Rejection Sampling Fine-Tuning: How Filtering Model Outputs by Reward Replaced RLHF Complexity
Rejection Sampling Fine-Tuning: How Filtering Model Outputs by Reward Replaced RLHF Complexity Rejection sampling fine-tuning (RAFT) has emerged as the practical workhorse of LLM alignment. While PPO-based RLHF dominated early literature, production systems from Llama 2 to DeepSeek-R1 rely on a simpler loop: generate multiple completions per prompt, score them with a reward model, keep the best, and fine-tune on the filtered data. The technique converts the reinforcement learning problem into s
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