Consistency
Whether data agrees with itself: the same fact written the same way everywhere, and related values that do not contradict each other.
It covers format, such as one date style throughout, and logic, such as a ship date that is not earlier than the order date. Data can be consistent and still be wrong.
Where it comes up
- Inconsistent category labelsA column meant to hold a few fixed values holds many spellings of them.
- Mixed date formatsOne column holds dates written in several different styles.
- Inconsistent capitalizationThe same value appears in capitals, in lowercase, and in mixed case, and software treats each as different.
See also
- StandardizationRewriting values so that everything of one kind follows one format: every date year first, every phone number in the same pattern.
- Data qualityHow well a dataset serves the purpose it is used for. Usually judged by accuracy, completeness, consistency, validity, uniqueness, and timeliness.
- Canonical valueThe one agreed spelling for a thing that can be written several ways, such as VA for Virginia, virginia, and Va.