ISTQB-CTFL ISTQB Certified Tester Foundation Level (CTFL) v4.0 Questions and Answers

The test pyramid concept suggests that there should be more low-level tests (unit tests) and fewer high-level tests (end-to-end tests).

As we move higher up the pyramid (e.g., from unit tests to integration tests to end-to-end tests), each test covers more production code.

Higher-level tests (like end-to-end) validate larger parts of the application, including multiple units and their interactions.

This aligns with the principle that higher-level tests provide broader coverage but are fewer in number and more expensive to run and maintain.

Good traceability between the test basis and test work products provides several advantages: i. Analyzing the impact of changes: Traceability allows for easy identification of which parts of the test work products will be affected by changes in the requirements or design, facilitating impact analysis. iv. Making testing auditable: Traceability ensures that there is a clear connection between the requirements and the test cases, which makes the testing process auditable and provides evidence that all requirements have been tested​​.

 The thought process of the software company is incorrect, because it assumes that each artifact can be reviewed using only one review method, and that the review method depends solely on the criticality of the artifact. This is a simplistic and rigid approach that does not consider the benefits and limitations of different review methods, the context and purpose of the review, and the feedback and improvement opportunities that can be gained from multiple reviews. According to the CTFL 4.0 Syllabus, the selection of review methods should be based on several factors, such as the type and level of detail of the artifact, the availability and competence of the reviewers, the time and budget constraints, the expected defects and risks, and the desired outcomes and quality criteria. Moreover, the same artifact can be reviewed using different review methods at different stages of the development lifecycle, to ensure that the artifact meets the changing requirements, standards, and expectations of the stakeholders. For example, a requirement specification can be reviewed using an informal review method, such as a walkthrough, to get an initial feedback from the users and developers, and then using a formal review method, such as an inspection, to verify the completeness, correctness, and consistency of the specification. Therefore, the software company should adopt a more flexible and context-sensitive approach to selecting and applying review methods for different artifacts, rather than following a fixed and arbitrary rule. References = CTFL 4.0 Syllabus, Section 3.2.1, page 31-32; Section 3.2.2, page 33-34; Section 3.2.3, page 35-36.

In Agile teams, close collaboration among testers and other team members can lead to organizational risks such as: ii. Close interaction with developers causes a loss of the appropriate tester mindset. iv. Testers, once they have acquired technical development or business skills, leave the testing team.

These risks highlight the potential issues of diminished testing perspective and team turnover when testers integrate closely with developers and other roles​​.

The ISTQB CTFL syllabus identifies several causes for defects in software. One prominent reason, as highlighted in the curriculum, is the pressure and rush to meet tight deadlines, which can lead to insufficiently reviewed or tested code being moved into further stages of testing or production. This scenario describes rushing to meet a deadline as a potential cause for defects because it may compromise the thoroughness of code development and testing.References:ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 1.4.1 "Why is Testing Necessary?".

The statement that refers to good testing practice to be applied regardless of the chosen software development model is option D, which says that involvement of testers in work product reviews should occur as early as possible to take advantage of the early testing principle. Work product reviews are static testing techniques, in which the work products of the software development process, such as the requirements, the design, the code, the test cases, etc., are examined by one or more reviewers, with or without the author, to identify defects, violations, or improvements. Involvement of testers in work product reviews can provide various benefits for the testing process, such as improving the test quality, the test efficiency, and the test communication. The early testing principle states that testing activities should start as early as possible in the software development lifecycle, and should be performed iteratively and continuously throughout the lifecycle. Applying the early testing principle can help to prevent, detect, and remove defects at an early stage, when they are easier, cheaper, and faster to fix, as well as to reduce the risk, the cost, and the time of the testing process. The other options are not good testing practices to be applied regardless of the chosen software development model, but rather specific testing practices that may or may not be applicable or beneficial for testing, depending on the context and the objectives of the testing activities, such as:

Tests should be written in executable format before the code is written and should act as executable specifications that drive coding: This is a specific testing practice that is associated with test-driven development, which is an approach to software development and testing, in which the developers write automated unit tests before writing the source code, and then refactor the code until the tests pass. Test-driven development can help to improve the quality, the design, and the maintainability of the code, as well as to provide fast feedback and guidance for the developers. However, test-driven development is not a good testing practice to be applied regardless of the chosen software development model, as it may not be feasible, suitable, or effective for testing in some contexts or situations, such as when the requirements are unclear, unstable, or complex, when the test automation tools or skills are not available or adequate, when the testing objectives or levels are not aligned with the unit testing, etc.

Test levels should be defined such that the exit criteria of one level are part of the entry criteria for the next level: This is a specific testing practice that is associated with sequential software development models, such as the waterfall model, the V-model, or the W-model, in which the software development and testing activities are performed in a linear and sequential order, with well-defined phases, deliverables, and dependencies. Test levels are the stages of testing that correspond to the levels of integration of the software system, such as component testing, integration testing, system testing, and acceptance testing. Test levels should have clear and measurable entry criteria and exit criteria, which are the conditions that must be met before starting or finishing a test level. In sequential software development models, the exit criteria of one test level are usually part of the entry criteria for the next test level, to ensure that the software system is ready and stable for the next level of testing. However, this is not a good testing practice to be applied regardless of the chosen software development model, as it may not be relevant, flexible, or efficient for testing in some contexts or situations, such as when the software development and testing activities are performed in an iterative and incremental order, with frequent changes, feedback, and adaptations, as in agile software development models, such as Scrum, Kanban, or XP, when the test levels are not clearly defined or distinguished, or when the test levels are performed in parallel or concurrently, etc.

Test objectives should be the same for all test levels, although the number of tests designed at various levels can vary significantly: This is a specific testing practice that is associated with uniform software development models, such as the spiral model, the incremental model, or the prototyping model, in which the software development and testing activities are performed in a cyclical and repetitive manner, with similar phases, deliverables, and processes. Test objectives are the goals or the purposes of testing, which can vary depending on the test level, the test type, the test technique, the test environment, the test stakeholder, etc. Test objectives can be defined in terms of the test basis, the test coverage, the test quality, the test risk, the test cost, the test time, etc. Test objectives should be specific, measurable, achievable, relevant, and time-bound, and they should be aligned with the project objectives and the quality characteristics. In uniform software development models, the test objectives may be the same for all test levels, as the testing process is repeated for each cycle or iteration, with similar focus, scope, and perspective of testing. However, this is not a good testing practice to be applied regardless of the chosen software development model, as it may not be appropriate, realistic, or effective for testing in some contexts or situations, such as when the software development and testing activities are performed in a hierarchical and modular manner, with different phases, deliverables, and dependencies, as in sequential software development models, such as the waterfall model, the V-model, or the W-model, when the test objectives vary according to the test levels, such as component testing, integration testing, system testing, and acceptance testing, or when the test objectives change according to the feedback, the learning, or the adaptation of the testing process, as in agile software development models, such as Scrum, Kanban, or XP, etc. References: ISTQB Certified Tester Foundation Level (CTFL) v4.0 sources and documents:

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 1.1.1, Testing and the Software Development Lifecycle1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 1.2.1, Testing Principles1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 1.2.2, Testing Policies, Strategies, and Test Approaches1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 1.3.1, Testing in Software Development Lifecycles1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.1, Test Planning1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.2, Test Monitoring and Control1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.3, Test Analysis and Design1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.4, Test Implementation1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.5, Test Execution1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.6, Test Closure1

ISTQB® Glossary of Testing Terms v4.0, Work Product Review, Static Testing, Early Testing, Test-driven Development, Test Level, Entry Criterion, Exit Criterion, Test Objective, Test Basis, Test Coverage, Test Quality, Test Risk, Test Cost, Test Time2

Option D correctly explains what is represented by the lines A, B and the axes X, Y in a testing metrics chart. According to option D:

X-axis represents Time

Y-axis represents Count

Line A represents Number of open bugs

Line B represents Total number of executed tests

This information is essential in understanding and analyzing the testing metrics of a completed project.

References: ISTQB Certified Tester Foundation Level (CTFL) v4.0 Syllabus, Section 2.5.1, Page 35.

Exercising at least one of the decision outcomes for all decisions within the code, ensures achieving full branch coverage, which is a test coverage criterion that requires that all branches in the control flow of the code are executed at least once by the test cases. A branch is a basic block of code that has a single entry point and a single exit point, and a decision is a point in the code where the control flow can take more than one direction, such as an if-then-else statement, a switch-case statement, a loop statement, etc. The decision outcomes are the possible paths that can be taken from a decision, such as the then branch or the else branch, the case branch or the default branch, the loop body or the loop exit, etc. The other statements are false, because:

The minimum number of test cases needed to achieve full branch coverage, is usually higher than that needed to achieve full statement coverage, which is a test coverage criterion that requires that all executable statements in the code are executed at least once by the test cases. This is because branch coverage is a stronger criterion than statement coverage, as it implies statement coverage, but not vice versa. For example, a single test case can achieve full statement coverage for an if-then-else statement, but two test cases are needed to achieve full branch coverage, as both the then branch and the else branch need to be exercised.

