titleChartographer: Counterfactual Chart Generation for Evaluating Vision-Language Models
authorsYifan Jiang, Dae Yon Hwang, Jesse C. Cresswell, Freda Shi
date2026-05-26
venuearXiv (preprint, not peer reviewed)
idarXiv:2605.27311
linksabs pdf hf code
abstractChart question-answering (QA) benchmarks aim to pose questions that require visual reasoning to correctly answer, but models can often reach solutions through shortcuts or prior familiarity with a chart based on their own background knowledge. To strictly evaluate visual reasoning, we propose counterfactual charts where the chart-question task remains fixed, but underlying chart and the corresponding answer are varied. We introduce Chartographer, a framework to reverse engineer charts into executable code, validate reconstruction fidelity, generate seed-controlled counterfactual variants, and derive new answers from executable QA logic. We apply this framework to existing chart QA datasets and evaluate proprietary and open-source vision-language models (VLMs), measuring variation sensitivity and generalizability. Counterfactual charts reveal failures hidden by single-chart performance: VLMs often fail to generalize after answering the original chart correctly. We find failures are most prevalent when updated charts require novel visual reasoning pathways.

cite

@misc{jiang2026chartographer,
  title={Chartographer: Counterfactual Chart Generation for Evaluating Vision-Language Models},
  author={Yifan Jiang and Dae Yon Hwang and Jesse C. Cresswell and Freda Shi},
  year={2026},
  eprint={2605.27311},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2605.27311}
}