CTFL-v4 Fundamentals of Testing Practice Question
What is the primary reason for performing 'regression testing' throughout the software development lifecycle?
⚠ Common exam trap
Exam takers often confuse regression testing with confirmation testing, incorrectly thinking regression checks if a specific fixed bug is gone rather than ensuring existing features still work.
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
✓
To ensure that changes have not adversely affected existing system features.
Regression testing is vital because changes to software, such as bug fixes or feature additions, often introduce unintended side effects in previously working parts of the system. By re-executing tests, teams ensure that existing functionality remains intact. This practice is essential for maintaining software stability and confidence in the system, preventing the degradation of quality as the product evolves over time and becomes more complex.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
To verify that new requirements are correctly implemented by the developers.
Why it's wrong here
Verifying new requirements is known as confirmation testing or functional testing, not regression testing. Regression testing focuses on existing functionality. While it is important to test new features, confusing these terms leads to ineffective test planning and failure to detect regressions in the existing, stable system components.
- ✓
To ensure that changes have not adversely affected existing system features.
Why this is correct
Regression testing specifically aims to identify defects introduced by changes. As code is modified, the risk of breaking existing features increases. Executing regression suites ensures that current stability is maintained, which is critical for preventing new code from causing regressions in previously stable and verified parts of the application.
- ✗
To improve the performance of the system under high user load.
Why it's wrong here
Regression testing is designed to verify functional correctness after changes, not to optimize performance. Performance testing is a distinct activity involving load, stress, and scalability analysis. conflating these two activities prevents the team from properly addressing performance bottlenecks, which require specialized tools and methodologies unrelated to functional regression suites.
- ✗
To replace the need for unit testing on modified modules.
Why it's wrong here
Regression testing does not replace unit testing. Unit tests provide fast feedback on low-level changes. Regression testing is often broader, potentially covering integration and system levels. Relying solely on regression testing for changed modules would delay feedback and increase the effort required to identify the root cause of failures.
About these practice questions
Courseiva writes every CTFL-v4 question from scratch — 144 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. 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.