Validation

Validation is the automated checking by a program that data is reasonable before it is accepted into a computer system. Different types of check may be used on the same piece of data; for example an examination mark could be checked for reasonableness by using a range check, a type check and a presence check. When data is validated by a computer system, if the data is rejected a message should be output explaining why the data was rejected and another opportunity given to enter the data.