What is an A/A test and why run it?
mediumAnswer
- Both variants receive the SAME model.
- Expected result: no significant difference (~5% false-positive rate).
- Uses: (1) validate experimentation platform (SRM, randomization correctness).
- (2) baseline noise level for the metric.
- (3) sanity check before running A/B (ensure no accidental config difference).
- Run periodically.
- Standard practice at Airbnb, Booking, Microsoft.
- Failure = broken platform, don't trust any results until fixed.
Check yourself — multiple choice
- Random
- Both variants = same model; expect no significant diff (~5% FP); validates platform + baseline noise + sanity check before A/B; run periodically; failure = broken platform
- Same as A/B
- Not real
A/A test: sanity-check platform; expect no diff; run periodically.
#experimentation
Practise MLOps & Data Quality
215 interview questions in this topic.