CommunityBench: Benchmarking Community-Level Alignment across Diverse Groups and Tasks

Jiayu Lin, Zhongyu Wei


Abstract
Large language models (LLMs) alignment ensures model behaviors reflect human value. Existing alignment strategies primarily follow two paths: one assumes a universal value set for a unified goal (i.e., one-size-fits-all), while the other treats every individual as unique to customize models (i.e., individual-level). However, assuming a monolithic value space marginalizes minority norms, while tailoring individual models is prohibitively expensive. Recognizing that human society is organized into social clusters with high intra-group value alignment, we propose community-level alignment as a "middle ground". Practically, we introduce CommunityBench, the first large-scale benchmark for community-level alignment evaluation, featuring four tasks grounded in Common Identity and Common Bond theory. With CommunityBench, we conduct a comprehensive evaluation of various foundation models on CommunityBench, revealing that current LLMs exhibit limited capacity to model community-specific preferences. Furthermore, we investigate the potential of community-level alignment in facilitating individual modeling, providing a promising direction for scalable and pluralistic alignment.
Anthology ID:
2026.emnlp-main.1498
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:
34226–34247
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1498/
DOI:
Bibkey:
Cite (ACL):
Jiayu Lin and Zhongyu Wei. 2026. CommunityBench: Benchmarking Community-Level Alignment across Diverse Groups and Tasks. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 34226–34247, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
CommunityBench: Benchmarking Community-Level Alignment across Diverse Groups and Tasks (Lin & Wei, EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1498.pdf