vamseeachanta Completeness Score (+3)
Completeness Score
Rate each column:
- Complete (>99% non-null): Green
- Mostly complete (95-99%): Yellow -- investigate the nulls
- Incomplete (80-95%): Orange -- understand why and whether it matters
- Sparse (<80%): Red -- may not be usable without imputation
Consistency Checks
Look for:
- Value format inconsistency: Same concept represented differently ("USA", "US", "United States", "us")
- Type inconsistency: Numbers stored as strings, dates in various formats
- Referential integrity: Foreign keys that don't match any parent record
- Business rule violations: Negative quantities, end dates before start dates, percentages > 100
- Cross-column consistency: Status = "completed" but completed_at is null
Accuracy Indicators
Red flags that suggest accuracy issues:
- Placeholder values: 0, -1, 999999, "N/A", "TBD", "test", "xxx"
- Default values: Suspiciously high frequency of a single value
- Stale data: Updated_at shows no recent changes in an active system
- Impossible values: Ages > 150, dates in the far future, negative durations
- Round number bias: All values ending in 0 or 5 (suggests estimation, not measurement)
Timeliness Assessment
- When was the table last updated?
- What is the expected update frequency?
- Is there a lag between event time and load time?
- Are there gaps in the time series?