SELF-REDRAFT: Eliciting Intrinsic Exploration-Exploitation Balance in Test-Time Scaling for Code Generation
Yixiang Chen, Tianshi Zheng, Shijue Huang, Zhitao He, Yi R. Fung
TL;DR
Self-Redraft tackles the problem of achieving an intrinsic balance between exploration and exploitation in test-time scaling for code generation without execution feedback. It extends Self-Refine by explicitly prompting drafting when flaws are detected, enabling a hybrid search strategy under an execution-free setting. On LiveCodeBench across six models, Self-Redraft yields modest gains over Self-Refine but does not reach the potential suggested by the pass@8 upper bound, highlighting gaps in the model's self-guided exploration. The study identifies bottlenecks in feedback quality and discriminative judgment, reveals model-specific balancing behavior, and establishes a baseline for future work in improving critique, adaptation, and exploration strategies for robust, real-world code generation.
Abstract
Test-time scaling without interpreter feedback is essential for real-world code generation scenarios where test cases are not readily available. While existing paradigms often rely on either greedy exploitation (i.e., iterative refinement) or stochastic exploration (i.e., relying on sample-based voting or reranking mechanisms), the balance between these two dimensions remains underexplored. To investigate the LLM's intrinsic ability to balance exploitation and exploration, we introduce SELF-REDRAFT, a framework built upon Self-Refine that encourages the model to propose new drafts for solutions that are fundamentally flawed. Our results show that SELF-REDRAFT consistently achieves better performance than Self-Refine when converged under the same maximum number of iterations. Still, we observe that significant room for improvement remains, largely due to two core aspects of current self-redraft capabilities: constrained capacity for generating instructive feedback and fragile discriminative judgment. We also find that balancing strategies vary notably across different LLMs, reflecting distinct, model-specific behaviors. Overall, our study establishes a baseline for intrinsic exploration-exploitation balancing in test-time scaling and identifies feedback and discrimination as key areas with potential for future advances.
