Haotian Ye, Haowei Lin, Jingyi Tang, Yizhen Luo, Caiyin Yang, Chang Su, Rahul Thapa, Rui Yang
Language models are increasingly used in scientific discovery to generate hypotheses, propose candidate solutions, implement systems, and iteratively refine them. At the core of these trial-and-error loops lies evaluation: the process of obtaining feedback on candidate solutions via verifiers, simulators, or task-specific scoring functions. While prior work has highlighted the importance of evaluation, it has not explicitly formulated the problem of how evaluation-driven discovery loops can be scaled up in a principled and effective manner to push the boundaries of scientific discovery, a problem this paper seeks to address. We introduce Simple Test-time Evaluation-driven Scaling (SimpleTES), a general framework that strategically combines parallel exploration, feedback-driven refinement, and local selection, revealing substantial gains unlocked by scaling evaluation-driven discovery loops along the right dimensions. Across 21 scientific problems spanning six domains, SimpleTES discovers state-of-the-art solutions using gpt-oss models, consistently outperforming both frontier-model baselines and sophisticated optimization pipelines. Particularly, we sped up the widely used LASSO algorithm by over 2x, designed quantum circuit routing policies that reduce gate overhead by 24.5%, and discovered new Erdos minimum overlap constructions that surpass the best-known results. Beyond novel discoveries, SimpleTES produces trajectory-level histories that naturally supervise feedback-driven learning. When post-trained on successful trajectories, models not only improve efficiency on seen problems but also generalize to unseen problems, discovering solutions that base models fail to uncover. Together, our results establish effective evaluation-driven loop scaling as a central axis for advancing LLM-driven scientific discovery, and provide a simple yet practical framework for realizing these gains.
This paper introduces SimpleTES, a framework that formalizes and scales evaluation-driven discovery loops for LLM-based scientific discovery. The key insight is that the evaluation budget N can be decomposed into three orthogonal dimensions: global width C (parallel independent trajectories), refinement depth L (iterative feedback-driven improvement), and local sample size K (best-of-K selection at each step). The paper argues—and demonstrates empirically—that principled allocation across these dimensions is as important as scaling model capability itself.
The framework is complemented by RPUCG, a graph-based context construction method for selecting historical nodes to include in prompts, and a trajectory-level post-training approach that trains models on successful discovery trajectories rather than individual step rewards.
The central problem addressed is important: while many systems use evaluation-driven loops (AlphaEvolve, OpenEvolve, TTT-Discover, etc.), none had explicitly formulated the scaling question—how to allocate evaluation queries optimally across exploration, refinement, and selection dimensions.
Immediate practical impact: The results are genuinely impressive across domains:
Broader influence: The paper's greatest contribution may be conceptual—establishing that evaluation-driven loop scaling is a "central axis" for LLM-driven discovery, distinct from model scaling or reasoning-token scaling. This reframing could redirect research effort toward better evaluator design and budget allocation strategies.
Adjacent fields: The framework naturally extends to any domain with programmatic evaluators: drug discovery (docking scores), materials science (DFT calculations), compiler optimization, etc.
This paper arrives at a critical inflection point. Multiple groups (Google DeepMind's AlphaEvolve, Together AI, TTT-Discover) have demonstrated impressive results with evaluation-driven discovery, but each uses different, often complex, system designs. SimpleTES's contribution is to distill these into a clean, analyzable framework and show that much of the complexity may be unnecessary—the three-dimensional budget allocation (C, L, K) captures most of the scaling behavior.
The demonstration that open-source models with principled evaluation scaling can match or exceed frontier models with sophisticated pipelines is particularly timely given concerns about compute inequality in AI research.
Reproducibility: The paper provides detailed hyperparameters, evaluation protocols, and prompts (Appendix E), supporting reproducibility. However, the reliance on gpt-oss models (specific OpenAI models) may limit exact replication.
This is a high-impact systems paper that makes a compelling case for evaluation-driven scaling as a first-class research direction. Its breadth of empirical validation is exceptional, and the conceptual clarity of the (C, L, K) decomposition provides a useful lens for the field. The main limitations—fixed budget allocation, dependence on good evaluators, and relatively simple theoretical grounding—represent natural directions for future work rather than fundamental flaws.
Generated Apr 22, 2026