JudgeMoE: Distributional Aggregation for LLM-as-a-Judge

Yiqi Liu, Joseph James, Yang Wang, Kun Zhao, Chenghao Xiao, Chenghua Lin


Abstract
When an LLM judge scores an output, its score distribution retains uncertainty and disagreement information that is lost after scalar compression. We introduce JudgeMoE, a lightweight aggregator that assigns example-specific weights to cached judge score distributions and fuses them before computing a final score. A protocol study shows that score-range choice is unstable across judge–dataset settings and that soft scoring usually outperforms hard decoding. On the original 10-cell benchmark, JudgeMoE improves mean Spearman over uniform log pooling by +0.079. Applying the same configuration to six additional cells yields a +0.0393 mean gain over the strongest local single judge across 16 cells, with positive differences in 12/16 cells and a one-sided Wilcoxon signed-rank p=0.0091. Validation-based analyses further show that the preferred aggregation method depends on the task and judge pool.
Anthology ID:
2026.aacl-long.49
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1016–1042
Language:
URL:
https://aclanthology.org/2026.aacl-long.49/
DOI:
Bibkey:
Cite (ACL):
Yiqi Liu, Joseph James, Yang Wang, Kun Zhao, Chenghao Xiao, and Chenghua Lin. 2026. JudgeMoE: Distributional Aggregation for LLM-as-a-Judge. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 1016–1042, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
JudgeMoE: Distributional Aggregation for LLM-as-a-Judge (Liu et al., AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-long.49.pdf