ISTQB Certified Tester Foundation Level (CTFL 2018) — Question 30

Which of the following options BEST explains the pesticide paradox principle of testing?

Answer options

• A. If we do not regularly review and revise our tests, we'll stop finding defects.
• B. Repeatedly running a set of tests will ensure that a system is defect free.
• C. Defects are, paradoxically, often contained in a small number of modules.
• D. Testing, like spraying pesticide, is an effective bug/defect removal activity.

Correct answer: A

Explanation

The correct answer is A because it highlights the necessity of regularly reviewing tests to discover defects. Option B is incorrect since running the same tests repeatedly does not guarantee defect-free software. Option C misrepresents the concept by suggesting defects are only in a few modules, while D inaccurately equates testing to pesticide application without emphasizing the need for continual test updates.