Revise Computingrevisecomputing.co.uk
At a glanceFeaturesStudentsPricingHow it worksFree GCSE notesExam dates
At a glanceFeaturesStudentsPricingHow it worksFree GCSE notesExam dates

Knowledge organisers / Testing

Test data types

All topicsPractise exam questions
Knowledge organiser

Testing

301.13b

Normal, boundary, erroneous.

What you need to know

There are three types of test data: normal (typical valid input), boundary (at the edge of valid ranges), and erroneous (invalid input that should be rejected).

Key points

  • Normal: typical valid data (e.g. age = 25)
  • Boundary: at the limits (e.g. age = 0, age = 120)
  • Erroneous: invalid data (e.g. age = -5, age = "abc")
  • Test all three types for thorough coverage

Code examples

Test data for age 0-120
python
# Normal: 25, 50, 80
# Boundary: 0, 1, 119, 120
# Erroneous: -1, 121, "hello", 3.5