Reward the Recheck: Reflection as a Control Surface for Reasoning Post-Training
TL;DR for operators Zhijie Wang’s GRPO and Reflection Reward for Mathematical Reasoning in Large Language Models1 offers two practical signals for teams tuning reasoning models. First, additional post-training stages do not compose automatically. On Qwen2.5-Math-7B, the base model scores 58.6% on MATH-500, supervised fine-tuning reaches 66.2%, and reinforcement learning applied directly to the base model reaches 73.8%. Yet the model that receives supervised fine-tuning before reinforcement learning falls to 57.6%. The authors attribute this weakness mainly to differences in the size and distribution of the datasets used at the two stages. ...