If full branch coverage has been achieved, then all unconditional branches within the code have not necessarily been exercised, as unconditional branches are branches that do not depend on any decision, and are always executed, such as a goto statement, a break statement, a return statement, etc. Unconditional branches are not part of the branch coverage criterion, as they do not represent different paths in the control flow of the code. However, they are part of the statement coverage criterion, as they are executable statements in the code.

If full branch coverage has been achieved, then all combinations of conditions in a decision table have not necessarily been exercised, as a decision table is a test design technique that represents the logical relationships between multiple conditions and their corresponding actions, in a tabular format. A decision table can have more combinations of conditions than the number of decision outcomes in the code, as each condition can have two or more possible values, such as true or false, yes or no, etc. For example, a decision table with four conditions can have 16 combinations of conditions, but the corresponding code may have only two decision outcomes, such as pass or fail. To exercise all combinations of conditions in a decision table, a stronger test coverage criterion is needed, such as condition combination coverage, which requires that all possible combinations of condition outcomes in the code are executed at least once by the test cases. References: ISTQB Certified Tester Foundation Level (CTFL) v4.0 sources and documents:

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.3.1, Test Coverage Criteria Based on the Structure of the Software

ISTQB® Glossary of Testing Terms v4.0, Branch Coverage, Statement Coverage, Branch, Decision, Decision Outcome, Unconditional Branch, Decision Table, Condition Combination Coverage

The correct test execution sequence should consider both the dependencies between the requirements and their priorities. According to the diagram, the sequence begins with R2 (P1) as it is a prerequisite for R3 (P4). Then R1 (P3) can be tested. R3 follows as it depends on R2. Next, R7 (P4) should be tested before R6 (P3) and R5 (P2), as indicated by their dependencies. Finally, R4 (P1) and R8 (P1) can be tested. Therefore, the best sequence is R2, R1, R3, R7, R6, R5, R4, R8. Reference: ISTQB CTFL Syllabus V4.0, Section 5.1.5

When working on a project with incomplete requirements and under pressure to deploy, exploratory testing is particularly suitable. This type of testing allows testers to use their expertise and intuition to explore the system's functionality and identify defects without needing detailed specifications. Exploratory testing is flexible and can quickly adapt to changes and gaps in the requirements​​.

Behavior-Driven Development (BDD) is a collaborative approach that enhances communication among project stakeholders, including developers, testers, and business analysts. It involves defining how software should behave through examples written in a common language understandable by all stakeholders, often using the Given-When-Then format​​.

Confirmation testing, also known as re-testing, is performed to verify that specific defects have been successfully fixed.

Option A: "Testing due to the application of a new version of the interface" would typically involve regression testing, not confirmation testing.

Option B: "Testing that fixes resolved the defects in the search function" fits the description of confirmation testing as it focuses on ensuring that specific issues have been addressed.

Option C: "Testing if a system still works after update of an operating system" is an example of regression testing, as it checks the overall system behavior after an update.

Option D: "Testing to ensure the adding of new functionalities haven't broken existing functions" is another example of re​ (ISTQB not-for-profit association)​​ (Udemy)​ it checks for unintended consequences of new changes.

Therefore, the correct answer is B【6†source】【9†source】.

References:

Certified Tester Foundation Level v4.0

ISTQB Foundation Level Syllabus 4.0 (2023)

The benefits of continuous integration include: i. Allows earlier detection and easier root cause analysis of integration problems and conflicting changes. iv. Gives the development team regular feedback on whether the code is working. These benefits help in maintaining the stability and quality of the codebase by integrating and testing changes frequently and providing quick feedback to developers​​.

A pilot project is a small-scale experiment or trial that is conducted to evaluate the feasibility, effectiveness, and suitability of a test automation tool before implementing it on a larger scale1.

The objectives of a pilot project may vary depending on the context and scope of the test automation initiative, but some common ones are2:

To get familiar with the functionality and options of the tool

To check how the tool fits to the existing test processes and environment

To assess the benefits and challenges of using the tool

To decide upon standards and guidelines for tool implementation and usage

To estimate the costs and resources required for tool deployment and maintenance

Therefore, option C is not a valid objective of a pilot project, as it is not necessary to train all testers on using the tool at this stage. Training all testers on using the tool would be more appropriate after the tool has been selected and approved for full-scale implementation, and after the standards and guidelines have been established. Training all testers on using the tool during the pilot project would be inefficient, costly, and premature, as the tool may not be suitable or effective for the intended purpose, or may be replaced by another tool later.

References:

1: ISTQB Certified Tester Foundation Level Syllabus 2018, Version 4.0, p. 82

2: ISTQB Certified Tester Foundation Level Syllabus 2018, Version 4.0, p. 83

: ISTQB Certified Tester Foundation Level Syllabus 2018, Version 4.0, p. 84

: ISTQB Certified Tester Foundation Level Syllabus 2018, Version 4.0, p. 85

Achieving full code coverage does not guarantee that the component or system is fully tested or free of defects. Code coverage metrics indicate the extent to which the source code has been tested, but they do not account for the quality of the tests or whether all possible scenarios have been considered. Other types of testing, including functional, performance, and security testing, are necessary to ensure comprehensive testing. The ISTQB CTFL Syllabus v4.0 highlights that while high code coverage is beneficial, it does not equate to complete testing​​.

Confirmation testing is performed after a defect is fixed, and if such testing is successful then the regression tests that are relevant for such fix can be executed. Confirmation testing, also known as re-testing, is the process of verifying that a defect has been resolved by running the test case that originally detected the defect. Confirmation testing is usually done before regression testing, which is the process of verifying that no new defects have been introduced in the software as a result of changes or fixes. Therefore, option D is the correct answer.

References: ISTQB® Certified Tester Foundation Level Syllabus v4.01, Section 2.4.1, page 28; ISTQB® Glossary v4.02, page 15.

Statement coverage measures the percentage of executable statements that have been exercised by a test suite. Achieving 80% statement coverage means that 80% of the executable code lines have been tested. This metric helps in understanding how much of the code has been covered during testing. However, it does not guarantee branch coverage, variable initialization, or detection of all possible defects. The ISTQB CTFL Syllabus v4.0 explains statement coverage as a measure of the extent to which the code has been tested, without implying other types of coverage or testing goals​​.

An inspection is a type of review that follows a defined process with formal entry and exit criteria and roles and responsibilities for participants. An inspection can be performed by peers with different roles, such as moderator, author, reviewer and scribe. The following statement about inspection is not true:

B) The main purpose of an inspection is to find solutions to the problems. This statement is not true, as the main purpose of an inspection is to find defects or issues in a work product, not to find solutions to the problems. Finding solutions to the problems is a debugging or problem-solving activity that is usually performed by the author or developer after receiving the inspection report. The following statements about inspection are true:

A) An inspection may be led by a trained moderator who shall not be the author. This statement is true, as an inspection requires a moderator role who leads the inspection process and ensures that it follows the rules and standards. The moderator should be trained in inspection techniques and should not be the author of the work product under inspection, in order to avoid bias or conflict of interest.

C) An inspection can be performed by peers. This statement is true, as an inspection involves peer review, which means that the work product under inspection is evaluated by people who have similar roles or expertise as the author, but who are not directly involved in creating or modifying the work product.

D) An inspection shall follow a formal process based on rules and checklists with entry and exit criteria. This statement is true, as an inspection follows a formal process that consists of six main steps: planning, kick-off meeting, individual preparation, review meeting, rework and follow-up. Each step has defined rules and checklists to guide the participants and ensure consistency and quality. Each step also has entry and exit criteria to ensure that the prerequisites and objectives are met before moving to the next step. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, Chapter 3, page 28-29.

Technical reviews are structured meetings that aim to examine various aspects of a product or project to identify any defects or improvements. Options A (Pre-meeting preparation by reviewers), B (Using checklists during the meeting), and D (Preparation of a review report) are typical activities in a technical review process. Inviting end-users to the meeting (C), however, is generally not part of a typical technical review, as these reviews are usually more focused on the technical aspects and are conducted by peers or experts within the development or testing teams rather than end-users​​.

A failure is an event in which a component or system does not perform a required function within specified limits. A failure is observable by the software users or other stakeholders. A failure is caused by one or more defects in the software. In this case, the software not being able to meet the desired response time is an example of a failure, as it deviates from the stated requirement and affects the user experience. It is not a defect, which is a flaw in the software that causes the failure. It is not an error, which is a human action that produces an incorrect result. It is not a non-defect, as it clearly violates a specified requirement. Verified References: [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer], Chapter 1, page 4.

