Capabilities and Evaluation Biases of Large Language Models in Classical Chinese Poetry Generation: A Case Study on Tang Poetry

Bolei Ma, Yina Yao, Anna-Carolina Haensch


Abstract
Large Language Models (LLMs) are increasingly applied to creative domains, yet their performance in classical Chinese poetry generation and evaluation remains poorly understood. We propose a three-step evaluation framework that combines computational metrics, LLM-as-a-judge assessment, and human expert validation. Using this framework, we evaluate six state-of-the-art LLMs across multiple dimensions of poetic quality, including themes, emotions, imagery, form, and style, in the context of Tang poetry (唐诗) generation. Our analysis reveals a critical "echo chamber" effect: LLMs systematically overrate machine-generated poems that mimic statistical patterns yet fail strict prosodic rules, diverging significantly from human expert judgments. These findings underscore the limitations of using LLMs as standalone evaluators for culturally complex tasks, highlighting the necessity of hybrid human-model validation frameworks.
Anthology ID:
2026.findings-acl.836
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
16933–16957
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.836/
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Cite (ACL):
Bolei Ma, Yina Yao, and Anna-Carolina Haensch. 2026. Capabilities and Evaluation Biases of Large Language Models in Classical Chinese Poetry Generation: A Case Study on Tang Poetry. In Findings of the Association for Computational Linguistics: ACL 2026, pages 16933–16957, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Capabilities and Evaluation Biases of Large Language Models in Classical Chinese Poetry Generation: A Case Study on Tang Poetry (Ma et al., Findings 2026)
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