SemEval-2026 Task 12: Abductive Event Reasoning: Towards Real-World Event Causal Inference for Large Language Models
Pengfei Cao, Mingxuan Yang, Yubo Chen, Chenlong Zhang, Mingxuan Liu, Kang Liu, Jun Zhao
Abstract
Understanding why real-world events occur is important for both natural language processing and practical decision-making, yet direct-cause inference remains underexplored in evidence-rich settings. To address this gap, we organized SemEval-2026 Task 12: Abductive Event Reasoning (AER). The task asks systems to identify the most plausible direct cause of a target event from supporting evidence. We formulate AER as an evidence-grounded multiple choice benchmark that captures key challenges of real-world causal reasoning, including distributed evidence, indirect background factors, and semantically related but non-causal distractors. The shared task attracted 122 participants and received 518 submissions. This paper presents the task formulation, dataset construction pipeline, evaluation setup, and system results. AER provides a focused benchmark for abductive reasoning over real-world events and highlights challenges for future work on causal reasoning and multi-document understanding.- Anthology ID:
- 2026.semeval-1.446
- Volume:
- Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
- Month:
- July
- Year:
- 2026
- Address:
- San Diego, California, USA
- Editors:
- Ekaterina Kochmar, Debanjan Ghosh, Kai North, Mamoru Komachi
- Venues:
- SemEval | WS
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 3659–3672
- Language:
- URL:
- https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.446/
- DOI:
- Cite (ACL):
- Pengfei Cao, Mingxuan Yang, Yubo Chen, Chenlong Zhang, Mingxuan Liu, Kang Liu, and Jun Zhao. 2026. SemEval-2026 Task 12: Abductive Event Reasoning: Towards Real-World Event Causal Inference for Large Language Models. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 3659–3672, San Diego, California, USA. Association for Computational Linguistics.
- Cite (Informal):
- SemEval-2026 Task 12: Abductive Event Reasoning: Towards Real-World Event Causal Inference for Large Language Models (Cao et al., SemEval 2026)
- PDF:
- https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.446.pdf