CTFL-v4 Fundamentals of Testing Practice Question
A project manager argues that testing is too expensive and suggests skipping the test planning phase to start coding immediately. Which ISTQB principle best counters this argument?
⚠ Common exam trap
Candidates may choose 'Testing is context-dependent' or 'Testing shows the presence of defects', missing the specific link between planning and the cost-reduction benefit of early testing.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Early testing reduces the cost of fixing defects found later in the lifecycle.
Testing is most cost-effective when planned early. The 'early testing' principle states that testing activities should begin as soon as possible. Skipping planning leads to reactive, disorganized testing that misses critical defects, ultimately costing far more to fix after release. By planning, testers prioritize high-risk areas, ensuring that resources are focused on the parts of the system most likely to fail, thereby maximizing the return on investment for testing efforts.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Defect clustering suggests that testing is only needed for one module.
Why it's wrong here
Defect clustering means that a small number of modules often contain the majority of defects. While this helps prioritize testing, it does not justify skipping planning. Planning is necessary to identify which modules are the 'clusters' and how to allocate testing resources efficiently to those specific areas.
- ✓
Early testing reduces the cost of fixing defects found later in the lifecycle.
Why this is correct
The 'early testing' principle highlights that finding bugs during requirements or design is significantly cheaper than finding them during production. Early planning allows for static testing, which identifies issues before a single line of code is written, drastically reducing the overall cost of quality for the entire project.
- ✗
Testing is context-dependent, so planning is unnecessary for small projects.
Why it's wrong here
Context-dependence means testing strategies must adapt to the project, not that planning can be ignored. Even small projects require a strategy to ensure testing aligns with business goals. Skipping planning in small projects often results in missing critical requirements, leading to failure regardless of the project's overall size or scope.
- ✗
Exhaustive testing is impossible, so planning only wastes time.
Why it's wrong here
The impossibility of exhaustive testing is exactly why planning is crucial. Because we cannot test everything, we must plan how to select the most effective tests. Without a plan, testers will randomly choose scenarios, likely missing high-risk areas while over-testing low-risk ones, which is an inefficient use of resources.
Visual reference
About these practice questions
One of 144 original CTFL-v4 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official ISTQB exam blueprint
This CTFL-v4 practice question is part of Courseiva's free ISTQB certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CTFL-v4 exam.