TRACE: Triplet Recovery via Arrowhead-Centric Extraction for Flowchart Understanding

Daozhu Dong, Kaiwen Shi, Dan Si, Xiaoyu Hao, Tong Liu, Wenjie Zhang, Gong Cheng


Abstract
Flowcharts are widely used in business management and software development to represent process logic and user interactions. Understanding the semantics they encode is essential for downstream applications such as visual question answering. Existing methods either detect components and reconstruct topology, which suffers from cascaded errors and rigid shape assumptions, or feed the whole image to a vision language model (VLM), which dilutes attention on dense diagrams and often reverses edge directions. Inspired by cognitive science findings that humans read flowcharts by tracing arrows, we propose TRACE (Triplet Recovery via Arrowhead-Centric Extraction), a three-stage framework. An offline stage synthesizes aligned training data from text-format flowchart sources (e.g., Mermaid, BPMN XML) and fine-tunes the two models used online: a detector that locates every arrowhead, and then a VLM that extracts one triplet per arrowhead. Each output triplet is grounded to a detected arrowhead, enabling traceable diagnosis. Experiments show that TRACE substantially improves flowchart understanding accuracy and improves downstream QA accuracy.
Anthology ID:
2026.emnlp-main.1704
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
38812–38833
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1704/
DOI:
Bibkey:
Cite (ACL):
Daozhu Dong, Kaiwen Shi, Dan Si, Xiaoyu Hao, Tong Liu, Wenjie Zhang, and Gong Cheng. 2026. TRACE: Triplet Recovery via Arrowhead-Centric Extraction for Flowchart Understanding. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 38812–38833, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
TRACE: Triplet Recovery via Arrowhead-Centric Extraction for Flowchart Understanding (Dong et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.1704.pdf