Generating high-quality charts with Large Language Models (LLMs) presents significant challenges due to limited data and the high cost of scaling through human curation. ⟨instruction,data,code⟩ triplets are scarce and expensive to manually curate as their creation demands technical expertise. To address this scalability challenge, we introduce a reference-free automatic feedback generator, which eliminates the need for costly human intervention. Our novel framework, C2, consists of (1) an automatic feedback provider (ChartAF) and (2) a diverse, reference-free dataset (ChartUIE-8K). The results are compelling: in our first experiment, 74% of respondents strongly preferred, and 10% preferred, the results after feedback. The second post-feedback experiment demonstrates that ChartAF outperform nine baselines. Moreover, ChartUIE-8K significantly improves data diversity by increasing queries, datasets, and chart types by 5982%, 1936%, and 91%, respectively, over benchmarks. Finally, a study of LLM users revealed that 94% of participants preferred ChartUIE-8K's queries, with 93% deeming them aligned with real-world use cases. Core contributions are available as open-source at chartsquared.github.io, with ample qualitative examples.
@article{arxiv.2410.18652,
title = {$C^2$: Scalable Auto-Feedback for LLM-based Chart Generation},
author = {Woosung Koh and Jang Han Yoon and MinHyung Lee and Youngjin Song and Jaegwan Cho and Jaehyun Kang and Taehyeon Kim and Se-Young Yun and Youngjae Yu and Bongshin Lee},
journal= {arXiv preprint arXiv:2410.18652},
year = {2025}
}