Worked review cases
A metric is only the beginning.
Four illustrative reviews connect inputs, calculations, limitations and decisions.
Data qualityDrift & stabilityOutcome reviewChange control
Twenty rows, nineteen periods: a quality escalation
A synthetic monthly batch has the expected row count but contains a duplicate, a missing period, null cells and stale delivery metadata.
A distribution change that warrants review
Reproduce a PSI of 0.202499 from fixed bins, additive smoothing and twenty synthetic observations, then interpret its limits.
A complete window can still require a drawdown review
Compare two synthetic twenty-month return paths using compounding, paired active returns, tracking error and drawdown from the initial wealth point.
Changing a threshold does not resolve a finding
Replay the same synthetic drift input under two valid policies and retain a fictional decision record explaining why a quieter status is insufficient.