Accumulate anomalies on a running list — trigger schema…
Accumulate anomalies (observations that don't fit the schema) in a running list and trigger full schema review when the count reaches a pre-defined threshold, rather than treating each anomaly as requiring immediate action.
When This Fires
- When an observation doesn't fit your current schema but isn't dramatic enough to warrant immediate review
- During any ongoing schema monitoring when individual anomalies feel ambiguous
- When you want to balance responsiveness with stability in schema management
- Complements Pre-commit to prediction failure thresholds (X out of Y)… (prediction failure thresholds) with an anomaly-based trigger
Common Failure Mode
Explaining away each anomaly individually: "This one was unusual circumstances. That one was an edge case. The other one was bad data." Each explanation is plausible in isolation. But 5 individually-explained anomalies might share a common cause that only becomes visible when you look at the set rather than each one independently.
The Protocol
(1) Create a running anomaly list for each important schema. (2) When an observation doesn't fit → log it: date, what you expected, what happened, which schema was involved. Do NOT investigate or revise the schema yet. (3) Set a threshold (default: 5 anomalies). (4) When the threshold is reached → trigger full schema review. Look at the accumulated anomalies as a set: do they share a pattern? Point to a common cause? Reveal a systematic boundary condition? The set analysis produces insights that individual anomaly analysis cannot.