CLSep 25, 2025

The role of synthetic data in Multilingual, Multi-cultural AI systems: Lessons from Indic Languages

Microsoft
arXiv:2509.21294v13 citationsh-index: 10Has Code
Originality Incremental advance
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This work addresses the problem of limited data for multilingual and culturally contextualized AI systems, particularly in low-resource Indic languages, by providing a scalable synthetic data generation approach.

The paper tackled the challenge of developing effective multilingual and culturally grounded AI systems for low-resource languages by creating Updesh, a synthetic instruction-following dataset of 9.5M data points across 13 Indian languages, which led to significant gains in generative tasks and narrowed performance gaps for low and medium-resource languages.

Developing AI systems that operate effectively across languages while remaining culturally grounded is a long-standing challenge, particularly in low-resource settings. Synthetic data provides a promising avenue, yet its effectiveness in multilingual and multicultural contexts remains underexplored. We investigate the creation and impact of synthetic, culturally contextualized datasets for Indian languages through a bottom-up generation strategy that prompts large open-source LLMs (>= 235B parameters) to ground data generation in language-specific Wikipedia content. This approach complements the dominant top-down paradigm of translating synthetic datasets from high-resource languages such as English. We introduce Updesh, a high-quality large-scale synthetic instruction-following dataset comprising 9.5M data points across 13 Indian languages, encompassing diverse reasoning and generative tasks with an emphasis on long-context, multi-turn capabilities, and alignment with Indian cultural contexts. A comprehensive evaluation incorporating both automated metrics and human annotation across 10k assessments indicates that generated data is high quality; though, human evaluation highlights areas for further improvement. Additionally, we perform downstream evaluations by fine-tuning models on our dataset and assessing the performance across 15 diverse multilingual datasets. Models trained on Updesh consistently achieve significant gains on generative tasks and remain competitive on multiple-choice style NLU tasks. Notably, relative improvements are most pronounced in low and medium-resource languages, narrowing their gap with high-resource languages. These findings provide empirical evidence that effective multilingual AI requires multi-faceted data curation and generation strategies that incorporate context-aware, culturally grounded methodologies.

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