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Prompt Decomposition

Decomposition is what you do BEFORE writing the prompt, then encode IN the prompt. You look at the task, identify its N sub-problems, and write instructions that address each one in a specific order.

Distinct from prompt chaining (which splits across API calls) and chain-of-thought (which asks the model to reason step by step). Decomposition front-loads the structure: "First X, then Y, then combine into Z." The model doesn't have to discover the decomposition; you hand it over.

Example

Evaluate this customer feedback.

Address these four sub-questions in order:
1. What is the customer's specific complaint?
2. Is this a product issue, a service issue, or a policy issue?
3. What is the minimum action needed to resolve it?
4. What is the optimal action to delight the customer beyond resolution?

Produce a one-paragraph summary only after you've worked through 1-4.

When to use it

  • Complex tasks where the model has been picking the wrong decomposition
  • You know the sub-problems better than the model
  • You want the output to cover specific dimensions every time

When not to use it

  • Simple tasks where the decomposition is obvious
  • You don't actually know the sub-problem structure (let the model try first)
  • The "decomposition" is really a laundry list of "also do these 10 things"