This answer is correct because static testing and dynamic testing are both types of testing that can be used to highlight issues associated with non-functional characteristics, such as usability, performance, security, reliability, etc. Static testing is a type of testing that involves the analysis of software work products, such as requirements, design, code, or test cases, without executing them. Dynamic testing is a type of testing that involves the execution of software work products, such as code or test cases, using inputs and verifying outputs. Both static testing and dynamic testing can be applied to different test levels and test types, and can use different test techniques and tools, to evaluate the non-functional characteristics of the software product. References: ISTQB Glossary of Testing Terms v4.0, ISTQB Foundation Level Syllabus v4.0, Section 2.2.1.1, Section 2.2.1.2

The fact that defects are usually not evenly distributed among the various modules that make up a software application, but rather their distribution tend to reflect the Pareto principle, is expressed by the testing principle referred to as ‘Defects cluster together’. This principle states that a small number of modules contain most of the defects detected, or that a small number of causes are responsible for most of the defects. This principle can be used to guide the test analysis and design activities, by prioritizing the testing of the most critical or risky modules, or by applying more rigorous test techniques to them. Therefore, option C is the correct answer.

References: ISTQB® Certified Tester Foundation Level Syllabus v4.01, Section 1.2.1, page 11; ISTQB® Glossary v4.02, page 16.

For executive-level employees, a test summary report should be concise and focus on high-level information. It typically includes a summary of defects categorized by priority or budget. Executives are generally interested in the overall status and the impact on critical business objectives rather than detailed technical information. The report should provide an overview of the most important aspects of testing, such as key issues, test progress, and any risks or concerns that could affect project outcomes.References:

ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 5.3.1.

A dynamic analysis tool is a tool that performs analysis of a software product based on its behavior during execution. A dynamic analysis tool can monitor various aspects of a program’s run-time performance, such as memory usage, CPU load, response time, or resource leaks. A dynamic analysis tool can monitor the allocation, use and de-allocation of memory during run-time of a program, which can help detect defects such as memory leaks, buffer overflows, or memory corruption. A dynamic analysis tool cannot provide support for traceability of tests, test results and incidents to source documents, as this is a function of a test management tool. A dynamic analysis tool cannot execute programs step-by-step in order to reproduce failures and find corresponding defects, as this is a function of a debugging tool. A dynamic analysis tool cannot provide support for release of baselines consisting of configuration items, as this is a function of a configuration management tool. Verified References: [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer], Chapter 6, page 56-57.

 Static testing is a form of testing that does not involve executing the software or system under test. It includes activities such as reviews, inspections, walkthroughs, and analysis of documents, code, and models. Static testing can find defects early in the development process, before they become more expensive and difficult to fix in later stages. Static testing can also improve the quality of the software or system by preventing defects from being introduced in the first place. Static testing can complement dynamic testing, which involves executing the software or system under test and checking the results against expected outcomes. Dynamic testing can find defects that static testing may miss, such as performance, usability, or integration issues. However, dynamic testing alone is not sufficient to ensure quality, as it may not cover all possible scenarios, inputs, or paths. Therefore, a test manager who decides to skip static testing is making a wrong decision, as he or she is ignoring the benefits of static testing and relying solely on dynamic testing, which may not be effective or efficient enough to find and prevent defects. References = ISTQB Certified Tester Foundation Level Syllabus, Version 4.0, 2018, Section 2.1.1, page 14; ISTQB Glossary of Testing Terms, Version 4.0, 2018, page 36; ISTQB CTFL 4.0 - Sample Exam - Answers, Version 1.1, 2023, Question 3, page 9.

A test tool used for the analysis of a developer's code prior to its execution falls under the category of static testing tools. Static testing involves examining the code and documentation without executing the code. These tools are used to perform static analysis, which helps in identifying potential defects and code quality issues early in the development process. The ISTQB CTFL syllabus specifies that static analysis tools are essential for finding defects that do not manifest themselves during the execution of the program.

References: ISTQB CTFL Syllabus, Section 3.1, "Static Testing."

Checklist-based testing involves using checklists that contain items, such as potential test conditions, that should be tested. These checklists are often based on insights into what is important to the user, potential areas where software might fail, and specific aspects that need to be tested. It provides a structured yet flexible approach to testing, ensuring key areas are covered while allowing testers to use their experience and understanding of the system. Checklist-based testing is not limited to non-functional testing but can be applied to various types of testing, including functional testing.References:

ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 4.4.5.

Test planning is a key activity in the testing process that involves defining the objectives, approach, resources, and schedule of intended test activities. Setting the entry and exit criteria (I) and determining the number of resources required (III) are integral parts of test planning. Determining the validity of bug reports (II) is more aligned with test analysis or test management activities post-execution, and determining the expected result for test cases (IV) is part of test design. Therefore, options I and III (B) are the activities that belong to test planning​​.

The choice of a software development lifecycle (SDLC) model is primarily influenced by the type of product being developed. Different products and project requirements may demand different SDLC models to address specific challenges and needs efficiently. For instance, a complex, safety-critical product might best be served by a Waterfall model due to its structured nature and phase dependencies, while a more iterative and incremental model might be suited for projects requiring frequent feedback and changes.References:ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 2.1 "Software Development Lifecycles".

The key difference between the mindsets for test activities and development activities lies in the objectives: a tester is primarily concerned with finding defects to ensure product quality, while a developer focuses on designing and building solutions. This distinct focus helps ensure thorough quality checks and balances within the software development life cycle​ (ISTQB not-for-profit association)​.References:

ISTQB® Certified Tester Foundation Level Syllabus v4.0: https://istqb-main-web-prod.s3.amazonaws.com/media/documents/ISTQB_CTFL_Syllabus-v4.0.pdf

Effort estimate does not depend on the budget of the project, but rather on the scope, complexity, and quality of the software product and the testing activities1. Budget is a constraint that may affect the feasibility and accuracy of the effort estimate, but it is not a factor that determines the effort estimate. Effort estimate is the amount of work required to complete the testing activities, measured in terms of person-hours, person-days, or person-months2.

The other options are correct because:

A. Once the test effort is estimated, resources can be identified and a schedule can be drawn up, as they are interrelated aspects of the test planning process3. Resources are the people, tools, equipment, and facilities needed to perform the testing activities4. Schedule is the time frame and sequence of the testing activities, aligned with the project milestones and deadlines5.

B. Effort estimate can be inaccurate because the quality of the product under tests is not known, as it affects the number and severity of the defects that may be found and the rework that may be needed to fix them6. Quality is the degree to which the software product satisfies the specified requirements and meets the needs and expectations of the users and clients7.

D. Experience based estimation is one of the estimation techniques, which relies on the judgment and expertise of the testers and other project stakeholders to estimate the test effort based on similar projects or tasks done in the past. Experience based estimation can be useful when there is a lack of historical data, formal methods, or detailed information about the software product and the testing activities.

References =

1 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 154

2 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 155

3 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 156

4 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 157

5 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 158

6 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 159

7 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 16

[8] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 160

[9] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 161

Boundary Value Analysis (BVA) is a software testing technique in which tests are designed to include values at the boundaries. The concept is to focus on the boundaries since errors tend to occur at the edges of input ranges rather than in the middle.

Given the problem statement:

Up to $100.00 = 2%

$100.01 to $500.00 = 4%

$500.01 to $1,000.00 = 5%

Above $1,000.00 = 7%

Two-point boundary value analysis means testing the two boundaries of each range.

For each range:

The boundaries for "Up to $100.00" would be $100.00 and $100.01.

The boundaries for "$100.01 to $500.00" would be $100.00 and $500.00.

The boundaries for "$500.01 to $1,000.00" would be $500.00 and $1,000.00.

The boundaries for "Above $1,000.00" would be $1,000.00 and $1,000.01.

Now, let's examine the options:

A. $5.00, $100.00, $499.99, $1,000.00, $1,000.01

Missing $100.01 and $500.01.

B. $100.00, $100.01, $100.02, $500.00, $999.99

Covers $100.00, $100.01, $500.00, $1000.00, and $1000.01.

C. $100.00, $500.00, $1,000.00, $1,000.01

Missing $100.01 and $500.01.

D. $5.00, $100.00, $500.00, $1,000.01

Missing $100.01 and $500.01.

Given the options, B provides the highest boundary coverage​ (ISTQB not-for-profit association)​​ (Udemy)​.

References:

Certified Tester Foundation Level v4.0

10 Sample Exams ISTQB Foundation Level (CTFL) v4.0

The Waterfall model exemplifies a software development model that does not support the principle of early testing. In the Waterfall model, each phase must be completed before the next begins, which delays testing until after the completion of the earlier phases like requirements gathering and design. This can often result in finding defects later in the development cycle, making them more expensive and time-consuming to fix​ (ISTQB not-for-profit association)​​ (ISTQB not-for-profit association)​.References:

ISTQB® Certified Tester Foundation Level Syllabus v4.0: https://istqb-main-web-prod.s3.amazonaws.com/media/documents/ISTQB_CTFL_Syllabus-v4.0.pdf

ISTQB News Release on CTFL v4.0: https://www.istqb.org/news/posts/istqb-releases-certified-tester-foundation-level-v40-ctfl/

Analyzing and removing the cause of failures is not an objective of testing, but rather a task of development or maintenance. A failure is an event or behavior that deviates from the expected or specified result of a system under test. A failure is caused by an error (also known as a mistake or a fault) in the software code, design, or specification. Analyzing and removing the cause of failures is a process of locating and fixing errors in the software code, design, or specification, which is also known as debugging or defect resolution. Analyzing and removing the cause of failures does not aim to find or report defects, but rather to correct or prevent them. The other options are objectives of testing. Finding defects is one of the main objectives of testing, as it helps to improve the quality and reliability of the software product. Providing information for decision-making is another objective of testing, as it helps to support decision making and risk management. Gaining confidence about the level of quality of the software is another objective of testing, as it helps to assure that the software product meets its requirements and customer or user needs and expectations. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, page 3.

