blue at SemEval-2026 Task 5: NarrBERT : Narrative-Aware BERT for Word Sense Disambiguation
Summary
Team blue's NarrBERT model, a BERT-based cross-encoder regression system, was developed for SemEval-2026 Task 5: AmbiStory, which requires rating the plausibility of word senses in ambiguous sentences. NarrBERT addresses this by encoding the full narrative context, including precontext, the ambiguous sentence, and its ending, alongside candidate sense definitions and examples. Crucially, it enables token-level interaction between narrative cues and sense meanings, a departure from bi-encoder sentence-level methods, to capture subtle disambiguation signals. The model achieved a Spearman rank correlation of 0.66 on the development set. On the official test set, it recorded a Spearman correlation of 0.4866 and an Accuracy-within-Standard-Deviation of 0.6613, significantly surpassing sentence-transformer bi-encoder baselines.
Key takeaway
For NLP Engineers developing advanced word sense disambiguation systems, consider adopting cross-encoder architectures like NarrBERT. Your models should integrate comprehensive narrative context and enable token-level interactions to capture subtle semantic cues, moving beyond simpler bi-encoder approaches. This strategy can yield more human-aligned plausibility ratings, crucial for tasks requiring nuanced contextual understanding.
Key insights
NarrBERT uses a BERT cross-encoder with token-level narrative context to rate word sense plausibility, outperforming bi-encoders.
Principles
- Fine-grain contextual modeling is vital for human-like sense plausibility.
- Token-level interaction improves narrative word sense disambiguation.
- Cross-encoders can outperform bi-encoders for complex contextual tasks.
Method
NarrBERT employs a BERT-based cross-encoder regression model that encodes full narrative context (precontext, ambiguous sentence, ending) with sense definitions and examples, enabling token-level interaction.
In practice
- Integrate full narrative context for improved WSD.
- Prioritize cross-encoder architectures for fine-grained interaction.
- Evaluate WSD models using Spearman correlation and Accuracy-within-Standard-Deviation.
Topics
- Word Sense Disambiguation
- BERT
- Cross-encoder Models
- Narrative Understanding
- SemEval
- Contextual Reasoning
Best for: Research Scientist, AI Scientist, NLP Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Paper Index on ACL Anthology.