Source · paper
Training language models to follow instructions with human feedback
Summary
Describes InstructGPT: a pre-trained model fine-tuned on human demonstrations, then optimised with reinforcement learning from human feedback (RLHF) using a reward model trained on human rankings of outputs.
Key points
- Three stages: supervised fine-tuning, reward model training, RL optimisation (PPO).
- A 1.3B InstructGPT model was preferred by raters over the 175B base GPT-3.
- Alignment training improves helpfulness and truthfulness at small cost to benchmarks.
Why it matters
Established the post-training recipe behind chat assistants; later methods (RLAIF, constitutional training, DPO, RL with verifiable rewards) build on or replace parts of it.