Q16 of 21 · AI for testing
You've adopted an AI test-generation tool — how do you measure whether it's actually helping?
Short answer
Short answer: Measure time-to-first-runnable-test, defect escape rate in AI-covered areas, the correction rate per generated test, and false-confidence rate (tests that pass but miss real regressions). Tests generated per week is an output metric — it says nothing about quality.
Detail
The common trap: teams adopt an AI tool, measure tests generated per week, and call it a success. That is an output metric, not an outcome metric.
Meaningful metrics: Time-to-first-runnable-test: does AI actually save time compared to writing from scratch, or is the review and correction cycle taking the same time? Measure this for the same test type before and after adoption with real engineers. Defect escape rate for AI-covered areas: are bugs still reaching production in features where AI generated the tests? A high escape rate signals the tests are vacuous. Correction rate per generated test: track how often engineers make non-trivial changes before committing. A 90% correction rate means the tool is generating noise, not value. False-confidence rate: run mutation testing on a sample of AI-generated tests. What percentage of seeded faults do the tests actually catch? This directly measures assertion quality.
Set a 60-day review checkpoint before committing to the tool long-term. If outcome metrics haven't improved, the tool is adding overhead, not value.