ChainReaction: Causal Chain-Guided Reasoning for Modular and Explainable Causal-Why Video Question Answering [CVPR 2026]
Paritosh Parmar1,2, Eric Peh1,2, Basura Fernando1,2,3,
1 Institute of High Performance Computing, Agency for Science, Technology and Research, Singapore, 2Centre for Frontier AI Research, Agency for Science, Technology and Research, Singapore, 3College of Computing and Data Science, Nanyang Technological University, Singapore
- Pre-process and training code
- Code release to generate own Causal Chains
- Causal Chains Release
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24 Dec 2025We release our paper on arxiv.
Existing Causal-Why Video Question Answering (VideoQA) models often struggle with higher-order reasoning, relying on opaque, monolithic pipelines that entangle video understanding, causal inference, and answer generation. These black-box approaches offer limited interpretability and tend to depend on shallow heuristics. We propose a novel, modular paradigm that explicitly decouples causal reasoning from answer generation, introducing natural language causal chains as interpretable intermediate representations. Inspired by human cognitive models, these structured cause-effect sequences bridge low-level video content with high-level causal reasoning, enabling transparent and logically coherent inference. Our two-stage architecture comprises a Causal Chain Extractor (CCE) that generates causal chains from video-question pairs, and a Causal Chain-Driven Answerer (CCDA) that derives answers grounded in these chains. To address the lack of annotated reasoning traces, we introduce a scalable method for generating accurate causal chains from existing datasets. We construct human verified causal chains for 46K samples. We also propose CauCo, a new evaluation metric for causality-oriented captioning. Experiments on three large-scale benchmarks demonstrate that our approach not only outperforms state-of-the-art models, but also yields substantial gains in explainability, user trust, and generalization -- positioning the CCE as a reusable causal reasoning engine across diverse domains.
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@inproceedings{parmar2026causal,
title={Causal Chain-Guided Reasoning for Modular and Explainable Causal-Why Video Question Answering},
author={Parmar, Paritosh and Peh, Eric and Fernando, Basura},
booktitle={Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition},
pages={5860--5870},
year={2026}
}
