- This involves double entry or independent entry by two different operators.
- This ensures that the input data are acceptable (接受) and reasonable (合理) by validation programs. (有效性檢驗程序)
Type of validation check
Presence Check (存在檢查) - used to ensure that all the data items are present
Length Check (長度檢查) - used to ensure the correct number of characters or digits in a data items.
Range Check (範圍檢查) - ensure that the data lie within a certain range.
Type check (類型檢查) - check the type of data is correct
Check digit (檢查數位) - An extra digit is added to ensure the correctness of the codes
Control Total(控制檢查總計) - Ensure that there is no loss of records before data processing in computers.