False Negative

 A false negative in software testing occurs when a test fails to detect a defect or issue in the software, meaning the test result shows that everything is fine when there actually is a problem. This means a real issue goes unnoticed.

Example:

Imagine you have a test that checks if a login feature works correctly. The test is supposed to verify that users cannot log in with invalid credentials. If the test passes and reports that the login feature is secure, but in reality, users can log in with invalid credentials, this is a false negative.

Causes:

• Insufficient Test Coverage: The test might not cover all possible scenarios or edge cases, allowing some defects to slip through.
• Test Script Errors: The test script might have flaws or omissions that prevent it from detecting certain issues.
• Data Issues: Using incorrect or incomplete test data might lead to missed defects.
• Configuration Problems: Incorrect configurations in the test environment can cause some issues to remain undetected.

Impact:

• Undetected Defects: Defects that go unnoticed can make it to production, potentially leading to software failures or user dissatisfaction.
• False Sense of Security: Believing that the software is defect-free when it is not can lead to a lack of preparedness for potential issues.
• Increased Costs: Undetected defects can be more costly to fix later, especially if they cause significant problems in production.

Mitigation:

• Comprehensive Testing: Ensure test cases cover a wide range of scenarios, including edge cases.
• Review and Update Tests: Regularly review and update test scripts to improve their accuracy and coverage.
• Robust Test Data: Use diverse and representative test data to uncover more defects.
• Configuration Management: Maintain consistent and correct test environments to avoid configuration-related issues.

Summary:

A false negative is a test result that fails to identify a real defect in the software. It gives a misleading assurance that everything is working correctly, which can lead to undetected issues making it into production and causing problems later on.