QUBRIC: Co-Designing Queries and Rubrics for RL Beyond Verifiable Rewards

Rongzhi Zhang, Rui Feng, Zhihan Zhang, Jingfeng Yang, Qingyu Yin, Xin Liu, Zixuan Zhang, Priyanka Nigam, Bing Yin, Tuo Zhao, Chao Zhang


Abstract
Rubric-based RL is a promising route for extending reinforcement learning beyond verifiable rewards, yet existing methods optimize rubrics while treating the query distribution as fixed. We identify a structural bottleneck: rubric quality is constrained by query structure. Open-ended queries yield vague rubrics; naively narrowing them introduces fabricated references that no model can verify, so all responses fail and training receives no reward signal. We present QUBRIC, a framework that co-designs queries and rubrics. Teacher-derived key points ground the rewriting of open-ended prompts into scenario-based, evaluable questions. Contrastive rubric generation then turns teacher–policy gaps into query-level criteria, and learnability filtering retains only informative query–rubric pairs for GRPO training. QUBRIC achieves a +5.5 point gain on ArenaHard over the SFT baseline. Trained only on instruction-following data, it further transfers to three held-out benchmarks spanning legal, moral, and narrative reasoning (+6.3 points on average), with improvements concentrated in reasoning-related dimensions. These results provide evidence that co-designing queries and rubrics can make rubric-based RL a practical complement to RLVR beyond strictly verifiable tasks.
Anthology ID:
2026.emnlp-main.728
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
16914–16931
Language:
URL:
https://aclanthology.org/2026.emnlp-main.728/
DOI:
Bibkey:
Cite (ACL):
Rongzhi Zhang, Rui Feng, Zhihan Zhang, Jingfeng Yang, Qingyu Yin, Xin Liu, Zixuan Zhang, Priyanka Nigam, Bing Yin, Tuo Zhao, and Chao Zhang. 2026. QUBRIC: Co-Designing Queries and Rubrics for RL Beyond Verifiable Rewards. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 16914–16931, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
QUBRIC: Co-Designing Queries and Rubrics for RL Beyond Verifiable Rewards (Zhang et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.728.pdf