Rubric-based reinforcement learning extends RL beyond tasks with exact answers or rule-based verifiers by scoring responses against instance-specific criteria. However, this makes reward computation expensive: training requires repeated rubric judging, often with proprietary APIs or local generative LLM judges with 7B parameters or more. We study whether smaller language models can serve as efficient and reliable rubric-based judges. To make this question measurable, we construct PointRubric and RaR-Science-Static, two pointwise rubric-based evaluation datasets with instance-specific criteria and itemwise satisfaction labels. We compare three ways of extracting criterion-level judgments from small models: Generative verdicts, Yes/No Logprob margins, and Probe judges. Across both datasets, the Qwen3-1.7B Probe judge achieves the strongest criterion-level agreement among these methods, outperforming Generative and Logprob judges. Used as a GRPO reward model, it trains a policy from 0.232 to 0.643 on RaR-Science rubric score, compared with 0.594 for an 8B Generative judge baseline, while the baseline requires 10.7$\times$ more reward-judge time. Task and domain transfer experiments further suggest that Probe judges preserve criterion-level reward structure across settings.
Feng-Yu Xie, Yilun Zhao, Bingsen Chen et al.· 0 citations
We introduce MMSciCode, a comprehensive expert-level, multilingual multi-discipline benchmark for evaluating foundation models in scientific code generation. It includes 624 expert-annotated research coding problems spanning six core scientific disciplines. Compared to prior benchmarks, MMSciCode features three key advancements. First, it challenges models to integrate domain-specific knowledge with algorithmic reasoning to implement core functions from research papers. Second, each problem is meticulously annotated by domain experts through a rigorous paper-grounded process, with strict quality controls implemented to ensure dataset integrity and authenticity. Finally, each problem is equipped with comprehensive unit test suites and con-tainerized environments, enabling reproducible and diagnostic evaluation of both functional correctness and domain validity. We conduct an extensive evaluation of 23 state-of-the-art foundation models and 2 coding agents on MMSciCode. We identify substantial performance gaps between models and human experts, providing actionable insights for advancing expert-level scientific code generation.
Xue Xia, Zheyuan Yang, Arman Cohan et al.· Annual Meeting of the Associ...· 1 citation