Glossary
Test-Driven Development (for AI)
An approach to AI product development where evaluation criteria and test cases are defined before prompts or models are changed, so success can be measured objectively.
Test-driven development (TDD) is a software engineering practice adapted for AI work: instead of making a change and then checking whether it helped, you define what “better” means — in the form of specific test cases and success criteria — before you start experimenting. This prevents the common trap of judging success by how the model “feels” after a change rather than by whether it actually solved the problem you set out to solve. For example, if users are complaining that the model is too verbose, you’d first write a set of test cases that represent the problematic pattern, define what a better response looks like, and only then begin adjusting prompts or training data. For behavior architects, test-driven thinking is a discipline that forces clarity about goals and makes improvement legible.