Building OpenAI o1
OpenAI. Three minutes with the o1 team describing the moment the model started questioning its own reasoning during RL training. Useful as the primary source for the article's claim that the chain-of-thought is now happening inside the model, not in your prompt.
AI Expert note
Keep this as historical source material, not as current implementation guidance. It explains why the category emerged, but production choices should be based on the current model lineup and API docs.
What you should get from this
See the original product/research framing that made reasoning models different from ordinary chat models.
Watch or know first
Watch the primary pick first or read the companion article's reasoning-model section.
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Continue through the same learning path with the next curated companion videos.
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