6arXiv cs.CL (Computation and Language)·
SERPO: Self-evolving rubric policy optimization enables test-time RL for open-ended generation
SERPO (Self-Evolving Rubric Policy Optimization) is a new method for test-time reinforcement learning that extends self-evolution to open-ended generation tasks without requiring labeled feedback, external reward models, or stronger judge models. The approach co-evolves response archives, query-specific rubrics, and policy parameters in a closed loop using a Good-Normal-Bad response organization scheme and probabilistic criterion scoring. Evaluated across six benchmarks, SERPO improves HealthBench and ResearchQA by up to 20.63 and 20.31 points over base models and raises the macro-average by up to 8.06 points. The method addresses a key limitation of existing TTRL approaches that rely on answer voting and cannot generalize to tasks without canonical answers.
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POW3R: Policy-Aware Rubric Rewards for More Efficient RLVR Training
This paper identifies a failure mode in rubric-based reinforcement learning with verifiable rewards (RLVR): static aggregation of criterion weights conflates human-assigned importance with current optimization utility, causing many criteria to be either already saturated or unreachable. The authors introduce POW3R, a framework that dynamically reweights criterion-level rewards during training using rollout-level contrast to emphasize criteria that currently differentiate policy outputs. Across three base policies and two datasets (multimodal and text-only), POW3R wins 24 of 30 comparisons on rubric reward and strict completion metrics, and reaches equivalent performance in 2.5–4× fewer training steps than vanilla GRPO with rubric rewards.
SCOPE: Self-Play via Co-Evolving Policies for Open-Ended Tasks
SCOPE is a data-free self-play framework for training language models on open-ended tasks without external supervision or frontier-model judges. It co-evolves two policies—a Challenger that generates document-grounded tasks and a Solver that answers via multi-turn retrieval—using a frozen copy of the initial model as a self-judge that writes task-specific rubrics. Across three 7-8B models (Qwen2.5, Qwen3, OLMo-3), SCOPE achieves up to +10.4 points on eight open-ended benchmarks and +13.8 points on seven held-out short-form QA benchmarks, matching or exceeding GRPO trained on ~9K curated prompts. Ablations identify rubric generation quality as the primary bottleneck for self-judging.
QUBRIC: Co-designing queries and rubrics for RL beyond verifiable rewards
QUBRIC is a framework that jointly optimizes queries and rubrics for reinforcement learning in settings where rewards are not strictly verifiable. The approach uses teacher-derived key points to rewrite open-ended queries into evaluable scenarios, applies contrastive rubric generation to capture teacher-policy gaps, and filters for learnability before GRPO training. Trained only on instruction-following data, QUBRIC achieves a +5.5 point gain on ArenaHard over an SFT baseline and transfers to legal, moral, and narrative reasoning benchmarks (+6.3 points average), suggesting rubric-based RL can complement RLVR in non-verifiable domains.
Rubrics on Trial: Self-evolving evaluation rubrics from a single query via synthetic pairwise evidence
A new arXiv preprint introduces 'Rubrics on Trial,' a query-only framework that automatically constructs and validates evaluation rubrics for LLMs without external annotations or model training. The system evolves rubric sets from scratch using synthetic rubric-conditioned response pairs, screening out non-discriminative, over-specific, or style-only rubrics. Evaluated across five preference benchmark suites, it achieves best average accuracy and leads on six of seven evaluation sets, addressing a key bottleneck in scalable LLM evaluation.
DeepRubric: Evidence-tree rubric supervision cuts RL training cost for deep research agents by 13x
DeepRubric is a data construction framework that improves reinforcement learning efficiency for deep research agents by reversing the typical rubric-generation process: rather than inferring evaluation criteria from a query, it builds an evidence tree of verifiable sub-questions first, then synthesizes aligned query-rubric pairs. The authors construct 9K training examples and train DeepRubric-8B using rubric-based GRPO, achieving comparable performance to prior open-source state-of-the-art deep research models on three benchmarks while using roughly 13x fewer RL GPU-hours. The work addresses a key bottleneck in RL-based training of long-form research agents: unreliable reward signals from incomplete rubrics.
GraphPO: Graph-based Policy Optimization reduces redundancy in LLM reasoning RL
GraphPO is a new reinforcement learning framework that represents reasoning rollouts as directed acyclic graphs rather than independent chains or trees, merging semantically equivalent reasoning paths into equivalence classes to share suffixes and reduce redundant exploration. The approach assigns efficiency advantages to incoming edges and correctness advantages to outgoing edges, deriving process supervision from outcome rewards. Experiments on three LLMs across reasoning and agentic search benchmarks show consistent improvements over chain- and tree-based baselines under equal token or response budgets. The method also provides theoretical guarantees on reduced advantage-estimation variance.
Rubric-Conditioned Self-Distillation: structured feedback for reasoning model post-training
A new arXiv preprint proposes Rubric-Conditioned Self-Distillation (RCSD), a post-training framework that replaces scalar reward signals and noisy chain-of-thought annotations with structured rubrics for fine-grained credit assignment. The method conditions a teacher model on criterion-level rubrics to provide token-level guidance on the student's own sampled trajectories, avoiding reliance on a single reference rationale. Evaluated on science reasoning benchmarks, RCSD outperforms GRPO by 1.0 points and OPSD by 0.9 points on average.
RLAES: Reinforcement learning framework for joint essay scoring and feedback generation with rubric rewards
Researchers propose RLAES, a unified LLM framework that jointly optimizes automated essay scoring (AES) and feedback generation via reinforcement learning. The system introduces Rubric-based Feedback Evaluation (RFE) with 166 fine-grained binary rubric items and an LLM-as-judge, plus Adaptive Gated Feedback Optimization (AGFO) and Adjacent Contrastive Reasoning (ACR) for score calibration. On the ASAP benchmark, RLAES-AGFO achieves QWK=0.803 among LLM-based methods while maintaining feedback quality comparable to GPT-5.5. Code and datasets are publicly released.