A failure is an event in which a component or system does not perform a required function within specified limits1. A requirement is a condition or capability needed by a user to solve a problem or achieve an objective2. In this case, the requirement is that the diagnostics tests should execute in less than 2 seconds. Therefore, any event that violates this requirement is a failure. The only option that clearly violates this requirement is B. The diagnostic tests take too much time to execute. If the diagnostic tests take more than 2 seconds to complete, then they do not meet the specified limit and thus fail. The other options are not necessarily failures related to the specified requirement. Option A. The diagnostic tests fail to start after a system reset is a failure, but not related to the time limit. It is related to the functionality of the self-diagnostics module. Option C. The diagnostic tests that measure the speed of the memory, fail is also a failure, but not related to the time limit. It is related to the accuracy of the memory tests. Option D. The diagnostic tests fail due to incorrect implementation of the test code is also a failure, but not related to the time limit. It is related to the quality of the test code. References = ISTQB® Certified Tester Foundation Level Syllabus v4.0, Requirements Engineering Fundamentals.

Statement D is correct. According to the ISTQB CTFL syllabus, both black-box test techniques (which focus on testing without internal knowledge of the application) and experience-based test techniques (which rely on testers' experience and intuition) can be applied to both functional and non-functional testing. Functional testing is concerned with what the system does, whereas non-functional testing looks at how the system performs under certain conditions. These techniques are versatile and can be employed to address both these aspects​​.

Independent testing is testing performed by a person or group that is independent of the development team. Independent testing can have various degrees of independence, ranging from testers who are part of the same organization as developers to testers who are external contractors or consultants. Independent testing can have various benefits, such as reducing bias, increasing objectivity, improving quality, or providing different perspectives. Independent testing is not necessary because developers don’t know any testing, as this is a wrong and disrespectful statement. Developers can perform various types of testing, such as unit testing, component testing, or integration testing. However, independent testing can complement developer testing by providing additional levels of verification and validation, such as system testing, acceptance testing, or non-functional testing. Verified References: [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer], Chapter 2, page 16-17.

The purpose of a review is to find defects and improve the quality of the work product, not to criticize or blame the author. Reporting defects objectively means describing them factually and constructively, without using negative or emotional language that could offend the author or damage their motivation. This way, the author can take the feedback positively as an effort at improving the product and not as a personal assault. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, page 138.

Defect clustering is a testing principle that states that a small number of modules contain most of the defects detected during pre-release testing, or are responsible for most of the operational failures. Defect clustering can be explained by Pareto’s principle (also known as the 80-20 rule), which states that approximately 80% of the problems are found in 20% of the modules. Defect clustering suggests a change to the current test strategy for the next test cycle, as it implies that more effort should be allocated to test the modules that have shown high defect density or criticality. Pesticide paradox is another testing principle that states that if the same tests are repeated over and over again, eventually they will no longer find any new defects. Pesticide paradox suggests a change to the current test strategy for the next test cycle, but not based on defect clustering, but rather on test diversity and coverage. Early testing is a testing principle that states that testing activities should start as early as possible in the software development life cycle and should be focused on defined objectives. Early testing does not suggest a change to the current test strategy for the next test cycle, but rather a proactive approach to prevent defects from occurring or propagating. Absence-of-errors fallacy is a testing principle that states that finding and fixing defects does not help if the system built is unusable and does not fulfill the users’ needs and expectations. Absence-of-errors fallacy does not suggest a change to the current test strategy for the next test cycle, but rather a focus on quality attributes and user requirements. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, Chapter 1, page 9-10.

Traceability is the ability to trace the relationships between the items of the test basis, such as the requirements, the design, the risks, etc., and the test artifacts, such as the test cases, the test results, the defects, etc. Traceability can provide various benefits for the testing process, such as improving the test coverage, the test quality, the test efficiency, and the test communication. However, not all the statements given are true about the value of maintaining traceability between the test basis and test work products. The statement that is not true is option C, which says that test objectives should be the same for all test levels, although the number of tests designed at various levels can vary significantly. This statement is false, because test objectives are the goals or the purposes of testing, which can vary depending on the test level, the test type, the test technique, the test environment, the test stakeholder, etc. Test objectives can be defined in terms of the test basis, the test coverage, the test quality, the test risk, the test cost, the test time, etc. Test objectives should be specific, measurable, achievable, relevant, and time-bound, and they should be aligned with the project objectives and the quality characteristics. Test objectives should not be the same for all test levels, as different test levels have different focuses, scopes, and perspectives of testing, such as component testing, integration testing, system testing, and acceptance testing. The other statements are true about the value of maintaining traceability between the test basis and test work products, such as:

Traceability can be useful for assessing the impact of a change to a test basis item on the corresponding tests: This statement is true, because traceability can help to identify which tests are affected by a change in the test basis, such as a new requirement, a modified design, a revised risk, etc., and to determine the necessary actions to update, re-execute, or re-evaluate the tests. Traceability can also help to estimate the effort, the cost, and the time needed to implement the change and to verify its impact on the software system.

Traceability can be useful for determining how many test basis items are covered by the corresponding tests: This statement is true, because traceability can help to measure the test coverage, which is the degree to which the test basis is exercised by the test cases. Traceability can help to identify which test basis items are covered, partially covered, or not covered by the tests, and to evaluate the adequacy, the completeness, and the effectiveness of the testing process. Traceability can also help to identify the gaps, the overlaps, or the redundancies in the test coverage, and to prioritize, optimize, or improve the test cases.

Traceability can be useful to support the needs required by the auditing of testing: This statement is true, because traceability can help to provide evidence, documentation, and justification for the testing activities, results, and outcomes. Traceability can help to demonstrate that the testing process follows the standards, the regulations, the policies, and the best practices that are applicable to the software system, the project, or the organization. Traceability can also help to verify that the testing process meets the expectations, the needs, and the satisfaction of the users and the stakeholders. References: ISTQB Certified Tester Foundation Level (CTFL) v4.0 sources and documents:

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 1.2.2, Testing Policies, Strategies, and Test Approaches1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.1, Test Planning1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.2, Test Monitoring and Control1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.1.3, Test Analysis and Design1

ISTQB® Glossary of Testing Terms v4.0, Traceability, Test Basis, Test Artifact, Test Objective, Test Level, Test Coverage, Test Quality, Test Risk, Test Cost, Test Time2

Failures can be caused by defects, but also by environmental conditions. A failure is an event in which the software system does not perform a required function or performs a function incorrectly, according to the expected behavior. A defect is a flaw in the software system or a deviation from the requirements or the specifications, that may cause a failure. However, not all failures are caused by defects, as some failures may be caused by environmental conditions, such as hardware malfunctions, network interruptions, power outages, incompatible configurations, etc. Environmental conditions are factors that affect the operation of the software system, but are not part of the software system itself. The other statements are false, because:

A defect does not always produce a failure, while a bug always produces a failure. This statement is false, because a defect may or may not produce a failure, depending on the inputs, the outputs, the states, or the scenarios of the software system, and a bug is just another term for a defect, so it has the same possibility of producing a failure as a defect. For example, a defect in a rarely used feature or a hidden branch of the code may never produce a failure, while a defect in a frequently used feature or a critical path of the code may produce a failure often. A bug is not a different concept from a defect, but rather a synonym or a colloquial term for a defect, so it has the same definition and implications as a defect.

A defect may cause a failure which, when occurring, always causes an error. This statement is false, because an error is not a consequence of a failure, but rather a cause of a defect. An error is a human action or a mistake that produces a defect in the software system, such as a typo, a logic flaw, a requirement misunderstanding, etc. An error is not observable in the software system, but rather in the human mind or the human work products, such as the code, the design, the documentation, etc. A failure is not a cause of an error, but rather a result of a defect, which is a result of an error. For example, an error in the code may cause a defect in the software system, which may cause a failure in the software behavior.

