Validation and verification
Any form of interaction with a computer needs to be checked to ensure that what is coming in is what was expected. This could be sign up information on web forms to bar codes. Errorneous infromation can lead to many issues and many bugs in software can be traced back to unexpecting input.
There are two ways to check information coming into a computer
- Validation - Ensure data is in the expected format before during entry
- Verification - Ensure data is correct once it has been entered on the system
When data is being put into a computer ssytem we can perform validation checks. These include
- checksums - used in barcodes and CRC protocol
- Data type check - to ensure things such as "hello" are not put into number fields
- Size check - to ensure that input is between a specified size
- Pressence or null check - to make sure something has been entered
- Range check - To ensure that dates or numbers are between a certain range
When data has been entered we can do verification checks such as -
- Double entry - Force entry twice then compare the inputs
- Proof reading - manually look over the data once inputted