CTFL_Syll2018 Exam Dumps : ISTQB Certified Tester Foundation Level (Syllabus 2018)

The application failed because of a defect in the purchase identification module caused by a programmer mistake or an error in the specification. A defect is a flaw or imperfection in a software product that causes it to fail to meet its requirements or expectations. A failure is an event or behavior of a software product that deviates from its requirements or expectations. An error is a human action or decision that produces a defect. A mistake is an incorrect action or decision that leads to an error. In this case, the application failed because it incorrectly counted purchase attempts, which was a defect in the purchase identification module. The defect was caused by either a programmer mistake (such as writing wrong code) or an error in the specification (such as defining wrong requirements). A detailed explanation of defects, failures, errors, and mistakes can be found in [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus], pages 5-6.

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.

Work Breakdown Structure (WBS) is a project management technique that decomposes a project into smaller and manageable tasks. It is not a factor that is used as a basis for estimating testing effort, but rather an outcome of the estimation process. The other options are factors that can influence the testing effort, such as the quality of the test basis, the requirements for documentation, and the skills of the test team.

References: Section 2.3, Section 2.4