Chi-Bo Lin
2026
B B at SemEval-2026 Task 6: A RoBERTa-based Model with NLI-derived Semantic Features for Clarity-Level Classification of Political Question Evasion
Chi-Bo Lin | Boyang Yu
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Chi-Bo Lin | Boyang Yu
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Equivocation and ambiguity are common in political interviews, where public figures often avoid directly answering challenging questions. We present our submission to SemEval-2026 Task 6, Subtask 1 on English political response clarity classification. Our system builds on RoBERTa and incorporates NLI-derived semantic features to distinguish Clear Reply, Ambivalent, and Clear Non-Reply responses. To address class imbalance and performance instability, we explore class weighting, multi-seed ensembling, and a hierarchical two-stage framework with threshold tuning. Our best model achieves 60% macro-F1 on the official test set and 64% macro-F1 on an additional evaluation set, demonstrating stable performance across splits. Our results show that carefully engineered smaller models, combined with structured semantic features and imbalance-aware training, provide an effective and computationally efficient solution under limited training data.