Consistency

Definitions

Relation

Consistency is a characteristic of related data values

Examples

Inconsistancy within a record
Adress Postcode City
Veldweg 11 8051 NK Hattem

Postcode doesn't match with adress.
Data quality rule: The postcode matches the address according to the postcode table

Inconsisteny within a file
ID Customer City name
248 Johson Alphen aan den rijn
2342 Smith Alphen a/d rijn

Different spelling of city name.
Data quality rule: City names are spelled out in a uniform manner.

Inconsistency between two files
ID Initials Name
4320 T Sanders
ID Initials Name
4320 T.M.D Sanders

Inconsistency: Different initials of the same customer.
Data quality rule: Initials of the same person are the same.

Inconsistency over time
License plate Date Mileage
123-RT-97 6 March 2020 60,543
123-RT-97 8 May 2021 45,765

Inconsistency: Mileage decreases over time.
Data quality rule: Maileage increases over time or remained the same.

Reference

DAMA NL (2020). Dimensions of Data Quality (DDQ). Research paper. https://www.dama-nl.org/wp-content/uploads/2020/09/DDQ-Dimensions-of-Data-Quality-Research-Paper-version-1.2-d.d.-3-Sept-2020.pdf