Data Validation & Verification (1.3.f)
Data validation checks that information provided is reasonable, for example:
- Presence Check - has the form field been filled?
- Length Check - is the data of a reasonable length? For example, is the postcode 6 or 7 characters long.
- Format Check - is the data in the correct format? For example, a date might need to be of the form dd/mm/yyyy.
- Range Check - is the data within the correct range? For example, to book a hotel room, a date mustn't be in the past.
- Existence Check - does the data match a previous value? For example, does the username for a new registration match an existing username, or does the make of car given match a known make of car?
Verification is about checking that data is correct and consistent. For example, typing an email address or password twice to make sure it isn't typed incorrectly. Data can also be checked visually - for example checking OCR data against the actual document.