Embodied Multi-Agent Coordination by Aligning World Models Through Dialogue

Vardhan Dongre, Dilek Hakkani-Tur


Abstract
Effective collaboration between embodied agents requires more than acting in a shared environment, it demands communication grounded in each agent’s evolving understanding of the world. When agents can only partially observe their surroundings, coordination without communication is provably hard, but communication can, in principle, bridge this gap by allowing agents to share observations and align their world models. In this work, we examine whether LLM-based embodied agents actually realize the ability to communicate. We extend PARTNR, a benchmark for collaborative household robotics, with a natural-language dialogue channel that enables two agents with partial observability to communicate during task execution. To evaluate whether dialogue leads to genuine world-model alignment rather than superficial coordination, we propose a framework for measuring world-model alignment defined over per-agent world graphs: observation convergence (do private world models align over time?), information novelty (do messages convey what the partner lacks?), and belief-sensitive messaging (do agents model what their partner knows?). Our experiments across three LLMs reveal that dialogue reduces action conflicts 40–83 percentage points but degrades task success relative to silent coordination. Using our metrics, we characterize the gap between superficial coordination and genuine world-model alignment, and identify where current models fall on this spectrum.
Anthology ID:
2026.sigdial-1.21
Volume:
Proceedings of the 27th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Month:
August
Year:
2026
Address:
Atlanta, Georgia, USA
Editors:
Jinho D. Choi, Yun-Nung Chen, Kotaro Funakoshi, Ali Emami
Venue:
SIGDIAL
SIG:
SIGDIAL
Publisher:
Association for Computational Linguistics
Note:
Pages:
293–306
Language:
URL:
https://aclanthology.org/2026.sigdial-1.21/
DOI:
Bibkey:
Cite (ACL):
Vardhan Dongre and Dilek Hakkani-Tur. 2026. Embodied Multi-Agent Coordination by Aligning World Models Through Dialogue. In Proceedings of the 27th Annual Meeting of the Special Interest Group on Discourse and Dialogue, pages 293–306, Atlanta, Georgia, USA. Association for Computational Linguistics.
Cite (Informal):
Embodied Multi-Agent Coordination by Aligning World Models Through Dialogue (Dongre & Hakkani-Tur, SIGDIAL 2026)
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PDF:
https://aclanthology.org/2026.sigdial-1.21.pdf