# Data trust check · [Report or analysis] · [Date] Run before any number drives a decision. Record failures before the answer, not after. | Check | Question | Result | Action if failed | |---|---|---|---| | Freshness | When was each source last updated? Is that later than the decision needs? | | | | Quality | Are null, duplicate or out-of-range rates unusual? | | | | Volume | Did event or row counts move outside the normal range? | | | | Schema | Did any field, event name or definition change in the last 30 days? | | | | Lineage | Which upstream sources feed this number? Did any have a problem? | | | | Definition | Which dictionary entry and version was used? | | | | Denominator | What's the base, and how many accounts does it contain? | | | | Hand check | Does one named account reconcile across sources? | | | **Verdict:** Trust / Trust with caveats (list) / Don't use yet