Bugs are defects found during component testing, while failures are defects found at higher test levels. This statement is false, because bugs and failures are not different types of defects, but rather different terms for defects and their manifestations. As mentioned before, bugs are just another word for defects, and failures are the events in which the software system does not perform as expected due to defects. Bugs and failures can be found at any test level, not only at component testing or higher test levels. Test levels are the stages of testing that correspond to the levels of integration of the software system, such as component testing, integration testing, system testing, and acceptance testing. Defects and failures can occur and be detected at any test level, depending on the test objectives, the test basis, the test techniques, and the test environment. References: ISTQB Certified Tester Foundation Level (CTFL) v4.0 sources and documents:

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 1.1.2, Testing and Quality1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 1.2.1, Testing Principles1

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 1.3.1, Testing in Software Development Lifecycles1

ISTQB® Glossary of Testing Terms v4.0, Failure, Defect, Bug, Environmental Condition, Error, Test Level2

Static testing is a form of testing that does not involve executing the software, but rather analyzing it for defects, errors, or violations of standards. Static testing can be applied to any software development product, including requirements specifications, design specifications, code, test cases, test plans, user manuals, etc. Static testing can be done by using various techniques such as reviews, inspections, walkthroughs, checklists, static analysis tools, etc. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, page 7.

 If a program got 100% decision coverage in a test, then it is guaranteed that every executable statement is covered. Decision coverage (also known as branch coverage) is a type of structural coverage (also known as white-box coverage) that measures how many decision outcomes have been exercised by a test suite. A decision outcome is a possible result of a decision point (such as an if-then-else statement) in a program’s code. Decision coverage requires that each decision point has both true and false outcomes executed at least once by a test suite. Decision coverage implies statement coverage, which is another type of structural coverage that measures how many executable statements have been executed by a test suite. Statement coverage requires that each executable statement is executed at least once by a test suite. Therefore, if a program got 100% decision coverage in a test, then it also got 100% statement coverage in a test, which means that every executable statement is covered. The other options are not guaranteed to be true if a program got 100% decision coverage in a test. Every output equivalence class has been tested and every input equivalence class has been tested are not guaranteed to be true if a program got 100% decision coverage in a test, because equivalence classes are based on functional requirements or specifications, not on code structure or logic. Equivalence classes are used in specification-based testing (also known as black-box testing), which is a type of testing that does not consider the internal structure or implementation of the system under test. Decision coverage is used in structure-based testing (also known as white-box testing), which is a type of testing that considers the internal structure or implementation of the system under test. Therefore, achieving 100% decision coverage does not imply achieving 100% equivalence class coverage. The “dead” code has not been covered is not guaranteed to be true if a program got 100% decision coverage in a test, because dead code (also known as unreachable code) is code that can never be executed due to logical errors or design flaws. Dead code can reduce readability and maintainability of the code, as well as increase complexity and size. Decision coverage does not account for dead code, as it only considers the decision outcomes that are possible to execute. Therefore, achieving 100% decision coverage does not imply that the dead code has not been covered. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, page 36.

This answer is correct because Behavior-Driven Development (BDD) is a test-first approach, where tests that express a shared understanding from stakeholders of how the application is expected to work, are first written in business-readable language (following the Given/When/Then format), and then made executable to drive development. BDD is a collaborative approach that involves testers, developers, business analysts, product owners, and other stakeholders in defining the expected behavior of the application using scenarios that describe the preconditions, actions, and outcomes of the application. BDD scenarios are written using a domain-specific language (DSL) that can be translated into executable test cases using tools such as Cucumber or SpecFlow. BDD aims to improve communication, collaboration, and feedback among the team members, and to deliver software that meets the customer’s needs and expectations. References: ISTQB Glossary of Testing Terms v4.0, ISTQB Foundation Level Syllabus v4.0, Section 3.1.1.4

, Requirements Engineering Fundamentals.

According to the ISTQB CTFL syllabus, a defect is a deviation from the expected result which in this scenario is the incorrect discount applied to the customers. The root cause, as per the ISTQB definition, is the originating cause of a defect, which in this case is the incorrect requirement stating 50% instead of 5%. Therefore, the incorrect requirement is the root cause and the customer receiving the wrong discount is the effect of this root cause.References:ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 1.4.3 "Defects, Root Causes, and Effects".

A correct list of boundary values for the P input should include the minimum and maximum values of the valid range (15 and 350), as well as the values just below and above the boundaries (14 and 351). Boundary value analysis is a test design technique that involves testing the values at or near the boundaries of an input domain or output range, as these values are more likely to cause errors than values in the middle. Option B satisfies this condition, as it has all four boundary values (14, 15, 350, 351). Option A has two values from the same equivalence class (1000 and 99999), option C has two values outside the range (999 and 100000), and option D has no boundary values at all. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, page 34.

Regression testing is the re-running of functional and non-functional tests to ensure that previously developed and tested software still performs as expected after a change1 It does not involve retesting of a fixed defect, testing of new functionality, or applying only to functional testing. Tests that are used for regression testing should be repeatable, because they are used to verify the stability of the software after each change2 References = ISTQB Certified Tester Foundation Level (CTFL) v4.0 Syllabus, Chapter 4, Section 4.2.2, Page 291; ISTQB Glossary of Testing Terms v4.0, Page 292

To apply one-dimensional equivalence partitioning to the ID requirement, we need to consider each condition individually:

Length of the ID: Valid partitions (5-10 characters), Invalid partitions (less than 5, more than 10) = 3 partitions.

Type of characters: Valid partitions (alphanumeric), Invalid partitions (non-alphanumeric) = 2 partitions.

First character: Valid partitions (letter), Invalid partitions (non-letter) = 2 partitions. Adding these partitions, we get a total of 3 (length) + 2 (character type) + 2 (first character) = 7 partitions. Thus, the correct answer is A​​.

A formal review is a type of review that follows a defined process with formal entry and exit criteria and roles and responsibilities for participants. A formal review can have various roles involved, such as manager, moderator, author, reviewer and scribe. The manager responsibilities in formal review include all except one of the following:

Planning the review (correct responsibility)

Determines if the review objectives have been met (incorrect responsibility)

Decide on the execution of reviews (correct responsibility)

Allocate time for review (correct responsibility) The responsibility of determining if the review objectives have been met belongs to the moderator role, not to the manager role. Verified References: [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer], Chapter 3, page 28-29.

The following statements about risk-based testing are correct:

II) Tests should be prioritized to find tie critical detects as early as possible. Risk-based testing involves prioritizing tests based on risk level, which reflects both the likelihood and impact of defects or failures. Tests with higher risk level should be executed earlier than tests with lower risk level, in order to find and fix critical defects as soon as possible.

III) Non-testing activities may also help to reduce risk. Risk-based testing does not only involve testing activities, but also other activities that can help mitigate risks, such as reviews, inspections, audits, simulations or prototyping.

Use cases describe a system's behavior as it responds to a request from a user. They typically consist of various scenarios, such as basic flow, alternative flow, and exceptional flow, which represent possible behaviors when a user interacts with the system. When deriving test cases from use cases, it is important to cover these different types of user behaviors.Test cases should be designed to verify how the system behaves during each of these scenarios. This ensures that the system operates correctly for normal and error conditions encountered by human users or systems interacting with the application. Thus, test cases derived from use cases aim to cover basic, exceptional, and alternative flows, ensuring comprehensive coverage.References:

ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 4.2.4.

In defect reporting, the attribute that indicates the degree of impact that the defect has on the system is the severity. Severity reflects the seriousness of the defect in terms of its impact on the operation of the system, ranging from minor issues that do not significantly affect the system's functionality to critical defects that can cause system failure. Therefore, option B is the correct answer​​.

In a planning poker session, if there is a significant difference in the estimations, it indicates that there may be misunderstandings or different perspectives on the complexity of the user story. According to the agile principles, the team should discuss these differences to reach a common understanding. The goal is to ensure that all team members have a shared understanding of the user story's scope and complexity before finalizing the estimate​​.

One of the common risks associated with test automation tools is the underestimation of the effort required to maintain test scripts. Test scripts can become outdated or broken due to changes in the application, requiring significant effort to update and maintain them. This risk is highlighted in the ISTQB CTFL syllabus under the discussion of the benefits and risks of test automation.

References: ISTQB CTFL Syllabus, Section on test tools and automation.

Branch coverage is a type of structural coverage metric that measures the percentage of branches or decision outcomes that are executed by the test cases. A branch is a point in the code where the control flow can take two or more alternative paths based on a condition. For example, an if-else statement is a branch that can execute either the if-block or the else-block depending on the evaluation of the condition. Branch coverage ensures that each branch is taken at least once by the test cases, and thus reveals the behavior of the software under different scenarios. Branch coverage is also known as decision coverage or all-edges coverage.

Branch coverage is suitable for testing the cases where a specific action is not allowed, because it can verify that the test cases cover all the possible outcomes of the conditions that determine the action. For example, if the program has a condition that checks if the manufacturing stage can be stopped, then branch coverage can ensure that the test cases cover both the cases where the stage can be stopped and where it cannot be stopped. This way, branch coverage can help identify any missing or incorrect branches that may lead to undesired or unsafe actions.

