Diversity and Deliberation in Homogeneous LLM Prediction Polls

Jonas Gebele, Tristan Till, Florian Matthes


Abstract
Multi-agent large language model (LLM) systems increasingly combine model-generated judgments for forecasting and collective decision-making. However, homogeneous agent systems, i.e., those that share a model and evidence, may produce correlated forecasts, and communication may further contract the diversity that remains. We examine these issues in live LLM prediction polls. Across 189 resolved snapshots, mean residual-error correlation was 0.910. Semantic prompt differences were associated with forecast differences, but diversity-aware selection did not detectably outperform prespecified random ensembles. Standard deliberation removed approximately twice as much disagreement benefit as it added through improvements in individual forecasts at the point estimates, with no detectable improvement in aggregate accuracy. In a prospective intervention, a probability-blind summary of forecast-relevant claims retained 93% of initial dispersion, compared with 29% under standard exchange.
Anthology ID:
2026.realm-1.85
Volume:
Proceedings of the Second Workshop for REsearch on Agent Language Models (REALM 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Ehsan Kamalloo, Nicolas Gontier, Nikolai Rozanov, Maryam Hashemzadeh, Akhil Arora
Venues:
REALM | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1229–1235
Language:
URL:
https://aclanthology.org/2026.realm-1.85/
DOI:
Bibkey:
Cite (ACL):
Jonas Gebele, Tristan Till, and Florian Matthes. 2026. Diversity and Deliberation in Homogeneous LLM Prediction Polls. In Proceedings of the Second Workshop for REsearch on Agent Language Models (REALM 2026), pages 1229–1235, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Diversity and Deliberation in Homogeneous LLM Prediction Polls (Gebele et al., REALM 2026)
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PDF:
https://aclanthology.org/2026.realm-1.85.pdf