Validation techniques

Question 1

How is validation different to testing?

Answer 1

Validation checks that input data are reasonable. Validation cannot check that inputs are accurate.

Question 2

Create a table listing what validation does and does not do.

Answer 2

Validation can check:
Existence
Data type
Range checks
Format
Consistency
Reasonableness

Validation cannot check:
Accuracy
Whether the number is correct
If the calculation is working
Wrong data

Question 3

List three types of validation.

Answer 3

1. Existence checks ensure that a value has been entered and the field is not blank, or <null>.</null>
2. Type checks ensure data is of the right type.
3. Range checks ensure that data is within acceptable limits or comes from a list of acceptable values.
4. Format checks ensure that data is in the correct format.
5. Consistency checks perform a comparison between different entries .
   e.g. via use of surveys
6. Reasonableness checks consider whether the inputs are plausible.