Double entry

Verification

Validation

Length check

Format check

Presence check

Range check

Presence check

Check digit

Format check

Length check

Presence check

Length check

Format check

Check digit

Length check

Format check

Range check

310921

211113

21st June 2004

Validation can check that the data is sensible

Validation can check that the data falls between certain allowable boundaries

Validation can check that the data is correct

Double entry - typing the data in twice and getting the computer to check the second version against the first

Using presence, range and length checks to make sure that no mistakes happen

Printing out what you have typed in and comparing it against the source data

Presence check

Format check

Lookup