Reasoning Beyond Labels: Measuring LLM Sentiment in Low-Resource, Culturally Nuanced Contexts

Millicent Ochieng, Anja Thieme, Ignatius Ezeani, Risa Ueno, Samuel Chege Maina, Keshet Ronen, Javier Gonzalez, Jacki O'Neill


Abstract
Sentiment analysis in low-resource, culturally nuanced contexts challenges conventional NLP approaches that assume fixed labels and universal affective expressions. We present a diagnostic framework that treats sentiment as a context-dependent, culturally embedded construct, and evaluate how large language models (LLMs) reason about sentiment in informal, code-mixed WhatsApp messages from Nairobi youth health groups. Using human-annotated data, sentiment-flipped counterfactuals, and rubric-based explanation evaluation, we probe LLM interpretability, robustness, and alignment with human reasoning. Framing our evaluation through a social science measurement lens, we operationalize LLM outputs as an instrument for measuring the abstract concept of sentiment. Our findings reveal significant variation in model reasoning quality, with top-tier LLMs demonstrating greater interpretive stability, while smaller open-weight models in our study show reduced stability under ambiguity or sentiment shifts. This work highlights the need for culturally sensitive, reasoning-aware AI evaluation in complex, real-world communication.
Anthology ID:
2026.africanlp-main.7
Volume:
Proceedings of the 7th Workshop on African Natural Language Processing (AfricaNLP 2026)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Everlyn Asiko Chimoto, Constantine Lignos, Shamsuddeen Muhammad, Idris Abdulmumin, Clemencia Siro, David Ifeoluwa Adelani
Venues:
AfricaNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
64–81
Language:
URL:
https://aclanthology.org/2026.africanlp-main.7/
DOI:
Bibkey:
Cite (ACL):
Millicent Ochieng, Anja Thieme, Ignatius Ezeani, Risa Ueno, Samuel Chege Maina, Keshet Ronen, Javier Gonzalez, and Jacki O'Neill. 2026. Reasoning Beyond Labels: Measuring LLM Sentiment in Low-Resource, Culturally Nuanced Contexts. In Proceedings of the 7th Workshop on African Natural Language Processing (AfricaNLP 2026), pages 64–81, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Reasoning Beyond Labels: Measuring LLM Sentiment in Low-Resource, Culturally Nuanced Contexts (Ochieng et al., AfricaNLP 2026)
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PDF:
https://aclanthology.org/2026.africanlp-main.7.pdf