How Reinforcement Learning from Human Feedback (RLHF) works.
RLHF is the technique that makes LLMs helpful, harmless, and honest. After initial pre-training on text data, models are further trained using human evaluators who rank outputs. A reward model learns these human preferences, and the language model is optimized to produce outputs that score highly.
This is why ChatGPT feels different from a raw language model. Without RLHF, a model might generate toxic content, refuse to answer, or produce unhelpful responses. With RLHF, it learns to be conversational, follow instructions, decline harmful requests, and admit uncertainty. Anthropic uses a related technique called RLAIF (RL from AI Feedback) along with Constitutional AI.
For builders, RLHF matters because it explains model behavior patterns. When a model refuses a request, that is RLHF training. When it says "I don't know" instead of hallucinating, that is RLHF. Understanding this helps you write better system prompts that work with (not against) the model's alignment training.
Where it helps.
- 01Understanding model behavior and limitations
- 02Safety and alignment in AI products
- 03Building trust in AI outputs
- 04Designing effective system prompts