Chapter 4 – Test Analysis & Design
Invalid Partition – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
An input or output partition covering values that should be rejected by the test object.
In simple words
A group of bad inputs the system is supposed to reject with an error — the negative-testing partition.
Exam tip
Test invalid partitions one at a time so you know which rejection message is wrong.
Related terms
- Valid PartitionA group of good inputs the system is supposed to accept — the happy-path partition.
- Equivalence PartitioningGroup inputs that the system should treat identically, then pick one value from each group. That way you cover behaviour without testing every possible value.
- Negative TestingDeliberately feeding the system bad or unexpected inputs to prove it fails gracefully instead of crashing.
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