Instruction design and structured outputs · Module 1: Instruction design and structured outputs in practice
Structured output is only the first check
Learning outcome: Distinguish valid shape from correct content.
A structured response uses a predictable shape, such as fields in a JSON object or columns in a table. A schema can constrain names, types and allowed values. It cannot establish whether an amount is accurate or whether an action is authorised.
Check output in layers: can it be parsed, does it meet the schema, and do the values agree with the source and business rules? Define how unknown values should be represented. An explicit null or “not supplied” can be more useful than a guessed date. Treat a validation failure as a reason to pause or repair the output before another system acts on it.
Worked example
A fictional request needs amount, currency and approval status. The source says “£240 requested; manager has not decided.” A valid-looking output with amount 240, currency GBP and status approved has the right shape but the wrong decision. A separate source check must reject it even if every field passes the schema.
Try it yourself
Define fields for a purchase request and three permitted approval states. Create one malformed response and one well-formed response with a false approval. Explain which check catches each.
You can do this exercise on paper. If using an assistant, keep to the fictional material and an approved tool.
Compare your approach
A parser catches malformed syntax. Schema validation catches an unsupported state label. The false approved value needs comparison with the source or an authoritative approval record; syntax alone cannot catch it.
Check your understanding
A response passes its JSON schema. What does that establish?
- Every factual value is verified
- Any requested action is authorised
- Its structure meets the schema, not that its claims are true
Show the answer and explanation
Answer: Its structure meets the schema, not that its claims are true. A schema checks structure and permitted values. A false approval can still have a valid field name and type, so source and authorisation checks remain necessary.
Workbook
Download the course workbook to record your answer and compare it after the knowledge check.