ISTQB Updated ISTQB-CTFL Exam Questions and Answers by moses

In an incident report, essential details provide context and facilitate the investigation and resolution of the incident. The missing elements in the given incident report are:

I. Identification or configuration of the application: This detail is crucial as it specifies which version or configuration of the application is affected, helping in reproducing the issue. IV. The actions and/or conditions that came before pressing the button: Understanding the sequence of actions leading to the issue is vital for replicating and diagnosing the problem.

The name of the developer (II) and the recommendation of the developer (III) are not typically included in an incident report as they do not contribute to identifying or resolving the incident. The focus is on the incident's details, reproduction steps, and the system's state rather than on personnel or proposed solutions at this stage. Therefore, option B, which includes both I and IV, is the correct answer.

Statement B contradicts the general principles of testing, because running the same test set more often will not increase the chances of finding new defects, unless there are some changes in the system or environment that affect the test results. Running different test sets with different inputs, outputs or conditions would be more effective in finding new defects. Statements A, C and D are consistent with the general principles of testing. Statement A states that most defects are found in a small subset of a system’s modules, which is true according to the defect clustering principle. Statement C states that testing is better if it starts at the beginning of a project, which is true according to the early testing principle. Statement D states that how testing is done, is based on the situation in a particular project, which is true according to the context-dependent testing principle. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, pages 4-6.

Statements I, IV and V are valid testing principles according to the ISTQB syllabus. Statement I states that exhaustive testing is in general impossible, because it would require testing all possible inputs, outputs and combinations of states, which is usually impractical or impossible. Statement IV states that testing cannot guarantee that a program is correct, because testing can only show the presence of defects, not their absence. Statement V states that defects cluster together in certain areas of the product, which means that some modules or functions are more likely to contain defects than others. Statements II and III are invalid testing principles. Statement II states that exhaustive testing should be executed for code intended to be reused, which contradicts statement I. Statement III states that testing may guarantee that a program is correct, which contradicts statement IV. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, pages 4-5.

Statement coverage is a structural coverage metric that measures the percentage of executable statements in the source code that are executed by a test suite1. Decision coverage is another structural coverage metric that measures the percentage of decision outcomes (such as branches or conditions) in the source code that are executed by a test suite1. Decision coverage is a stronger metric than statement coverage, because it requires that every possible outcome of each decision is tested, while statement coverage only requires that every statement is executed at least once2. Therefore, if a test suite achieves 100% decision coverage, it also implies that it achieves 100% statement coverage, because every statement in every branch or condition must have been executed. However, the converse is not true: 100% statement coverage does not guarantee 100% decision coverage, because some branches or conditions may have multiple outcomes that are not tested by the test suite2. For example, consider the following pseudocode:

if (x > 0) then print(“Positive”) else print(“Non-positive”) end if

A test suite that executes this code with x = 1 and x = -1 will achieve 100% statement coverage, because both print statements are executed. However, it will not achieve 100% decision coverage, because the condition x > 0 has only been tested with two outcomes: true and false. The third possible outcome, x = 0, has not been tested by the test suite. Therefore, the test suite may miss a potential bug or error in the condition or the branch.

The other options, such as stale transition coverage, equivalence class coverage, and boundary value coverage, are not guaranteed to be 100% by achieving 100% decision coverage. Stale transition coverage is a structural coverage metric that measures the percentage of transitions between states in a state machine that are executed by a test suite3. Equivalence class coverage is a functional coverage metric that measures the percentage of equivalence classes (or partitions) of input or output values that are tested by a test suite4. Boundary value coverage is another functional coverage metric that measures the percentage of boundary values (or extreme values) of input or output ranges that are tested by a test suite4. These metrics are independent of decision coverage, because they are based on different aspects of the system under test, such as its behavior, functionality, or specification. Therefore, achieving 100% decision coverage does not imply achieving 100% of any of these metrics, and vice versa. References = ISTQB® Certified Tester Foundation Level Syllabus v4.0, Test Coverage in Software Testing - Guru99, Structural Coverage Metrics - MATLAB & Simulink - MathWorks India, Test Design Coverage in Software Testing - GeeksforGeeks.