Review: Reinforcement Learning Basics

Reinforcement learning is a mathematical framework.

Demystify the reinforcement learning model, it’s a open-ended model using reward function to optimize agent to solve complex task in target environment.

Step by Step

For RLHF training method, here are three core steps:

  1. Pretraining a language model
  2. Gathering data(问答数据) and training a reward model
  3. Fine-tuning the LM with reinforcement learning

Step 1. Pretraining Language Models

Read this to learn how to train a LM:

Pretraining language models

OpenAI used a smaller version of GPT-3 for its first popular RLHF model - InstructGPT.

Nowadays, RLHF is new area, there’s no answer to which model is the best for starting point of RLHF and using expensive augmented data to fine-tune is not necessarily.

Step 2. Reward model training

In reward model, we integrate human preferences into the system.

Reference