Paper Overview
Field: NLP Authors: Tong Zheng, Haolin Liu, Chengsong Huang Published: 2025-05-07 arXiv: 2505.05128
Abstract
Test-time scaling (TTS) has become an effective approach for improving large language model performance by allocating additional computation during inference. However, existing TTS strategies are largely hand-crafted: researchers manually design reasoning patterns and tune heuristics by intuition, leaving much of the computation-allocation space unexplored.
The authors propose an environment-driven framework, AutoTTS, that changes what researchers design: from individual TTS heuristics to environments where TTS strategies can be discovered automatically.
Key Ideas
- Environment construction is central: the discovery environment must make the control space tractable and provide cheap, frequent feedback for TTS search.
- Width–depth TTS as controller synthesis: TTS is formulated as synthesizing a controller based on pre-collected reasoning traces and probe signals. The controller decides when to branch, continue, probe, prune, or stop, and can be evaluated cheaply without repeatedly calling the LLM.
- Beta parameterization is introduced to make the search tractable.
- Fine-grained execution-trace feedback helps the agent diagnose why candidate TTS programs fail, improving discovery efficiency.
- Discovered strategies outperform strong hand-designed baselines in accuracy–cost trade-offs on mathematical reasoning benchmarks.
- The discovered policies generalize to held-out benchmarks and model scales.
- The entire discovery process cost only $39.9 and took 160 minutes.
- arXiv: https://arxiv.org/abs/2505.05128