ISTQB CTFL-2018 Exam Dumps & Practice Test Questions

Question 1:

What best describes the structure and purpose of a test case in software testing?

A. A statement describing what needs to be tested using measurable coverage criteria derived from analyzing test sources
B. A detailed set of preconditions, inputs, actions, expected outcomes, and postconditions, all derived from defined test conditions
C. A document outlining the goals of testing, including timelines and strategies to achieve them
D. A reference used to determine expected outcomes for comparison with the actual system behavior

Correct Answer: B

Explanation:

A test case is an essential part of software testing that provides a specific and repeatable framework for verifying the functionality of a software application. Among the options, B presents the most accurate and complete definition. It emphasizes the five vital components of a test case: preconditions, inputs, actions, expected results, and postconditions, all based on test conditions. This format allows testers to evaluate whether the system behaves as expected under defined scenarios.

Let's assess the other options to understand why they are incorrect:

• Option A describes test conditions rather than a full test case. Test conditions indicate what should be tested but lack the detailed structure needed for actual execution, such as steps and outcomes.

• Option C aligns more with a test plan, not a test case. A test plan outlines broader testing objectives, resources, timelines, and scope. It guides the overall testing effort but doesn't detail specific testing steps.

• Option D refers to a test oracle, which helps determine the expected results against actual outcomes. While expected results are part of a test case, the test oracle itself doesn't define a test case’s structure or procedure.

A well-designed test case serves several purposes. It helps ensure repeatability, provides traceability to requirements, and enables clear evaluation of system behavior under specified conditions. It also enhances test coverage and supports test automation when applicable.

In conclusion, Option B stands out because it comprehensively reflects the detailed framework needed for effective test execution, making it the most accurate definition of a test case.

Question 2:

Within the software development process, which activities are classified specifically under debugging rather than testing?

A. Options a and d
B. Options a and b
C. Options b and c
D. Options c and d

Correct Answer: C

Explanation:

Understanding the distinction between testing and debugging is fundamental in software development. Testing refers to the activity of executing software to uncover defects, while debugging begins only after a defect has been found, focusing on locating and resolving its root cause.

Let’s analyze the four activity options in this context:

• Option a: Designing tests to identify failures is clearly a testing activity. It involves preparing test cases and test data to evaluate whether the software behaves correctly. It does not include fixing problems, so it doesn't qualify as debugging.

• Option b: Locating the root cause of failures belongs squarely within debugging. Once a defect surfaces during testing, developers begin examining logs, code, or system behavior to determine the underlying issue. This diagnostic phase is essential in the debugging workflow.

• Option c: Fixing identified defects also constitutes debugging. After understanding the cause of the problem, developers update the code or configurations to eliminate the defect and then verify the fix. This is the corrective part of the debugging process.

• Option d: Executing tests to detect failures is a classic testing task. It involves running the application with the intention of validating its behavior against expected outcomes.

From this analysis:

• Testing includes a and d (designing and executing tests),

• Debugging includes b and c (locating and fixing defects).

Therefore, Option C is correct as it includes the two core debugging activities: identifying the cause of a failure and correcting it.

This distinction matters because while testing helps detect that something is wrong, debugging is the process of determining why and resolving it. Both are crucial in the software development life cycle, but they serve different purposes and require different skill sets.

Question 3:

What is the correct chronological sequence of events in software development when a human error leads to system failure?

A Error, fault, failure
B Fault, bug, mistake
C Mistake, failure, fault
D Failure, bug, error

Correct Answer: A

Explanation:

In software engineering, the flow of how problems arise and affect a system is best represented by the progression: error → fault → failure. This model helps identify where issues originate and how they eventually surface during software execution.

The sequence begins with a human error—an incorrect decision, misunderstanding, or action during any phase of software development (such as requirements gathering, design, or coding). This is not a technical fault yet, but a mental or procedural misstep by a person. Once this error is translated into code, it manifests as a fault (also referred to as a bug). A fault is an imperfection in the software that may cause unexpected behavior when executed. However, not every fault will result in visible problems immediately.

A failure occurs when the faulty part of the code is executed in a way that causes the system to behave abnormally—deviating from the expected results or output. Failures are observable and often reported by end users or detected during testing. Crucially, a failure only becomes apparent when the system runs under specific conditions that activate the fault.

Let’s briefly assess the other options:

• B (Fault, bug, mistake): Incorrect, as a fault and bug are nearly synonymous, and a mistake (human error) precedes both.

