North or South? Diagnosing LLMs’ Understanding of North Korean Language, Society, and Knowledge

Kiwoong Park, Seyoung Song, Donghyun Woo, Alice Oh


Abstract
Large Language Models (LLMs) have made substantial progress in multilingual question answering, yet their ability to understand low-resource sociolinguistic contexts remains underexplored. We study North Korea as a unique testbed where decades of division have produced distinct differences from South Korea in vocabulary, orthography, norms, and ideological discourse. We introduce LENS (Language and sociocultural Evaluation for North Korean Society), a human-validated benchmark of 1,765 questions evaluating LLMs across three dimensions: linguistic robustness, sociocultural perspective alignment, and domain-specific knowledge. Evaluating diverse recent LLMs, we find a modest performance drop on North Korean language inputs, a larger gap in sociocultural perspective alignment, and severe limitations on domain-specific knowledge. Qualitative analysis reveals that models often conflate formal institutions with lived realities, project liberal-democratic assumptions, or rely on coarse stereotypes. Our results demonstrate that linguistic similarity alone does not guarantee sociocultural or domain-specific understanding, highlighting the critical need for grounded evaluation resources for underrepresented cultural and political contexts.
Anthology ID:
2026.aacl-long.21
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
408–426
Language:
URL:
https://aclanthology.org/2026.aacl-long.21/
DOI:
Bibkey:
Cite (ACL):
Kiwoong Park, Seyoung Song, Donghyun Woo, and Alice Oh. 2026. North or South? Diagnosing LLMs’ Understanding of North Korean Language, Society, and Knowledge. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 408–426, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
North or South? Diagnosing LLMs’ Understanding of North Korean Language, Society, and Knowledge (Park et al., AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-long.21.pdf