Large Language Models as Automatic Annotators and Annotation Adjudicators for Fine-Grained Opinion Analysis

Gaurav Negi, M.A. Waskow, John Philip McCrae, Omnia Zayed, Paul Buitelaar


Abstract
Fine-grained opinion analysis enables a detailed understanding of expressed sentiments and their corresponding targets. However, annotating domain-specific datasets requires substantial human effort and financial resources. To address this limitation, we investigate the feasibility of using large language models (LLMs) as automatic annotators for fine-grained opinion analysis. We use a declarative annotation pipeline to reduce prompt engineering when identifying fine-grained opinion spans, and compare rule-based voting against an LLM-based adjudicator for reconciling conflicting predictions. We trial the pipeline across different model sizes on the Aspect Sentiment Triplet Extraction (ASTE) and Aspect-Category-Opinion-Sentiment (ACOS) tasks. Our findings indicate a critical performance bifurcation: LLMs are reliable at the span level yet struggle to faithfully reproduce the relational structures connecting those spans. The better aggregation strategy depends on this complexity: voting suffices for triplets, while quadruples require an adjudicator that re-reads the source. Treating annotator disagreement as an informative signal rather than noise, we further show that agreement between LLM annotators is a calibrated predictor of correctness and can be used to delegate cases with high annotator disagreement to humans.
Anthology ID:
2026.uncertainlp-main.35
Volume:
The Proceedings of the Third Workshop on Uncertainty-Aware NLP
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Wilker Aziz, Jonathan Berant, Bryan Eikema, Evgenia Ilia, Marie-Catherine de Marneffe, Barbara Plank, Artem Shelmanov, Swabha Swayamdipta, Jörg Tiedemann, Artem Vazhentsev, Raúl Vázquez, Chrysoula Zerva
Venues:
UncertaiNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
570–589
Language:
URL:
https://aclanthology.org/2026.uncertainlp-main.35/
DOI:
Bibkey:
Cite (ACL):
Gaurav Negi, M.A. Waskow, John Philip McCrae, Omnia Zayed, and Paul Buitelaar. 2026. Large Language Models as Automatic Annotators and Annotation Adjudicators for Fine-Grained Opinion Analysis. In The Proceedings of the Third Workshop on Uncertainty-Aware NLP, pages 570–589, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Large Language Models as Automatic Annotators and Annotation Adjudicators for Fine-Grained Opinion Analysis (Negi et al., UncertaiNLP 2026)
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PDF:
https://aclanthology.org/2026.uncertainlp-main.35.pdf