23L3 - Testing
In this lesson, we focus on testing and test data, which are key ideas in producing robust programs for OCR GCSE Computer Science.
Students learn what testing actually means, why it is a deliberate step in program development, and how programmers use chosen inputs to check that programs behave sensibly before real users start using them.
We then explore the three types of test data required by the OCR specification:
Normal test data – valid, typical values
Boundary test data – valid values at the edge of the allowed range
Erroneous test data – invalid values that should be rejected safely
The lesson explains why all three types are needed together, how boundary values often reveal logical errors, and how testing links directly to robustness by preventing crashes and unpredictable behaviour.
This lesson prepares students for OCR Paper 2, where they are expected to explain test data choices clearly and use correct technical language.
Key terms covered
Testing, test data, normal data, boundary data, erroneous data, robustness, invalid input, edge values
OCR specification links
J277 – 2.3 Producing Robust Programs
Testing and test data (Paper 2 focus)
Next lesson
In the next lesson, we apply these ideas to exam-style scenarios and practise selecting appropriate test data for unseen problems.
Hashtags
#OCRComputerScience #GCSEComputerScience #TestData #RobustPrograms #Programming #Paper2 #ComputerScienceGCSE