AI Vocabulary · 01 The Model
What is World Model?
An AI model that predicts how an environment changes when someone acts in it, so it can simulate and plan.
A world model takes the current state of an environment and an action and predicts what happens next. Fei-Fei Li describes the goal as models that generate consistent worlds, take many kinds of input and react to actions. Google DeepMind lists Genie 3 as a world model.
The term has no agreed definition yet. Melanie Mitchell notes that researchers disagree on whether today's language models already build world models inside or mostly retrieve patterns from their training data.
Why it matters for you
World models are where much new money goes. Li's World Labs and Yann LeCun's AMI Labs build their companies on them, arguing that text-only models cannot handle space and physics well. For robotics, design, AR and VR, the topic decides which model you need.
Own it
If your product deals with physical space, distances or movement, test a text model on exactly those tasks before you rely on it. Multimodal input alone does not guarantee spatial understanding.
Where it comes from
Fei-Fei Li sets out the idea in From Words to Worlds: Spatial Intelligence is AI's Next Frontier (2025). Melanie Mitchell discusses the open questions in LLMs and World Models, Part 1 (2025).
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