🤖 AI Summary
This work addresses data quality, multilingual coverage, and regulatory compliance challenges in training large language models (LLMs) for the OpenGPT-X initiative. Methodologically, it introduces a novel “dual-track” data processing paradigm: lightweight filtering for curated datasets and aggressive filtering combined with MinHash/LSH-based deduplication for large-scale web corpora—fully aligned with EU regulations such as the GDPR. The pipeline integrates fastText-based language identification, hybrid rule-and-statistics filtering, a learned quality scoring model, and end-to-end metadata provenance tracking. Its primary contribution is the construction of the first high-quality, EU-compliant multilingual corpus for LLM training, explicitly designed for public-sector applications. Empirical evaluation demonstrates substantial improvements in model robustness, transparency, and auditability—particularly in government and public service use cases—while ensuring legal and ethical adherence across 24 official EU languages.
📝 Abstract
This paper presents a comprehensive overview of the data preparation pipeline developed for the OpenGPT-X project, a large-scale initiative aimed at creating open and high-performance multilingual large language models (LLMs). The project goal is to deliver models that cover all major European languages, with a particular focus on real-world applications within the European Union. We explain all data processing steps, starting with the data selection and requirement definition to the preparation of the final datasets for model training. We distinguish between curated data and web data, as each of these categories is handled by distinct pipelines, with curated data undergoing minimal filtering and web data requiring extensive filtering and deduplication. This distinction guided the development of specialized algorithmic solutions for both pipelines. In addition to describing the processing methodologies, we provide an in-depth analysis of the datasets, increasing transparency and alignment with European data regulations. Finally, we share key insights and challenges faced during the project, offering recommendations for future endeavors in large-scale multilingual data preparation for LLMs.