Think You Have Solved Commonsense Reasoning? Try HellaSwagUltra

Wenhan Han, Yifan Zhang, Binbin Liu, Mykola Pechenizkiy, Yin Zheng, Meng Fang


Abstract
As LLMs advance, popular commonsense and NLU benchmarks have become saturated, yet multilingual evaluation still lags. Existing benchmarks cover only a small set of languages, and translation based multilingual benchmarks can introduce bias. We introduce HellaSwagUltra, a multilingual commonsense and NLU benchmark with substantial local cultural knowledge. It is built with an automated, continuously extensible pipeline. Instead of explicitly prompting for reasoning, each example implicitly embeds two commonsense or local knowledge facts in the context, and answer options contain subtle cues about whether those facts are violated, requiring models to pick the most plausible continuation. All test items are fully reviewed and corrected by language experts, with ongoing updates. Even the strongest proprietary model (e.g., Gemini-2.5-Pro) reaches only 62.5% accuracy, while GPT-4o and leading open-source models hover around 40%–50%, demonstrating that multilingual commonsense reasoning remains an open challenge.
Anthology ID:
2026.findings-emnlp.1396
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
29739–29758
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1396/
DOI:
Bibkey:
Cite (ACL):
Wenhan Han, Yifan Zhang, Binbin Liu, Mykola Pechenizkiy, Yin Zheng, and Meng Fang. 2026. Think You Have Solved Commonsense Reasoning? Try HellaSwagUltra. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 29739–29758, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Think You Have Solved Commonsense Reasoning? Try HellaSwagUltra (Han et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1396.pdf