Advanced – Non-Functional Testing
Functional Correctness – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
The degree to which a product provides the correct results with the needed degree of precision.
In simple words
Does the function produce the right output for the given input?
Exam tip
Sub-characteristic of Functional Suitability in ISO 25010.
Related terms
- Functional SuitabilityDoes the software actually do what it should? Correctness, completeness, appropriateness.
- ISO/IEC 25010The reference model with 8 product quality characteristics and 5 quality-in-use characteristics.
- Functional TestingDoes the feature do what the spec says? Login logs you in, checkout charges the right amount.
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