Home > Glossary > Certified Tester Foundation Level > Absence-of-Errors Fallacy

📖 What is Absence-of-Errors Fallacy?

The Absence-of-Errors Fallacy is the incorrect belief that finding and fixing a large number of defects will ensure the success of a system. Even if software is 100% defect-free, it may still fail if it does not meet the users' needs and expectations.

🥋 Sensei Says:

"A perfectly working system is useless if it's not what the customer wanted. Validation (building the right system) is just as important as verification (building the system right)."

📚 Certification: Certified Tester Foundation Level (CTFL-v4.0)

🔑 What are the Key Concepts of Absence-of-Errors Fallacy?

▸ Verification vs Validation
▸ Customer satisfaction
▸ Fitness for use

🎯 How does Absence-of-Errors Fallacy appear on the CTFL-v4.0 Exam?

A project delivers zero-defect software, but the client rejects it because it lacks a key feature.

Questions highlighting that meeting specifications isn't enough if the specs are wrong.

❓ Frequently Asked Questions

Can a system with no known defects still fail?

Yes, it can fail to meet user needs or business requirements, making it unusable.

What does the Absence-of-Errors Fallacy teach us?

It teaches that finding and fixing defects does not guarantee a successful or useful product.

Related Terms from Certified Tester Foundation Level

Branch Coverage Keyword-Driven Testing Static Analysis Tool Branch Testing Boundary Value Analysis (BVA) Entry Criteria

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