Stepwise Credit Assignment for GRPO on Flow-Matching Models

1. 1Identify the temporal structure of diffusion generation in flow models
2. 2Assign credit based on the composition and content determined by early steps
3. 3Assign credit based on the details and textures resolved by late steps
4. 4Implement stepwise credit assignment in GRPO to improve flow-matching models

ML researchers and engineers working on reinforcement learning and flow models can benefit from this approach to improve model performance and efficiency

💡 Uniform credit assignment can inadvertently reward suboptimal intermediate steps, while stepwise credit assignment considers the temporal structure of diffusion generation

💡 Stepwise credit assignment boosts flow-matching models