Definition
Chain-of-Thought (CoT) prompting is a technique that forces a language model to break down its reasoning into intermediate steps before producing the final answer. Two variants exist. Zero-shot CoT adds 'Let's think step by step' to any prompt. Few-shot CoT includes 1-3 worked examples showing the reasoning chain. CoT lifts accuracy 30-71% on math, logic, and code reasoning tasks. It does not help on simple lookups or creative writing.
Example
'A store had 23 apples. They sold 15, received 38, sold 27. End-of-day count? Let's think step by step.' Output walks through each arithmetic step, then gives the answer 19.
When to use
Multi-step reasoning, math word problems, logic puzzles, code debugging, multi-criteria decisions.
Also known as
cot, chain of thought