volume_mute

Error Masking in Testing

publish date: 2026/06/14 04:09:33.020347 UTC

volume_mute

A testing team discovers unexpected output in the middle of a long test run. They are unsure whether later anomalies are caused by a new error or are side effects of the first error found. Which inspection advantage does this scenario illustrate?

Inspections check broader quality attributes

Inspections are cheaper per defect found than testing

Inspections can review incomplete systems

During testing, errors can mask other errors, but inspection avoids this problem

Correct Answer

During testing, errors can mask other errors, but inspection avoids this problem

Explanation

This is a classic case of error masking. When an error leads to unexpected outputs during testing, later anomalies may be due to a new error or side effects of the original error - making it hard to separate issues. Because inspection does not involve executing the system, this problem does not arise, and a single inspection session can discover many errors.

Reference

Software Engineering, Ian Sommerville, 10th edition

Quizzes you can take where this question appears

Verification, Validation, and Inspections