Data validation and verification

Overview

Data validation, data verification and range check.

What you need to know

Answer each one before you reveal it.

Questions from this subtopic

Each one with the model answer underneath.

1. 1

   What is data validation?

   Model answer

   Validation is a check carried out by the program that the data supplied is reasonable and of the right form before it is accepted.

2. 2

   What is data verification?

   Model answer

   Verification is a check that the data entered matches the source it was copied from.

3. 3

   Why can validation never guarantee that data is correct?

   Model answer

   It can only test whether a value is plausible, so a wrong value that happens to be plausible, such as a valid date of birth belonging to somebody else, passes every check.

4. 4

   Describe a range check.

   Model answer

   A range check tests that a numeric or date value falls between a stated lowest and highest permitted value, such as a month lying between 1 and 12.

5. 5

   Describe a presence check.

   Model answer

   A presence check tests that a field which must be completed has not been left empty.

6. 6

   Describe a format check.

   Model answer

   A format check tests that the value follows a required pattern of characters, such as two letters followed by two digits for a code.

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