Lesson 9 of 10
Evaluate a Prompt
A prompt is good when it works repeatedly on representative inputs, not when one demo looks impressive.
Active reading
Understand the idea
Create a small test set containing normal cases, difficult cases and missing-information cases. Compare outputs against clear criteria such as correctness, completeness and format compliance.
Example
Test the same extraction prompt on 10 emails instead of judging it from one clean email.
Practice
Apply this lesson to one real task you already have, then write down how you would verify the result.
Common mistake
Changing the prompt after every single failure without checking whether the change hurts other cases.
Key takeaway
Evaluate prompts like small programs: with repeatable tests and explicit success criteria.