The other options are not correct because they are not suitable for testing the cases where a specific action is not allowed. Code coverage is a general term that encompasses various types of coverage metrics, such as statement coverage, branch coverage, data flow coverage, etc. Code coverage does not specify which type of coverage metric is used for the analysis. Data flow coverage is a type of structural coverage metric that measures the percentage of data flow paths that are executed by the test cases. A data flow path is a sequence of statements that define, use, or kill a variable. Data flow coverage is useful for testing the correctness and completeness of the data manipulation in the software, but not for testing the conditions that determine the actions. Statement coverage is a type of structural coverage metric that measures the percentage of statements or lines of code that are executed by the test cases. Statement coverage ensures that each statement is executed at least once by the test cases, but it does not reveal the behavior of the software under different scenarios. Statement coverage is a weaker criterion than branch coverage, because it does not account for the branches or decision outcomes in the code. References = ISTQB Certified Tester Foundation Level (CTFL) v4.0 syllabus, Chapter 4: Test Techniques, Section 4.3: Structural Testing Techniques, Pages 51-54.

Entry and exit criteria are used to determine when to start and stop testing, respectively.

Entry Criteria:

These are conditions that should be met before testing begins.

Examples:

2. The test automation tool has been installed and properly configured

4. The performance test environment has been set-up and is available

5. The user stories have proper acceptance criteria defined

Exit Criteria:

These are conditions that should be met before testing concludes.

Examples:

1. A defined level of code coverage has been achieved

3. The number of unresolved defects is within the predefined limit

6. The testing budge​ (ISTQB not-for-profit association)​ spent and the project sponsor bears the risk of not testing any further

According to the ISTQB Certified Tester Foundation Level (CTFL) v4.0 syllabus, these criteria help in effectively managing the testing process【6†source】.

References:

Certified Tester Foundation Level v4.0

ISTQB Foundation Level Syllabus 4.0 (2023)

The test leader is the person who is responsible for planning, monitoring, and controlling the test activities and resources in a test project. The test leader should have the best knowledge of the test objectives, scope, risks, resources, schedule, and quality criteria. The test leader should also be aware of the test automation criteria, such as the execution frequency, the test support, the team education, the roles and responsibilities, and the devs and testers collaboration1. Based on these factors, the test leader can decide which tests are suitable for automation and which are not, and prioritize them accordingly. The test leader can also coordinate with the test automation engineers, the developers, and the stakeholders to ensure the alignment of the test automation strategy with the test project goals and expectations. References = ISTQB Certified Tester Foundation Level (CTFL) v4.0 Syllabus, Chapter 2, Section 2.3.1, Page 152; ISTQB Glossary of Testing Terms v4.0, Page 403; ISTQB Certified Tester Foundation Level (CTFL) v4.0 Syllabus, Chapter 6, Section 6.1.1, Page 514; Top 8 Test Automation Criteria You Need To Fulfill - QAMIND1

 The V-model is a software development life cycle model that defines four test levels that correspond to four development phases: component (unit) testing with component design, integration testing with architectural design, system testing with system requirements, and acceptance testing with user requirements. The V-model emphasizes the importance of verifying and validating each phase of development with a corresponding level of testing, and ensuring that the test objectives, test basis, and test artifacts are aligned and consistent across the test levels. Therefore, an organization that wants to follow the V-model cannot do away with integration testing, as it would break the symmetry and completeness of the V-model, and compromise the quality and reliability of the software or system under test. Integration testing is a test level that aims to test the interactions and interfaces between components or subsystems, and to detect any defects or inconsistencies that may arise from the integration of different parts of the software or system. Integration testing is essential for ensuring the functionality, performance, and compatibility of the software or system as a whole, and for identifying and resolving any integration issues early in the development process. Skipping integration testing would increase the risk of finding serious defects later in the test process, or worse, in the production environment, which would be more costly and difficult to fix, and could damage the reputation and credibility of the organization. Therefore, the correct answer is D.

The other options are incorrect because:

A. It is not allowed as organizations can decide on the test levels to do depending on the context of the system under test. While it is true that the choice and scope of test levels may vary depending on the context of the system under test, such as the size, complexity, criticality, and risk level of the system, the organization cannot simply ignore or skip a test level that is defined and required by the chosen software development life cycle model. The organization must follow the principles and guidelines of the software development life cycle model, and ensure that the test levels are consistent and coherent with the development phases. If the organization wants to have more flexibility and adaptability in choosing the test levels, it should consider using a different software development life cycle model, such as an agile or iterative model, that allows for more dynamic and incremental testing approaches.

B. It is not allowed because integration testing is not an important test level and can be dispensed with. This statement is false and misleading, as integration testing is a very important test level that cannot be dispensed with. Integration testing is vital for testing the interactions and interfaces between components or subsystems, and for ensuring the functionality, performance, and compatibility of the software or system as a whole. Integration testing can reveal defects or inconsistencies that may not be detected by component (unit) testing alone, such as interface errors, data flow errors, integration logic errors, or performance degradation. Integration testing can also help to verify and validate the architectural design and the integration strategy of the software or system, and to ensure that the software or system meets the specified and expected quality attributes, such as reliability, usability, security, and maintainability. Integration testing can also provide feedback and confidence to the developers and stakeholders about the progress and quality of the software or system development. Therefore, integration testing is a crucial and indispensable test level that should not be skipped or omitted.

C. It is not allowed because integration testing is a very important test level and ignoring it means definite poor product quality. This statement is partially true, as integration testing is a very important test level that should not be ignored, and skipping it could result in poor product quality. However, this statement is too strong and absolute, as it implies that integration testing is the only factor that determines the product quality, and that ignoring it would guarantee a poor product quality. This is not necessarily the case, as there may be other factors that affect the product quality, such as the quality of the requirements, design, code, and other test levels, the effectiveness and efficiency of the test techniques and tools, the competence and experience of the developers and testers, the availability and adequacy of the resources and environment, the management and communication of the project, and the expectations and satisfaction of the customers and users. Therefore, while integration testing is a very important test level that should not be skipped, it is not the only test level that matters, and skipping it does not necessarily mean definite poor product quality, but rather a higher risk and likelihood of poor product quality.

References = ISTQB Certified Tester Foundation Level Syllabus, Version 4.0, 2018, Section 2.3, pages 16-18; ISTQB Glossary of Testing Terms, Version 4.0, 2018, pages 38-39; ISTQB CTFL 4.0 - Sample Exam - Answers, Version 1.1, 2023, Question 104, page 36.

State transition testing is a black-box testing technique used to analyze the behavior of a system by examining the transitions between different states in response to events. In state transition testing, a state table or diagram is used to represent the states of a system and the transitions between these states triggered by events.

Option D is correct because in state transition testing, all transitions between states should be explicitly shown in the state table. This includes valid transitions that the system is expected to make under normal operation and, where relevant, invalid transitions that should be tested to ensure the system handles unexpected or erroneous inputs gracefully. The state table provides a comprehensive view of how the system should behave, making it possible to create tests that cover all defined transitions.

An oracle is a mechanism or source that can provide the expected result for a given test input or situation. Sometimes old version of a product can be used as an oracle, if it is assumed that the old version behaves correctly for the test cases that are executed on the new version. This is also known as back-to-back testing. Oracles do not help in reproducing the irreproducible bugs, as they only provide the expected results, not the actual results. Oracles are not derived from the design, but from the requirements or specifications. Oracles cannot be generated automatically using data generators, as data generators only provide test inputs, not test outputs. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, page 9.

Testing is necessary for various reasons, such as:

To detect defects and failures that may affect the quality, performance, reliability or security of a software product or system

To verify that a software product or system meets its specified requirements, expectations and standards

To validate that a software product or system fulfills its intended purpose and satisfies its stakeholders’ needs

To provide information and feedback about the status and risks of a software product or system

To comply with regulations or contractual obligations that mandate testing for certain types of software products or systems The following statements describe some reasons why testing is necessary:

A) The customer decided that 100% branch coverage shall be achieved. This is a reason why testing is necessary, as it reflects a contractual obligation or a quality standard that requires testing to measure and achieve a certain level of code coverage.

C) For avionics and pharmaceutical systems software testing is mandated by standards. This is a reason why testing is necessary, as it reflects a regulation or a compliance requirement that mandates testing for certain types of software products or systems that have high safety or security risks.

D) The risks associated with delivering the system are far higher than the cost of testing. This is a reason why testing is necessary, as it reflects a risk-based approach that considers testing as an investment to reduce the probability and impact of potential failures or defects. The following statement does not describe a reason why testing is necessary:

B) The acquisition of test automation tools was based on the assumption that it will be used m all projects. This is not a reason why testing is necessary, as it reflects a business decision or a resource allocation that does not justify the need or purpose of testing. Test automation tools are not always suitable or beneficial for all projects, and testing can be performed with or without test automation tools. Verified References: [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer], Chapter 1, page 5-6.

