CASTLE: A Comprehensive Benchmark for Evaluating Student-Tailored Personalized Safety in Large Language Models

Rui Jia, Ruiyi Lan, Fengrui Liu, Zhongxiang Dai, Bo Jiang, Jing Shao, Jingyuan Chen, Guandong Xu, Fei Wu, Min Zhang


Abstract
Large language models (LLMs) have advanced the development of personalized learning in education. However, their inherent generation mechanisms often produce homogeneous responses to identical prompts. This “one-size-fits-all” mechanism overlooks the substantial heterogeneity in students’ cognitive and psychological characteristics, thereby posing potential safety risks to vulnerable groups. Existing safety evaluations primarily rely on context-independent metrics such as factual accuracy, bias, or toxicity, which fail to capture the divergent harms that the same response might cause across different student attributes. To address this gap, we propose the concept of “Student-Tailored Personalized Safety” and construct CASTLE based on educational theories. This benchmark covers 15 educational safety risks and 14 student attributes, comprising 92,908 bilingual scenarios. We further design three evaluation metrics: Risk Sensitivity, measuring the model’s ability to detect risks; Emotional Empathy, evaluating the model’s capacity to recognize student states; and Student Alignment, assessing the match between model responses and student attributes. Experiments on 18 LLMs demonstrate that CASTLE poses a significant challenge: all models scored below an average safety score of 2.5 out of 5, indicating substantial deficiencies in personalized safety assurance. The code is available at https://github.com/ECNU-RAIL/CASTLE-EMNLP2026.
Anthology ID:
2026.emnlp-main.1008
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
23188–23222
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URL:
https://aclanthology.org/2026.emnlp-main.1008/
DOI:
Bibkey:
Cite (ACL):
Rui Jia, Ruiyi Lan, Fengrui Liu, Zhongxiang Dai, Bo Jiang, Jing Shao, Jingyuan Chen, Guandong Xu, Fei Wu, and Min Zhang. 2026. CASTLE: A Comprehensive Benchmark for Evaluating Student-Tailored Personalized Safety in Large Language Models. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 23188–23222, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
CASTLE: A Comprehensive Benchmark for Evaluating Student-Tailored Personalized Safety in Large Language Models (Jia et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1008.pdf