Anomaly
An anomaly is any observed condition that differs from what is expected, regardless of whether the cause has been identified.
“A condition that deviates from expectation.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Anomaly?
Anomalies include unexpected behaviors, inconsistent results, documentation issues, or unusual observations discovered during testing or reviews. They may or may not indicate actual defects.
Broad concept: Not every anomaly is confirmed as a software defect.
Discovery: Anomalies can be found during both static and dynamic testing.
Investigation: Additional analysis determines whether an anomaly represents a real problem.
Real World Example
A hospital medication system shows a different dosage warning in test than the one specified by the clinical safety rule.
The team needs precise language to separate what was observed, what should have happened, and whether the difference represents a reportable issue. Anomaly provides that distinction.
The tester records the steps, data, observed behavior, expected behavior, and evidence so triage can focus on patient safety impact instead of vague descriptions.
The issue is handled faster because Anomaly helps everyone discuss the problem using a shared testing vocabulary.
Practice Questions
Question 1
During testing, a report totals to 9,998 instead of the expected 10,000. What is the BEST next step regarding the anomaly?
Question 2
Which description BEST fits ‘anomaly’ in a test execution log?
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