Test Oracle
A test oracle is a source used to determine the expected result of a test and decide whether the actual result is correct.
“A source to determine an expected result to compare with the actual result of the system under test.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Test Oracle?
Test oracles may include specifications, requirements, calculations, models, or expert knowledge that define correct system behavior.
Expected outcome source: Determines pass or fail.
Can take many forms: Documentation, models, or experts.
Essential for verification: Enables objective evaluation.
Real World Example
A regulated product team is preparing a release where Test oracle appears in reviews, test design conversations, or defect triage rather than as an isolated glossary word.
The risk is that the team treats Test oracle as interchangeable with nearby ISTQB terms. That makes test scope blurry and can lead to weak evidence for the release decision.
The tester anchors the discussion in the official definition, asks where the concept appears in the product, and designs examples that show the difference between Test oracle and similar ideas.
The page becomes useful in practice because Test oracle is connected to a specific testing decision, not memorized as a detached definition.
Practice Questions
Question 1
Which statement BEST describes Test oracle in the context of ISTQB terminology?
Question 2
A tester needs to explain Test oracle to a non‑technical stakeholder. Which approach is MOST appropriate?
Test your knowledge with real ISTQB-style questions
You’ve learned Test Oracle. Test your understanding with topic-specific questions in our Mock Exams.