Validation, Verification and Testing

What Validation, Verification and Testing covers

Validation, Verification and Testing is examined mainly in Component 1, Programming and System Development, with its subtopic on validating and verifying data in databases belonging to Component 2, Computer Architecture, Data, Communication and Applications. It covers validation and verification compared, types of validation check, implementing validation in an algorithm, verification techniques, validation and verification of data in databases, choosing test data and dry running, trace tables and identifying errors.

The 7 subtopics

Each one has its own page.

• Validation and verification comparedData validation, data verification and why validation cannot guarantee that data is accurate.Open →
• Types of validation checkRange check and a limit check and purpose of a check digit.Open →
• Implementing validation in an algorithmBenefit of writing a validation check as a separate function, defensive programming and how a drop-down list reduces the need for validation code.Open →
• Verification techniquesDouble entry verification, visual verification and one limitation of a single parity bit.Open →
• Validation and verification of data in databasesInput mask, purpose of a required property on a database field and referential integrity acting as a validation check.Open →
• Choosing test dataNormal test data, boundary test data and erroneous test data.Open →
• Dry running, trace tables and identifying errorsDry running an algorithm, trace table and logical error.Open →

What you need to know

Answer each one before you reveal it.

Take Validation, Verification and Testing further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Validation vs Verification

  Validation: asking whether the value is reasonable. Verification: asking whether it was copied correctly.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What is meant by data validation?

   Model answer

   Validation is an automatic check that data entered is sensible and of the expected form. A validation check cannot prove that the data is actually correct.

2. 2

   What is meant by data verification?

   Model answer

   Verification is a check that data has been copied or transferred accurately from its source. The value itself may still be wrong on the original document.

3. 3

   Explain why validation cannot guarantee that data is accurate.

   Model answer

   Validation only tests whether a value obeys a rule such as lying inside a range. A wrong date of birth inside the allowed range passes every check.

4. 4

   A user types a surname into a field that expects a date. Which kind of check rejects the entry?

   Model answer

   A type check rejects the entry because letters are not a valid date value. The rejection happens before the data is written to the file.

5. 5

   Give one situation where verification matters more than validation.

   Model answer

   Verification matters most when data is re-keyed from paper forms into a computer system. A typing slip produces a plausible value that passes every validation rule.

6. 6

   Why are validation and verification normally used together?

   Model answer

   Validation traps values of the wrong form and verification traps values copied wrongly. Neither check on its own removes both classes of error.

What is inside Levo

Six ways to work the same material.

Validation, Verification and Testing revision questions

What does Validation, Verification and Testing cover in Eduqas A-Level Computer Science?

7 subtopics: validation and verification compared, types of validation check, implementing validation in an algorithm, verification techniques, validation and verification of data in databases, choosing test data and dry running, trace tables and identifying errors. Each one has its own page with questions and model answers.

How is Validation, Verification and Testing organised?

By the Eduqas A500QS specification, subtopic by subtopic, so it matches the order you are taught it in.