Token-Level Pun Location Using Multi-Layer BERT with Mixture of Experts

Rafael Torres Anchiêta, Roney Lira de Sales Santos, Raimundo Santos Moura


Abstract
Humor processing remains a complex challenge in Natural Language Processing, particularly the task of pun location, which involves identifying the specific ”pivot word” that creates linguistic ambiguity. This paper presents a novel two-stage approach for token-level pun location in Portuguese, addressing the scarcity of research in this language. The first stage uses an ensemble of traditional classifiers to filter out non-pun sentences, thereby reducing class imbalance. The second stage employs a pre-trained BERT encoder combined with a Mixture-of-Experts (MoE) layer to capture specialized linguistic features for token classification. We validate our approach on the Puntuguese corpus, achieving an F-score of 0.74 without requiring post-processing heuristics. Interpretability analyses demonstrate that the MoE experts learn to specialize in distinct mechanisms, such as punchline detection and morphological patterns, thereby confirming the model’s capacity to capture the nuances of humor.
Anthology ID:
2026.propor-1.26
Volume:
Proceedings of the 17th International Conference on Computational Processing of Portuguese (PROPOR 2026) - Vol. 1
Month:
April
Year:
2026
Address:
Salvador, Brazil
Editors:
Marlo Souza, Iria de-Dios-Flores, Diana Santos, Larissa Freitas, Jackson Wilke da Cruz Souza, Eugénio Ribeiro
Venue:
PROPOR
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
260–269
Language:
URL:
https://aclanthology.org/2026.propor-1.26/
DOI:
Bibkey:
Cite (ACL):
Rafael Torres Anchiêta, Roney Lira de Sales Santos, and Raimundo Santos Moura. 2026. Token-Level Pun Location Using Multi-Layer BERT with Mixture of Experts. In Proceedings of the 17th International Conference on Computational Processing of Portuguese (PROPOR 2026) - Vol. 1, pages 260–269, Salvador, Brazil. Association for Computational Linguistics.
Cite (Informal):
Token-Level Pun Location Using Multi-Layer BERT with Mixture of Experts (Anchiêta et al., PROPOR 2026)
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PDF:
https://aclanthology.org/2026.propor-1.26.pdf