S2J: Bridging the Gap Between Solving and Judging Ability in Generative Reward Models

Shaoning Sun, Jiachen Yu, Zongqi Wang, Xuewei Yang, Tianle Gu, Yujiu Yang


Abstract
With the rapid development of large language models (LLMs), generative reward models (GRMs) have been widely adopted for reward modeling and evaluation. Previous studies have primarily focused on training specialized GRMs by optimizing them on preference datasets with the judgment correctness as supervision. While it’s widely accepted that GRMs with stronger problem-solving capabilities typically exhibit superior judgment abilities, we first identify a significant solve-to-judge gap when examining individual queries. Specifically, the solve-to-judge gap refers to the phenomenon where GRMs struggle to make correct judgments on some queries (14%-37%), despite being fully capable of solving them. In this paper, we propose the Solve-to-Judge (S2J) approach to address this problem. Specifically, S2J simultaneously leverages both the solving and judging capabilities on a single GRM’s output for supervision, explicitly linking the GRM’s problem-solving and evaluation abilities during model optimization, thereby narrowing the gap. Our comprehensive experiments demonstrate that S2J effectively reduces the solve-to-judge gap by 16.2%, thereby enhancing the model’s judgment performance by 5.8%. Notably, S2J achieves state-of-the-art (SOTA) performance among GRMs built on the same base model while utilizing a significantly smaller training dataset.
Anthology ID:
2026.findings-emnlp.1966
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
41919–41940
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1966/
DOI:
Bibkey:
Cite (ACL):
Shaoning Sun, Jiachen Yu, Zongqi Wang, Xuewei Yang, Tianle Gu, and Yujiu Yang. 2026. S2J: Bridging the Gap Between Solving and Judging Ability in Generative Reward Models. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 41919–41940, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
S2J: Bridging the Gap Between Solving and Judging Ability in Generative Reward Models (Sun et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.1966.pdf