ChulaNLP at SemEval-2026 Task 5: Regression-Calibrated LLM for Word-Sense Scoring

Wayu Limsuwan, Attapol Rutherford


Abstract
Word Sense Disambiguation (WSD) is typically framed as a classification task that selects one correct sense for a word. However, real language is often less clear-cut, as a homonym may support several plausible interpretations. SemEval 2026 Task 5 addresses this limitation by introducing plausibility rating, where models estimate how likely each sense is in a narrative context, aligning predictions with graded human judgments. We use GlossBERT and BEM as encoder-based baselines and show that large language models (LLMs) produce more accurate plausibility estimates. Building on this observation, we propose a regression-calibrated LLM model that applies linear regression to adjust raw LLM outputs to better match human annotation patterns. Our calibrated model achieves the highest within-standard-deviation accuracy among our evaluated systems, demonstrating that lightweight post-hoc calibration can substantially improve LLM performance on graded semantic judgment tasks.
Anthology ID:
2026.semeval-1.343
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:
2723–2728
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.343/
DOI:
Bibkey:
Cite (ACL):
Wayu Limsuwan and Attapol Rutherford. 2026. ChulaNLP at SemEval-2026 Task 5: Regression-Calibrated LLM for Word-Sense Scoring. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 2723–2728, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
ChulaNLP at SemEval-2026 Task 5: Regression-Calibrated LLM for Word-Sense Scoring (Limsuwan & Rutherford, SemEval 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.343.pdf
Supplementarymaterial:
 2026.semeval-1.343.SupplementaryMaterial.zip