Core Viewpoint - The article discusses the development of the Effective Chart Dataset (ECD), a high-quality synthetic chart dataset aimed at improving the understanding of charts by multimodal large language models (MLLMs) [4][6][25]. Background and Motivation - In fields like scientific research and data analysis, charts are essential for information transmission. MLLMs must accurately identify and understand chart elements and perform deep reasoning on chart data. Current MLLMs struggle with high difficulty scientific chart understanding, achieving only 30%-50% accuracy [4][6]. Dataset Highlights - ECD is introduced as a large-scale, high-quality synthetic chart dataset with a modular data synthesis pipeline and a comprehensive evaluation benchmark called ECDBench [6][10]. - ECD includes over 10,500 charts, covering 25 themes and 29 chart types, with 252 combinations of subplots, making it the most extensive dataset in its category [12][10]. Quality and Diversity - The dataset contains over 300,000 question-answer pairs generated by GPT-4o, ensuring high quality through confidence filtering. Examples include descriptive and reasoning questions related to the charts [10][11]. - ECD achieves the lowest Frechet Inception Distance (FID) score, indicating high visual similarity to real scientific charts, and has a higher average pixel entropy compared to other synthetic datasets, suggesting greater complexity and information content [13][10]. Data Synthesis Process - The five-stage modular data synthesis pipeline includes single chart generation, multi-subplot combinations, visual diversity enhancement, image quality filtering, and question-answer pair generation [15][16]. Model Performance Comparison - ECD significantly improves the performance of various open-source MLLMs when fine-tuned with the dataset. For instance, LLaVA-Next-Llama3-8B showed substantial performance gains across multiple test sets after being trained with ECD [17][23]. Evaluation Benchmark - ECDBench is established as a high-quality evaluation benchmark for assessing the performance of MLLMs before and after fine-tuning with ECD. It provides comprehensive statistics for model evaluation [21][25]. Conclusion - ECD and ECDBench provide a solid foundation for advancing multimodal reasoning, scientific AI assistants, and automated chart generation, enhancing the capabilities of MLLMs in understanding complex chart data [25].