When Neutral Turns Negative: Cross-Domain Failure Modes in Hinglish Political Sentiment Analysis

Rahul Chennuru, Kolawole John Adebayo


Abstract
Sentiment analysis models are increasingly deployed to analyze political discourse, yet strong in-domain performance does not guarantee robustness under domain shift. We study cross-domain generalization in Hinglish (Hindi–English code-mixed) sentiment analysis by evaluating a fine-tuned XLM-RoBERTa classifier, trained on 29,000 general-domain Hinglish sentences, on a curated benchmark of politically oriented Hinglish text. While the model achieves 92.02% accuracy in-domain, performance drops to 71.83% under political domain shift. Error analysis reveals a pronounced directional bias with 48.9% of neutral political statements misclassified as negative, indicating a systematic neutrality-to-negative shift. In addition, 87.5% of incorrect predictions are assigned confidence scores above 95%, pointing to severe miscalibration under distribution shift. We further compare these results against an instruction-tuned large language model (Llama 3.3), which achieves 90.85% zero-shot accuracy and 94.37% accuracy with contextual prompting, while substantially reducing neutrality bias. Our findings indicate the need for domain-aware evaluation, calibration diagnostics, and explicit reporting of failure modes when deploying sentiment models in politically sensitive settings.
Anthology ID:
2026.politicalnlp-1.24
Volume:
Proceedings of the 3rd Workshop on Natural Language Processing for Political Sciences (PoliticalNLP 2026)
Month:
May
Year:
2026
Address:
Palma, Mallorca (Spain)
Editors:
Haithem Afli, Houda Bouamor, Wajdi Zaghouani, Sahar Ghannay, Shehenaz Hossain
Venues:
PoliticalNLP | WS
SIG:
Publisher:
ELRA Language Resources Association (ELRA)
Note:
Pages:
219–227
Language:
External URL:
https://lrec.elra.info/lrec2026-ws-politicalnlp-24
DOI:
10.63317/3evceg5aip7m
Bibkey:
Cite (ACL):
Rahul Chennuru and Kolawole John Adebayo. 2026. When Neutral Turns Negative: Cross-Domain Failure Modes in Hinglish Political Sentiment Analysis. In Proceedings of the 3rd Workshop on Natural Language Processing for Political Sciences (PoliticalNLP 2026), pages 219–227, Palma, Mallorca (Spain). ELRA Language Resources Association (ELRA).
Cite (Informal):
When Neutral Turns Negative: Cross-Domain Failure Modes in Hinglish Political Sentiment Analysis (Chennuru & Adebayo, PoliticalNLP 2026)
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