False negative
A real case that a check or matching step failed to flag: two records for the same customer left unmatched, or a wrong value that passed validation.
False negatives are the quiet kind of error, because nothing draws attention to them. Finding them means examining a sample of what was not flagged.
Where it comes up
- Near-duplicate recordsTwo rows describe the same real thing but differ enough that an exact comparison misses them.
- The same entity in two systemsOne person or organization exists in two systems under different identifiers, with nothing linking the records.
See also
- False positiveA case that a check or matching step flagged wrongly: two different people treated as one, or a correct value reported as an error.
- Match thresholdThe similarity score at or above which two records are treated as the same thing. Pairs scoring below it are left as separate records.
- SamplingExamining a subset of the rows in place of all of them, either to get a quick picture of a dataset or to check the result of a change by hand.