Definition
Plain language
When a model writes out its reasoning step by step before giving an answer.
As stated in the literature
A prompting and generation strategy where the model produces intermediate reasoning tokens before its final answer, often improving accuracy on multi-step tasks.
Also called: CoT, chain-of-thought, chain-of-thought reasoning, chains of thought
Why it matters: Letting the model spend tokens on intermediate steps often turns problems it would otherwise fumble into ones it can solve reliably.
For example, asked how many tennis balls fit in a suitcase, the model writes out estimates of a ball's volume and the suitcase's volume before giving a final number.
Heard on the show
“Not a metaphorical one — a literal cascade of all-caps reasoning where it's screaming at itself in its own chain of thought.”Episode 006 — What Happens Inside Claude When It Decides to Blackmail Someone