Takoyaki at SemEval-2026 Task 3: Ensembling LLM Predictions using Demonstration Retrieval for Dimensional Aspect-based Sentiment Analysis

Kosuke Yamada, Sho Takase, Ryosuke Kohita


Abstract
This paper describes our system for SemEval-2026 Task 3 (DimABSA). We participate in Subtask 2 (DimASTE), which requires extracting triplets of aspect term, opinion term, and valence-arousal scores from review sentences, and Subtask 3 (DimASQP), which additionally requires aspect category classification to form quadruplets. Our proposed system consists of a multi-step pipeline: (1) retrieval-based in-context learning using BM25 to select relevant demonstrations for LLM inference, (2) agreement-based ensemble combining LLM predictions from multiple retrieval variants, and, for a subset of datasets, (3) error-pattern correction refining uncertain predictions using correction rule sets based on training data. Retrieval-based ICL and the agreement-based ensemble show consistent improvements across languages and domains. Error-pattern correction yields further improvement for the Japanese dataset. To further investigate output quality beyond automated evaluation metrics, we conducted human evaluation. The results suggest that LLM-based labeling achieves higher agreement with gold labels than human annotators, and additionally indicate a discrepancy between automated scores and practical output quality.
Anthology ID:
2026.semeval-1.219
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:
1707–1723
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.219/
DOI:
Bibkey:
Cite (ACL):
Kosuke Yamada, Sho Takase, and Ryosuke Kohita. 2026. Takoyaki at SemEval-2026 Task 3: Ensembling LLM Predictions using Demonstration Retrieval for Dimensional Aspect-based Sentiment Analysis. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 1707–1723, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
Takoyaki at SemEval-2026 Task 3: Ensembling LLM Predictions using Demonstration Retrieval for Dimensional Aspect-based Sentiment Analysis (Yamada et al., SemEval 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.219.pdf