The testing of software does not demonstrate the absence of defects, but rather the presence of defects or the conformance of the software to the specified requirements1. Testing can never prove that the software is defect-free, as it is impossible to test all possible scenarios, inputs, outputs, and behaviors of the software2. Testing can only provide a level of confidence in the quality of the software, based on the coverage, effectiveness, and efficiency of the testing activities3.

The other options are correct because:

A. Properly designed tests that pass reduce the level of risk in a system, as they verify that the system meets the expected quality attributes and satisfies the needs and expectations of the users and clients4. Risk is the potential for loss or harm due to the occurrence of an undesirable event5. Testing can help to identify, analyze, prioritize, and mitigate the risks associated with the software product and project6.

C. Software testing identifies defects, which can be used to improve development activities, as they provide feedback on the quality of the software and the effectiveness of the development processes7. Defects are flaws or errors in the software that cause it to deviate from the expected or required results or behavior. Testing can help to detect, report, track, and resolve the defects, and prevent them from recurring in the future.

D. Performing a review of the requirement specifications before implementing the system can enhance quality, as it can ensure that the requirements are clear, complete, consistent, testable, and aligned with the needs and expectations of the users and clients. Requirements are the specifications of what the software should do and how it should do it. Testing can help to validate that the requirements are met by the software, and verify that the software is implemented according to the requirements.

References =

1 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 10

2 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 11

3 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 12

4 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 13

5 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 97

6 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 98

7 ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 14

[8] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 15

[9] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 16

[10] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 17

[11] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 18

[12] ISTQB® Certified Tester Foundation Level Syllabus v4.0, 2023, p. 19

According to the ISTQB Certified Tester Foundation Level (CTFL) v4.0, the life cycle of a defect typically follows a sequence from its discovery to its closure. In the provided figure, it starts with S0 (New), moves to S1 (Assigned), then to S2 (Resolved), followed by S3 (Verified). If the defect is not fixed, it can be Re-opened (S5) and goes back for verification (S3). Once verified, it is Closed (S4). References: ISTQB Certified Tester Foundation Level (CTFL) v4.0 Syllabus, Section 1.4.3, Page 17.

Exploratory testing is an approach to testing that emphasizes learning, test design and test execution at the same time. Exploratory testing relies on the tester’s skills, creativity and intuition to explore the software under test and discover defects. Exploratory testing is suitable for a new project with little documentation and high probability for bugs, as it can help uncover unknown requirements, assumptions and risks. Exploratory testing is not requirements based testing, which is an approach to testing that derives test cases from documented requirements or specifications. Requirements based testing is not feasible for a new project with little documentation, as it requires clear and complete requirements to be available. Exploratory testing is not metric based approach, which is an approach to testing that uses quantitative measures to monitor and control the testing process and evaluate the quality of the software product. Metric based approach is not effective for a new project with high probability for bugs, as it may not capture all aspects of quality and may lead to false confidence or unrealistic expectations. Exploratory testing is not regression testing, which is an approach to testing that verifies that previously tested software still performs correctly after changes. Regression testing is not relevant for a new project with no previous versions or baselines. Verified References: [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer], Chapter 5, page 47-48.

Test-Driven Development (TDD) emphasizes writing tests before code and includes refactoring as a key practice to improve both the tests and the code. This ensures that the codebase remains clean and maintainable. The ISTQB CTFL Syllabus v4.0 discusses TDD as a practice that includes writing tests first, coding to satisfy those tests, and then refactoring the code to improve its structure and readability while keeping the tests intact​​.

State transition testing is a black-box testing technique where test cases are designed to cover states and transitions of a state machine.

Given the state model with the following transitions:

PLACED -> IN PRODUCTION

IN PRODUCTION -> CANCELLED

IN PRODUCTION -> SHIPPED

SHIPPED -> INVOICED

INVOICED -> CANCELLED

CANCELLED -> PLACED

To cover all transitions at least once, we need to create a sequence that covers all six transitions.

Option A: IN PRODUCTION -> CANCELLED -> PLACED -> IN PRODUCTION -> CANCELLED -> PLACED- Misses SHIPPED -> INVOICED and INVOICED -> CANCELLED transitions.

Option B: IN PRODUCTION -> SHIPPED -> INVOICED -> CANCELLED -> PLACED -> IN PRODUCTION- Covers all transitions.

Option C: PLACED -> IN PRODUCTION -> SHIPPED -> CANCELLED ​ (ISTQB not-for-profit association)​​ (Udemy)​sses INVOICED -> CANCELLED transition.

Option D: PLACED -> CANCELLED -> PLACED -> CANCELLED -> PLACED -> IN PRODUCTION -> CANCELLED- Misses SHIPPED -> INVOICED and INVOICED -> CANCELLED transitions.

Given these, Option B covers all the transitions【6†source】【9†source】.

References:

Certified Tester Foundation Level v4.0

10 Sample Exams ISTQB Foundation Level (CTFL) v4.0

This answer is correct because test implementation is the activity where test work products, such as test cases, test data, test scripts, test harnesses, test stubs, or virtual services, are created and verified. Test implementation also involves setting up the test environment and preparing the test execution schedule. A virtual service emulating a real third-party service and the automated test scripts that interact with that service are examples of test work products that are typically created during test implementation. References: ISTQB Glossary of Testing Terms v4.0, ISTQB Foundation Level Syllabus v4.0, Section 2.2.2.3

The key principles of software testing include: i. Testing shows the presence of defects, not their absence. iv. Defects cluster together. v. Testing is context dependent. vi. Beware of the pesticide paradox. vii. Absence of errors is a fallacy. These principles highlight the importance of recognizing the limitations and context of testing, as well as the potential for repeated tests to become less effective​​.

Statements II, III and V are true about test reports. Test reports are documents that provide information on the results and status of testing activities for a given period or phase. Test reports should give stakeholders information as basis for decisions, such as whether to release the software product, whether to continue testing, whether to change the scope or priorities of testing, etc. Test reports should summarize what happened through a period of testing, such as what test cases were executed, what defects were found, what risks were identified, what issues were encountered, what achievements were made, etc. Test reports should include information about remaining risks, such as what defects are still open, what test cases are still pending, what functionalities are still untested, what uncertainties are still unresolved, etc. Statements I and IV are not true about test reports. Test reports do not need to be approved by the test team, the development team, or the customer, unless it is specified by the test policy or the test plan. Test reports only need to be reviewed and verified by the test leader or the test manager before being distributed to the intended recipients. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, page 141.

The ISTQB fundamental test process consists of five main phases, as described in the ISTQB Foundation Level Syllabus, Version 4.0, 2018, Section 2.2, page 15:

Test planning and control: This phase involves defining the test objectives, scope, strategy, resources, schedule, risks, and metrics, as well as monitoring and controlling the test activities and results throughout the test process.

Test analysis and design: This phase involves analyzing the test basis (such as requirements, specifications, or user stories) to identify test conditions (such as features, functions, or scenarios) that need to be tested, and designing test cases and test procedures (such as inputs, expected outcomes, and execution steps) to cover the test conditions. This phase also involves evaluating the testability of the test basis and the test items (such as software or system components), and selecting and implementing test techniques (such as equivalence partitioning, boundary value analysis, or state transition testing) to achieve the test objectives and optimize the test coverage and efficiency.

Test implementation and execution: This phase involves preparing the test environment (such as hardware, software, data, or tools) and testware (such as test cases, test procedures, test data, or test scripts) for test execution, and executing the test procedures or scripts according to the test plan and schedule. This phase also involves logging the outcome of test execution, comparing the actual results with the expected results, and reporting any discrepancies as incidents (such as defects, errors, or failures).

Evaluating exit criteria and reporting: This phase involves checking if the planned test activities have been completed and the exit criteria (such as quality, coverage, or risk levels) have been met, and reporting the test results and outcomes to the stakeholders. This phase also involves making recommendations for the release or acceptance decision based on the test results and outcomes, and identifying any residual risks (such as known defects or untested areas) that need to be addressed or mitigated.

Test closure activities: This phase involves finalizing and archiving the testware and test environment for future reuse, and evaluating the test process and the test project against the test objectives and the test plan. This phase also involves identifying any lessons learned and best practices, and communicating the findings and suggestions for improvement to the relevant parties.

References = ISTQB Certified Tester Foundation Level Syllabus, Version 4.0, 2018, Section 2.2, page 15; ISTQB Glossary of Testing Terms, Version 4.0, 2018, pages 37-38; ISTQB CTFL 4.0 - Sample Exam - Answers, Version 1.1, 2023, Question 88, page 32.

Equivalence partitioning and boundary value analysis are test design techniques that are most appropriate for testing the login page of a web site. The page contains fields for user name and password, which are input values that can be divided into partitions of equivalent data. Equivalence partitioning is a technique that divides the input data and output results of a software component into partitions of equivalent data. Each partition should contain data that is treated in the same way by the component. Equivalence partitioning can be used to reduce the number of test cases by selecting one representative value from each partition. Boundary value analysis is a technique that tests boundary values between partitions of equivalent data. Boundary values are values at the edge of an equivalence partition or at the smallest incremental distance on either side of an edge. Boundary value analysis can be used to detect defects caused by incorrect handling of boundary conditions. For example, for testing the user name field, we can identify two equivalence partitions: valid user name (existing and correct) and invalid user name (non-existing or incorrect). The boundary values for these partitions are the minimum and maximum length of user name allowed by the system.