• C (Mistake, failure, fault): Incorrect order; a failure cannot occur before a fault exists.

• D (Failure, bug, error): Reversed entirely; a failure is the end result, not the starting point.

The correct flow—error leading to fault, then fault resulting in failure—is a fundamental principle in software testing and debugging. Understanding this sequence is critical for root cause analysis, which aims to trace observed failures back to their original human errors.

Question 4:

If a developer unintentionally inserts a fault into a software system and it is not detected during testing, what could potentially happen once the system is deployed?

A The system will definitely fail, resulting in a defect
B If the faulty code is executed, the system may fail
C It will lead to financial or reputational damage
D It indicates that contractual testing requirements were violated

Correct Answer: B

Explanation:

This question focuses on the relationship between a software fault (also called a defect or bug) and the conditions under which it might cause a failure. When a developer makes a mistake that goes undetected through testing, the software is released with an embedded fault. However, whether this fault leads to a failure depends on whether it is executed during real-world use.

In software terminology, a fault is a static imperfection in the code—an error introduced by a human that causes the software to behave incorrectly when and if that portion of the code is run. However, it is important to note that not all faults immediately cause a failure. The defect might exist in a branch of the code that is rarely used, or only activated under certain inputs or configurations.

Option B correctly highlights this relationship. The fault may reside in the system undetected, but it only causes a failure if the affected code is executed and the conditions align to expose the problem. This is why thorough testing (especially using various input combinations and usage scenarios) is critical but not foolproof.

Let’s look at the other choices:

• A is incorrect because the presence of a defect does not guarantee an immediate system failure. The system might run fine until specific conditions trigger the defective code.

• C mentions consequences like financial loss or reputation damage. While these are possible outcomes, they are not guaranteed and depend on the severity and visibility of the failure.

• D implies testing violated contractual obligations. However, even with thorough testing, some faults can still go undetected. This doesn't automatically mean that testing was non-compliant.

In summary, the most precise and technically accurate outcome is that if the defect is executed, the system may fail. Hence, B is the correct answer.

Question 5:

Which option most accurately reflects the principle known as the "pesticide paradox" in software testing?

A Regularly reviewing and updating tests is essential to continue finding new defects.
B Repeatedly running the same test cases will eventually ensure the software is free of defects.
C Most software defects tend to reside within a small subset of modules.
D Testing, like applying pesticide, is a method that removes all defects from software.

Correct Answer: A

Explanation:

The pesticide paradox in software testing is a concept that warns against the overreliance on a fixed set of test cases. Over time, repeatedly using the same tests becomes less effective because they are limited to detecting only known types of issues. Once those particular defects are addressed, continuing to execute the same tests may yield no new insights or discoveries, even though other defects may still exist. Just as pests can become immune to the same pesticide used repeatedly, defects can go undetected if new testing strategies are not introduced.

Option A correctly reflects this idea by emphasizing the need for continuous updates to test cases to maintain their effectiveness. As software evolves, so should the test suite. Regular test reviews and enhancements ensure new paths and edge cases are evaluated, which increases the likelihood of identifying new defects. Without this practice, test coverage becomes stale and incomplete.

Let’s explore why the other options are less accurate:

• B wrongly assumes that running the same tests repeatedly will lead to a defect-free system. In reality, software testing can never guarantee the absence of defects; it can only confirm the presence of those it detects.

• C references the Pareto principle in software testing (i.e., 80% of bugs reside in 20% of the code). While useful, this idea is unrelated to the pesticide paradox and does not explain the phenomenon in question.

• D misrepresents testing by comparing it to a bug removal process. Testing uncovers defects; it does not eliminate them. That’s the role of debugging and development.

In conclusion, the pesticide paradox teaches us that effective testing must be dynamic. Test cases should evolve to match changes in the application and to account for emerging risk areas. This proactive strategy keeps testing relevant and robust, making A the best explanation.

Question 6:

At what point in the software testing process is the testability of the requirements formally assessed?

A Test Execution
B Test Planning
C Test Design
D Test Analysis

Correct Answer: D

Explanation:

The test analysis phase is the part of the software testing process where the testability of requirements is critically evaluated. This stage focuses on reviewing documentation—such as functional requirements, business rules, and design specifications—to determine which aspects of the system can be tested and how. During this step, testers carefully assess whether the documented requirements are clear, complete, and measurable. Without testable requirements, meaningful and effective test cases cannot be developed.

