arXiv Machine Learning By Shiliang Luo (East China Normal University)

PA-CDM: Position-Aware Character Detection Matching for Evaluating Handwritten Mathematical Expression Recognition

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The paper introduces PA-CDM, a new position‑aware character detection matching metric for handwritten mathematical expression recognition that improves on existing render‑based and tree‑edit metrics by incorporating position‑forest encoding and divergence‑level weighting. It also presents StructPerturb v2.0, a benchmark of 1,340 controlled perturbation pairs, and a cross‑metric consistency protocol that includes a sensitivity matrix, a human study, and LLM‑judge calibration. In a six‑annotator study, PA‑CDM achieves the highest correlation with human judgments (Spearman rho = 0.9535) among seven automatic metrics, approaching the performance of a costly LLM judge while remaining deterministic and cost‑free.

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