset size, while retaining atleast comparable performance. We compare diversity-driven sampling algorithms, and we use the best one to pre-train several ModernBERT models on French with a fixed compute budget. We fine-tune and evaluate them on a variety of French benchmarks. We compare them with models pre-trained on randomly sampled data of commensurate size, with the same compute budget. We find that both random and diversity-driven sampling may reduce the pre-training dataset by up to 94% and the pre-training time by up to 73% while maintaining performance. Moreover, in some tasks, the inherent quality of models, estimated via head-only fine-tuning, is up to 10 points higher with diversity sampling than with random sampling.- Anthology ID: - 2026.findings-acl.1707 - Volume: Findings of the Association for Computational Linguistics: ACL 2026 /volumes/2026.findings-acl/ - Month: - July - Year: - 2026 - Address: - San Diego, California, United States - Editors: Maria Liakata /people/maria-liakata/ , Viviane P. Moreira /people/viviane-p-moreira/unverified/ , Jiajun Zhang /people/jiajun-zhang/unverified/ , David Jurgens /people/david-jurgens/ - Venue: Findings /venues/findings/ - SIG: - Publisher: - Association for Computational Linguistics - Note: - Pages: - 34168–34181 - Language: - URL: https://aclanthology.org/2026.findings-acl.1707/ https://aclanthology.org/2026.findings-acl.1707/ - DOI: - Cite ACL : - Louis Estève, Christophe Servan, Thomas Lavergne, and Agata Savary. 2026. A Diversity Diet for a Healthier Model: A Case Study of French ModernBERT https://aclanthology.org/2026.findings-acl.1707/ . In Findings of the Association for Computational Linguistics: ACL 2026 , pages 34168–34181, San Diego, California, United States. Association for Computational Linguistics. - Cite Informal : A Diversity Diet for a Healthier Model: A Case Study of French ModernBERT https://aclanthology.org/2026.findings-acl.1707/ Estève et al., Findings 2026 - PDF: https://aclanthology.org/2026.findings-acl.1707.pdf https://aclanthology.org/2026.findings-acl.1707.pdf