Which data quality control measure helps identify incorrect values in a field that stores customer IDs in a defined format?

• A. Outliers
• B. Validation
• C. Redundancy
• D. Completeness

Answer: (B)

Validation is the measure that ensures data values conform to a defined format and data type. For a field that stores customer IDs, which must follow a specific pattern, validation checks verify aspects like length, allowed characters, and the overall pattern (for example, a prefix plus digits or a UUID-like structure). When a value doesn’t match the required format, it is flagged for correction, so only correctly formatted IDs are stored.

Outliers focus on values that deviate from typical ranges and aren’t designed to enforce a particular format. Redundancy looks for duplicate records, not whether an individual field matches its required pattern. Completeness checks whether values are present, but it doesn’t verify that the present values follow the defined format. Validation directly targets the format rule, making it the best fit for identifying incorrect IDs.