Survey: RL vs Online Policy Distillation vs SFT

Author: @neural_avb | Date: 2026-05-01

Recommendation of a survey comparing reinforcement learning, online policy distillation (OPD), and supervised fine-tuning (SFT) for LLM alignment and capability improvement. Described as worth a full 30-minute read.

Key Claims

  • Survey systematically compares RL, OPD, and SFT approaches
  • Each method has distinct tradeoffs in sample efficiency, stability, and final quality
  • Online policy distillation emerging as middle ground between RL and SFT
  • Understanding when to use each is critical for LLM training pipelines

Takeaways

  • The post-training landscape is more nuanced than “just do RLHF”
  • OPD (distilling from a policy trained with RL) can capture RL benefits without RL instability
  • SFT remains strong baseline but has ceiling effects
  • Practitioners should read this to choose the right post-training strategy

Linked Concepts