Single-Agent Generation Surpasses Multi-Agent Systems in Semantic Diversity

Cui Encheng, Shaowen Peng, Kazuhiro Ito, XU Jinsha, Hisada Shohei, Shoko Wakamiya, Eiji Aramaki


Abstract
Multi-Agent Systems (MAS) are commonly used to improve reasoning diversity and robustness by simulating interactions among agents with distinct roles. However, prior work often entangles the contribution of the multi-agent architecture with that of prompt conditioning, making the source of observed diversity gains unclear. We address this confound with a controlled study on divergent thinking tasks, using identical prompt conditioning for MAS and single agent baseline. Under these matched conditions, single agent setups consistently outperform multi-agent systems in semantic diversity. We attribute this gap to information visibility: parallel agents often converge on overlapping ideas, whereas a single agent model can condition on its own generation to avoid redundancy. We further find that a Multi-Output strategy, which prompts a single agent to produce multiple responses within a single inference pass, achieves the highest diversity without degrading logical validity. Together, these results point to a more efficient and effective way to expand diversity, with implications for the design of more efficient agentic frameworks.
Anthology ID:
2026.findings-acl.1894
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:
37993–38008
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1894/
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Cite (ACL):
Cui Encheng, Shaowen Peng, Kazuhiro Ito, XU Jinsha, Hisada Shohei, Shoko Wakamiya, and Eiji Aramaki. 2026. Single-Agent Generation Surpasses Multi-Agent Systems in Semantic Diversity. In Findings of the Association for Computational Linguistics: ACL 2026, pages 37993–38008, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Single-Agent Generation Surpasses Multi-Agent Systems in Semantic Diversity (Encheng et al., Findings 2026)
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