ISTQB ISTQB-CTFL Practice Exam Questions & Answers

Explanation

Cost can be regarded as an exit criterion for testing, because it is a factor that affects the profitability and feasibility of the software product. Testing is an investment that aims to improve the quality and reliability of the software product, but it also consumes resources, such as time, money, and human effort. Therefore, testing should be planned and executed in a way that balances the cost and benefit of testing activities. Having cost as an exit criterion helps to avoid spending too much money on testing, which may result in an unprofitable product or a loss of competitive advantage. Cost can also help to prioritize and focus the testing efforts on the most critical and valuable features and functions of the software product. However, cost should not be the only exit criterion for testing, as it may not reflect the true quality and risk level of the software product. Other exit criteria, such as defect rate, test coverage, user satisfaction, etc., should also be considered and defined in the test plan.

The other options are incorrect, because they either deny the importance of cost as an exit criterion, or they make false or unrealistic assumptions about the cost of testing. Option B is incorrect, because the financial value of product quality can be estimated, for example, by using cost-benefit analysis, return on investment, or cost of quality models. Option C is incorrect, because going by cost as an exit criterion does not necessarily constrain the testing project or help achieve the desired quality level. Cost is a relative and variable factor that depends on the scope, complexity, and context of the software product and the testing project. Option D is incorrect, because the cost of testing can be measured effectively, for example, by using metrics, such as test effort, test resources, test tools, test environment, etc.

Explanation

Use case testing is a technique that helps identify test cases that exercise the whole system on a transaction by transaction basis from start to finish. Use cases are descriptions of how users interact with the system to achieve a specific goal. Use case testing is not focused on data flow, but rather on process flow. Use case testing can be performed by professional testers, customers or end users, depending on the context. Use case testing does not require the test cases to be designed by customers or end users, but rather by anyone who has access to the use case specifications. Verified Reference:A Study Guide to the ISTQB Foundation Level 2018 Syllabus - Springer, Chapter 4, page 36.

Explanation

Test planning involves defining the overall approach to testing, including scheduling, resources, and milestones. It is during this phase that the detailed schedule for each testing activity is determined based on estimates, resource availability, and constraints. The ISTQB CTFL Syllabus v4.0 outlines that test planning encompasses the creation of test plans and schedules to ensure that testing activities are properly managed and controlled.

Explanation

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 Reference:A Study Guide to the ISTQB Foundation Level 2018 Syllabus - Springer, Chapter 1, page 9-10.

Explanation Decision table testing requires covering all combinations of conditions to verify the system behaves correctly. With four conditions, you need to minimize the table by removing redundant test cases while maintaining full coverage. The correct approach is one test case where all conditions are satisfied, plus four additional test cases where each single condition fails while others pass. This gives five test cases total and covers all decision rules without unnecessary repetition or testing invalid combinations.

Explanation Two-value boundary value analysis tests the boundaries and one point from valid equivalence classes, plus one point from invalid classes. For the "passed" range of 26-36 and "passed with distinction" of 37-40, you test the boundaries: 25 (invalid, just below 26), 26 (valid boundary), 36 (valid boundary), 37 (valid boundary), and 40 (valid maximum). Including 0 covers the invalid lower boundary comprehensively. This set captures all critical transitions without testing inside the valid ranges.