Decision table testing and state transition testing are not suitable for testing the login page of a web site, as they are more applicable for testing components that have multiple inputs and outputs that depend on logical combinations of conditions or events. Decision table testing is a technique that shows combinations of inputs and/or stimuli (causes) with their associated outputs and/or actions (effects). State transition testing is a technique that models how a system transitions from one state to another depending on events or conditions.

Exploratory testing and statement coverage are not suitable for testing the login page of a web site, as they are more applicable for testing components that require learning, creativity and intuition or structural analysis. Exploratory testing is an approach to testing that emphasizes learning, test design and test execution at the same time. Exploratory testing relies on the tester’s skills, creativity and intuition to explore the software under test and discover defects. Statement coverage is a type of structural testing that measures how many statements in a program have been executed by a test suite. Statement coverage can be used to assess the adequacy or completeness of a test suite.

Decision coverage and fault attack are not suitable for testing the login page of a web site, as they are more applicable for testing components that have complex logic or potential errors. Decision coverage is a type of structural testing that measures how many decision outcomes in a program have been executed by a test suite. Decision coverage can be used to assess the adequacy or completeness of a test suite. Fault attack is a type of functional testing that deliberately introduces faults into a system in order to provoke failures or errors. Verified References: [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer], Chapter 4, page 34-46; Chapter 5, page 47-48.

 A correct list of boundary values for the age input should include the minimum and maximum values of each age group (0, 12, 13, 18), as well as the values just below and above each boundary (-1, 19). Boundary value analysis is a test design technique that involves testing the values at or near the boundaries of an input domain or output range, as these values are more likely to cause errors than values in the middle. Option A satisfies this condition, as it has all six boundary values (-1, 0, 12, 13, 18, 19). Option B has two values from the same equivalence class (12 and 13), option C has only four boundary values (0, 12, 18, 19), and option D has no boundary values at all. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, page 34.

Traceability primarily refers to the ability to link test cases back to their sources in the test basis, such as requirements or design documents. This linkage allows for the determination of coverage, impact analysis, and maintaining consistency across test documentation. However, traceability does not directly enable the application of experience-based test techniques, which are more about using the tester's intuition and experience. The ISTQB CTFL Syllabus v4.0 does not state that traceability enables experience-based techniques, making option B the false statement​​.

Risk level is determined by the combination of two factors: the likelihood of an event occurring and the impact or harm that could result from that event. This approach allows risks to be prioritized based on their potential effect on the project or system. The likelihood represents the probability of the risk event occurring, while the impact represents the severity of the consequences if the event does happen. This concept is fundamental in risk-based testing and helps guide decision-making during the testing process.References:

ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 1.4.1.

An incident is any event that occurs during testing that requires investigation. An incident report is a document that records the details of an incident. The next step the tester should take prior to recording the deviation is to try to recreate the incident before reporting. This can help confirm that the incident is reproducible and not caused by a random or external factor. This can also help gather more information about the incident, such as the steps to reproduce it, the expected and actual results, the severity and priority of the incident, or any screenshots or logs that can illustrate the incident. Trying to identify the code fragment causing the problem is not the next step the tester should take prior to recording the deviation, as this is a debugging activity that is usually performed by developers after receiving the incident report. Sending an email to the developer and not reporting the bug is not the next step the tester should take prior to recording the deviation, as this is an informal and unstructured way of communicating incidents that can lead to confusion, inconsistency or loss of information. Reporting the incident as is without any further action is not the next step the tester should take prior to recording the deviation, as this can result in incomplete or inaccurate incident reports that can hamper the investigation and resolution of incidents. Verified References: A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer, Chapter 3, page 32-33.

A project risk relates to potential issues that could affect the overall success of the project. Among the options provided, the risk that "Team members' skills may not be sufficient for the assigned work" is clearly a project risk because it pertains to the potential failure of the project due to inadequate skillsets among the team. This risk affects the entire project's ability to meet its objectives.References:

ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 1.4.2.

Good testing practice dictates that each test level (e.g., unit testing, integration testing, system testing) should have distinct test objectives aligned with the phase of the software development lifecycle it addresses. This ensures that testing is effective and relevant at each stage. According to the ISTQB CTFL Syllabus v4.0, establishing clear test objectives that are consistent with the development phase helps in achieving specific goals and improving the overall quality of the software product​​.

In formal reviews, the scribe's role is to collate potential defects and other findings during the review process. This position is crucial as it ensures all observations and defects are recorded accurately, facilitating efficient analysis and resolution of issues identified during the review.References:ISTQB Certified Tester Foundation Level Syllabus v4.0, Section 3.2.4 "Roles and Responsibilities in a Formal Review".

Experience-based test techniques are test design techniques that rely on the experience, knowledge, intuition, and creativity of the testers to identify and execute test cases that are likely to find defects in the software system. Experience-based test techniques are often useful to detect hidden defects that have not been targeted by black-box test techniques, which are test design techniques that use the external behavior and specifications of the software system as the test basis, without considering its internal structure or implementation. Experience-based test techniques can complement black-box test techniques by covering aspects that are not explicitly specified, such as usability, security, reliability, performance, etc. The other statements are false, because:

Experience-based test techniques do not rely on the experience of testers to identify the root causes of defects found by black-box test techniques, but rather to identify the potential sources of defects based on their own insights, heuristics, or exploratory testing. The root causes of defects are usually identified by debugging or root cause analysis, which are activities that involve examining the code or the development process to find and fix the errors that led to the defects.

Some of the most common test basis used by white-box test techniques include the source code, the design documents, the architecture diagrams, and the control flow graphs of the software system. White-box test techniques are test design techniques that use the internal structure and implementation of the software system as the test basis, and aim to achieve a certain level of test coverage based on the code elements, such as statements, branches, paths, etc. User stories, use cases, and business processes are examples of test basis used by black-box test techniques, as they describe the functional and non-functional requirements of the software system from the perspective of the users or the stakeholders.

The primary goal of experience-based test techniques is not to design test cases that can be easily automated using a GUI-based test automation tool, but rather to design test cases that can reveal defects that are not easily detected by other test techniques, such as boundary value analysis, equivalence partitioning, state transition testing, etc. Test automation is the use of software tools to execute test cases and compare actual results with expected results, without human intervention. Test automation can be applied to different types of test techniques, depending on the test objectives, the test levels, the test tools, and the test resources. However, test automation is not always feasible or beneficial, especially for test cases that require human judgment, creativity, or exploration, such as those designed by experience-based test techniques. References: ISTQB Certified Tester Foundation Level (CTFL) v4.0 sources and documents:

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.2.1, Black-box Test Design Techniques

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.2.2, White-box Test Design Techniques

ISTQB® Certified Tester Foundation Level Syllabus v4.0, Chapter 2.2.3, Experience-based Test Design Techniques

ISTQB® Glossary of Testing Terms v4.0, Experience-based Test Technique, Black-box Test Technique, White-box Test Technique, Test Basis, Test Coverage, Test Automation

Regression testing is a type of testing that verifies that previously tested software still performs correctly after changes. Regression testing can help prevent re-opening of defects fixed earlier by ensuring that they do not cause any new failures or side effects. The first recommendation to the company is to verify existing regression test suite are adequate, and augment it, if required, in order to ensure that defects fixed earlier get re-tested in each subsequent build. This can help improve the coverage and effectiveness of regression testing and detect any regression defects as soon as possible. Automating existing test suites may also help reduce the time and effort required for regression testing, but this is not the first recommendation, as automation may not be feasible or cost-effective for all test cases. Analyzing the product modules containing maximum defects and getting them thoroughly tested and defects fixed as a one-time activity may also help reduce the defect density and improve the quality of those modules, but this is not the first recommendation, as it does not address the root cause of re-opening defects fixed earlier. Training or replacing the teams responsible for development and testing of the modules containing maximum number of defects may also help improve their skills or performance, but this is not the first recommendation, as it may not be necessary or appropriate for all teams. Verified References: [A Study Guide to the ISTQB® Foundation Level 2018 Syllabus - Springer], Chapter 2, page 19; Chapter 4, page 45.

In Agile development, an informal review, often referred to as a "buddy check," is a common review type. Informal reviews are unstructured and involve a pair of colleagues reviewing each other’s work to identify defects early and provide immediate feedback. This type of review is less formal than inspections or walkthroughs and is particularly suitable for Agile environments where rapid feedback and flexibility are essential.

References: ISTQB CTFL Syllabus, Section 3.2.4, "Types of Reviews" and Section 2.1.4, "Agile Testing Practices."