The Sequence Knowledge #800: Not All World Models are Created Equal

A taxonomy to understand world models.

800 issues of The Sequence! What a run! Go subscribe for the next 800!

Today we will Discuss:

1. An overview of the different types of world models.

2. A discussion about the first major paper about world models.

💡 AI Concept of the Day: Not All World Models are Created Equal

For decades, the dominant paradigm in Reinforcement Learning (RL) was “Model-Free.” In this approach, an AI agent is essentially a reactive machine. It observes a state, takes an action, and receives a reward.¹ If the action was good, it statistically reinforces that behavior. It does not understand why the action was good, nor does it possess an internal map of the environment. It is comparable to a reflex: touching a hot stove and pulling away requires no understanding of thermodynamics, only a nervous system that registers pain.