Testability means that a requirement is stated in a way that allows it to be verified through a defined test. For instance, a vague statement like "the system should be fast" is not testable because "fast" is subjective. On the other hand, saying "the system should respond within two seconds under standard load" provides a clear, measurable benchmark that can be tested reliably.

Option D is correct because this is the phase where such evaluations take place. If testers discover that requirements are ambiguous or unverifiable, they can escalate those concerns to the project team so revisions can be made early, preventing delays in later stages.

Now let’s look at why the other options are not suitable:

• A (Test Execution) is where tests are run based on prepared scripts and test cases. If testability problems arise during execution, it's usually too late and leads to delays or ineffective testing.

• B (Test Planning) involves defining the scope, objectives, resources, and scheduling for testing. While general feasibility is considered, detailed testability assessments are not performed at this stage.

• C (Test Design) focuses on creating test cases from the conditions and scenarios derived during analysis. It assumes that the requirements have already been assessed for testability.

Ultimately, test analysis sets the foundation for the rest of the testing process. It ensures that what needs to be tested can actually be tested, making it one of the most important phases in the test lifecycle. Therefore, D is the correct answer.

Question 7:

Which option provides the greatest level of test independence during the system testing phase of a project?

A Train developers to write high-quality test cases for the testing team to use
B Assign test design and execution to an external organization
C Use the internal QA team within the company to carry out testing
D Limit communication between testers and developers to reduce bias

Correct Answer: B

Explanation:

Achieving a high degree of testing independence is critical in ensuring objective and unbiased software evaluation. Independence allows testers to assess the software without the influence of development assumptions or pressures, leading to more effective defect detection.

Among the options presented, outsourcing test design and execution to an external firm (Option B) offers the highest level of independence. This is because external testers operate completely outside the development team's structure, avoiding internal influences such as organizational bias, conflicting interests, or pressure to meet project deadlines. They rely solely on documented requirements and specifications, which leads to a more neutral and impartial assessment of the product. This structural separation is what makes outsourced testing the most independent approach.

Now let's examine the alternatives:

• A. Training developers to design tests helps improve test quality, but the test designs still originate from individuals closely involved with the code. Their intimate knowledge of the system can lead to confirmation bias, where only expected behaviors are tested, potentially missing hidden defects.

• C. Internal independent test teams are a step in the right direction, as they are separate from development. However, since they are part of the same organization, they can still be influenced by internal politics, shared priorities, or project pressures. While more independent than developers, they don’t match the neutrality of an external team.

• D. Reducing interaction between testers and developers might decrease the risk of bias, but it does not guarantee structural independence. Limiting communication may also hinder collaboration, possibly resulting in misinterpreted requirements or duplicated efforts.

Therefore, option B is correct, as outsourcing testing ensures the testers are outside the development ecosystem, promoting unbiased, impartial, and highly objective evaluations that align with the goal of achieving the maximum level of testing independence.

Question 8:

What is the most effective way to take advantage of the different ways developers and testers think during software development?

A Require testing to remain independent throughout all project phases
B Enroll all developers in ISTQB certification programs
C Keep developers and testers working in isolated teams
D Encourage collaboration between developers and testers

Correct Answer: D

Explanation:

To maximize software quality, it is essential to recognize and combine the complementary mindsets of developers and testers. Developers are typically solution-oriented, focusing on creating software that fulfills requirements and functions correctly. Testers, on the other hand, approach systems with a critical mindset, aiming to identify weaknesses, inconsistencies, or points of failure.

The most effective method of leveraging these perspectives is to foster collaboration between the two groups, as described in Option D. This collaboration allows both teams to understand each other's thought processes and incorporate quality assurance from the earliest phases of development. Developers can learn to anticipate how their code will be tested, while testers can provide feedback that may uncover issues earlier, such as design flaws or incomplete requirements.

In Agile and DevOps environments, cross-functional teams are common practice, emphasizing shared responsibility for quality. Early involvement of testers helps prevent defects, reduce rework, and improve understanding of business needs. By working together, developers and testers contribute to creating a culture of continuous improvement and open communication.

The other options fall short in this regard:

• A. Enforcing independence throughout the project can isolate testers, making it harder to identify and resolve issues early. While independent validation is important in specific phases (e.g., final acceptance), enforcing it rigidly throughout the lifecycle can reduce collaboration and slow down development.

• B. