Generate, Verify, and Refine: Event Timelines for Robust Video-Grounded Dialogue Systems

Wiradee Imrattanatrai, Masaki Asada, Kimihiro Hasegawa, Susan Holm, Ken Fukuda, Teruko Mitamura


Abstract
Video-grounded dialogue (VGD) requires models to generate coherent responses by tracking and reasoning over temporally evolving events in video content. However, existing approaches offer limited ability to capture temporal dependencies, particularly in complex scenarios. In this paper, we present a framework that integrates structured event timelines with verification-aware reasoning to improve temporal consistency in VGD. We represent video content as structured states and temporally ordered actions, enabling models to both infer event timelines from video segments and leverage them to guide response generation. In addition, to address the inherent noise in predicted structure timelines, we introduce a Generate-Verify-Refine (GVR) mechanism that explicitly evaluates and revises unreliable event predictions, thereby reducing the propagation of upstream errors. Experiments on the VDAct benchmark show that our approach consistently improves dialogue quality across models, achieving gains of up to +13.0 LAVE and accuracy over unstructured grounding. Human evaluation further demonstrates improvements of 20.7-31.9 points in response correctness. Additional analysis shows that while better event predictions correlate with stronger dialogue performance, naive reliance on structured outputs can degrade results, highlighting the need for verification-aware reasoning. Our implementation of GVR on event timelines for VGD is available at https://github.com/aistairc/GVR-VGD.
Anthology ID:
2026.aacl-short.5
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 2: Short Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
49–68
Language:
URL:
https://aclanthology.org/2026.aacl-short.5/
DOI:
Bibkey:
Cite (ACL):
Wiradee Imrattanatrai, Masaki Asada, Kimihiro Hasegawa, Susan Holm, Ken Fukuda, and Teruko Mitamura. 2026. Generate, Verify, and Refine: Event Timelines for Robust Video-Grounded Dialogue Systems. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 2: Short Papers), pages 49–68, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
Generate, Verify, and Refine: Event Timelines for Robust Video-Grounded Dialogue Systems (Imrattanatrai et al., AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-short.5.pdf