Data Validation and Verification WJEC ICT GCSE
Task 1: Definitions Write a definition for each of these terms: Data Validation A check performed by a computer program during data entry. Data Verification Means checking the data being entered into the system perfectly matches the source of the data.
Task 3: Fill in the missing words • Validation checks are used to restrict the data a user can enter. • verification means checking that the data being entered perfectly matches the source of the data. • Validation aims to ensure that data is complete, responsible and sensible. • A type check could be used to make sure that only numerical data could be entered. • A format check could be used to ensure the correct entry of a postcode. • A presence check could be used to ensure that a field is not left blank.
Task 4: Data Validation • What is meant by check digit? • Give 2 different examples where check digits are used. An extra number added to the end of a long number which is calculated from all the other numbers and is used to ensure that the number has been input correctly. ISBN BARCODES
Task 5: Data Validation • Here are some dates of birth that are to be entered into an ICT system: • 12/01/3010 • 01/13/2000 • 30/02/1999 • Assume all dates are in the format dd/mm/yyyy. For each one explain why they cannot be valid dates of birth. The year 2010 is in the future. There’s only 12 months. The isn’t 30th days in February.
Task 6: Data Validation • Employees are given a employee code e.g. LLLNNNNNN (L is a letter, N is a number). Explain one type of validation that could be used with this field. • Employees are given an annual salary. Explain one type of validation that could be used with this field. -Format check -Length check -range check -data type check
Extension Task • Using the internet, find out how a parity check actually works.