ISTQB Updated ISTQB-CTFL Exam Questions and Answers by andy

This answer is correct because shift-left in testing is an approach that aims to perform testing activities as early as possible in the software development lifecycle, in order to find and fix defects faster and cheaper, and to improve the quality of the software product. Continuous integration is a practice that supports shift-left in testing, as it involves integrating and testing the software components frequently, usually several times a day, using automated tools and processes. Continuous integration can reduce the time between the introduction of a defect and its detection, thereby reducing the cost to fix it and the risk of accumulating defects that could affect the functionality or performance of the software product. References: ISTQB Foundation Level Syllabus v4.0, Section 3.1.1.3, Section 3.2.1.3

Involving testers only during the testing phase is incorrect as per the ISTQB CTFL syllabus. Effective involvement of testers is crucial throughout the entire software development lifecycle (SDLC). This includes early stages such as requirement analysis and design, which allows testers to understand the design decisions and detect defects early. Early involvement helps in better understanding the project and ensures that quality is built into the product from the beginning. Furthermore, the ISTQB syllabus emphasizes the importance of testers contributing to all activities in the SDLC, including design discussions, to enhance defect detection and prevention.

This answer is correct because error guessing is a test design technique where the experience and intuition of the tester are used to anticipate where errors, defects and failures have occurred or are likely to occur, and to design test cases to expose them. Error guessing can be based on factors such as the complexity of the system or component, the known or suspected weaknesses of the system or component, the previous history of defects, or the common types of errors in the domain or technology. Error guessing can be used as a complementary technique to other more systematic or formal techniques, or when there is insufficient information or time to apply them. References: ISTQB Glossary of Testing Terms v4.0, ISTQB Foundation Level Syllabus v4.0, Section 2.3.2.5

The question is about marking the correct sentences among the given statements related to defects, failures, and mistakes. According to the ISTQB glossary, the definitions of these terms are1:

Defect: A flaw in a component or system that can cause the component or system to fail to perform its required function, e.g. an incorrect statement or data definition. A defect, if encountered during execution, may cause a failure of the component or system.

Failure: An event in which a component or system does not perform a required function within specified limits.

Mistake: A human action that produces an incorrect result.

Therefore, out of the five given statements, only two are correct, namely:

A human mistake may produce a defect: This is true, as a mistake is a source or cause of a defect, e.g. a programmer may make a mistake in writing a code statement, which results in a defect in the software component.

When a defect exists in a system it may result in a failure: This is true, as a defect is a potential or actual cause of a failure, e.g. a defect in the software component may cause the system to fail to perform a required function when the defect is encountered during execution.

The other three statements are incorrect, namely:

Defects are a result of environmental conditions and are also referred to as “Failures”: This is false, as defects are not a result of environmental conditions, but of mistakes or other factors, and defects are not the same as failures, but rather the causes of failures.

A system will totally fail to operate correctly when a failure exists in it: This is false, as a system may not necessarily fail completely or stop operating when a failure occurs, but may continue to operate with reduced functionality or performance, or with incorrect results.

Defects occur only as a result of technology changes: This is false, as defects can occur due to various reasons, not only technology changes, such as human mistakes, design flaws, requirement changes, hardware failures, etc.