Score Higher on Verified CTFL_Syll2018 | ISTQB Certified Tester Foundation Level (Syllabus 2018) Exam Questions with Answers

The statement that does not describe how testing contributes to higher quality is “The testing of software demonstrates the absence of defects”. This statement is false because testing cannot prove that a software system is defect-free or has a certain level of quality because there might be some untested inputs or outputs that could reveal defects or failures. Testing can only provide information about the quality and risk level of a software system based on the observed behavior and results under certain conditions and assumptions. The other statements describe how testing contributes to higher quality by:

• Performing a review of the requirement specifications before implementing the system can enhance quality: This statement is true because reviewing the requirement specifications can help identify and prevent defects, ambiguities, inconsistencies, or incompleteness in the requirements before they are implemented in the system, which can save time and effort and improve customer satisfaction.
• Properly designed tests that pass reduce the level of risk in a system: This statement is true because passing tests can increase confidence that the system meets its requirements and expectations and provides value to the users and customers. Passing tests can also reduce the probability or impact of failures or defects in the system that could cause harm or loss.
• Software testing identifies defects, which can be used to improve development activities: This statement is true because identifying defects can help analyze and remove their causes and prevent them from recurring in future development activities. Identifying defects can also help improve development processes, methods, standards, tools, techniques, etc., by providing feedback and lessons learned.

You can find more information about how testing contributes to higher quality in [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus], Chapter 1.

Regression testing is a type of testing that is performed after a software system has been changed or modified to verify that the changes have not introduced any new defects or adversely affected the existing functionality of the system. Regression testing can be performed when the software system undergoes different types of changes, such as:

• Corrective changes: Changes that fix defects or errors in the software system
• Adaptive changes: Changes that adapt the software system to new platforms or environments
• Perfective changes: Changes that improve the performance or usability of the software system
• Preventive changes: Changes that avoid potential problems or issues in the software system

In this case, the software system was re-deployed because the backend database was changed from one vendor to another, which is an example of an adaptive change. Therefore, the test manager decided to perform some functional tests on the re-deployed system to ensure that the change did not affect the functionality of the system. This is an example of regression testing.

The other types of testing mentioned in the question are not relevant for this scenario. For example:

• Non-functional testing: This type of testing verifies the non-functional aspects of the software system, such as reliability, performance, security, usability, etc.
• Structural testing: This type of testing verifies the internal structure or implementation of the software system, such as code, architecture, design, etc.
• Unit testing: This type of testing verifies individual components or units of software in isolation from other components or systems.

You can find more information about regression testing in [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus], Chapter 2, Section 2.4.

The term ‘Pesticide paradox’ refers to the phenomenon where the effectiveness of test cases that are repeated and focused on the same scenarios decreases over time because they tend to find the same defects or no defects at all. This is because the system under test becomes more resistant or immune to the existing test cases, just like pests become more resistant or immune to pesticides over time. To overcome the pesticide paradox, test cases should be regularly reviewed and updated to cover new or changed requirements, scenarios, risks, or defects. Test cases should also be designed to cover different aspects and perspectives of the system under test, such as functionality, usability, performance, security, etc. You can find more information about the pesticide paradox in A Study Guide to the ISTQB® Foundation Level 2018 Syllabus, Chapter 4, Section 4.11.