YNU-HPCC at SemEval-2026 Task 12: Retrieval-Guided Reasoning with Teacher Distillation for Abductive Event Reasoning
Summary
The YNU-HPCC system, developed for SemEval-2026 Task 12 on Abductive Event Reasoning (AER), addresses the challenge of identifying direct causes from multi-document retrieved evidence containing distractors. This task is complicated by sparse evidence in long documents and a boundary-sensitive set-level evaluation. The system employs a two-stage framework. Stage 1 utilizes a DeBERTa-v3-base student model with retrieval-guided evidence modeling, where documents are split into overlapping windows, BM25 ranks and filters candidates, and Top-K pooling aggregates scores. Stage 2 enhances generalization by distilling soft targets from a Qwen-14B teacher model, incorporating temperature scaling and high-confidence filtering to mitigate pseudo-label noise. The system achieved an official dev score of 0.9712 (micro-F1 0.9746, macro-F1 0.9745) and improved its test score from 0.46 to 0.73, securing 84th place among 221 submissions.
Key takeaway
For NLP Engineers tackling abductive reasoning or similar tasks with sparse, multi-document evidence, consider implementing a two-stage framework. Your system could benefit from an initial retrieval-guided stage using document windowing and BM25 filtering to manage long contexts, followed by a teacher distillation stage. This approach, leveraging a larger teacher model like Qwen-14B for soft targets and noise reduction, can significantly improve generalization and F1 scores, as demonstrated by the YNU-HPCC system's performance increase from 0.46 to 0.73.
Key insights
Retrieval-guided reasoning combined with teacher distillation effectively improves abductive event reasoning performance on sparse evidence.
Principles
- Address sparse evidence with windowing and retrieval.
- Aggregate evidence scores via Top-K pooling.
- Teacher distillation improves generalization and reduces noise.
Method
A two-stage framework: first, a DeBERTa-v3-base student uses BM25-filtered windows and Top-K pooling; second, a Qwen-14B teacher distills soft targets with temperature scaling and high-confidence filtering.
In practice
- Split long documents into overlapping windows.
- Use BM25 for initial evidence ranking.
- Apply temperature scaling in knowledge distillation.
Topics
- Abductive Event Reasoning
- Retrieval-Guided Reasoning
- Teacher Distillation
- DeBERTa-v3
- Qwen-14B
- SemEval-2026
Best for: Research Scientist, AI Scientist, Machine Learning Engineer, NLP Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Paper Index on ACL Anthology.