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📖 What is Confirmation Bias?

Confirmation bias is the psychological tendency to search for, interpret, favor, and recall information in a way that confirms one's preexisting beliefs or hypotheses. In testing, developers may subconsciously test their code only to show it works, rather than trying to break it.

🥋 Sensei Says:

"This is why independent testing is crucial. A developer's confirmation bias makes it hard for them to find defects in their own work."

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

🔑 What are the Key Concepts of Confirmation Bias?

▸ Independent testing
▸ Psychology of testing
▸ Objective evaluation

🎯 How does Confirmation Bias appear on the CTFL-v4.0 Exam?

Why a developer missed a critical bug in their own code.

Questions about the value of independent test teams.

❓ Frequently Asked Questions

Why is independent testing recommended?

It helps overcome confirmation bias, as an independent tester is less likely to subconsciously prove the software works.

Can developers test their own code?

Yes, typically through component testing, but they must be aware of their own confirmation bias.

Related Terms from Certified Tester Foundation Level

Action (Decision Table) Data-Driven Testing Checklist-based Review Branch Coverage Test Monitoring Test Management Tool

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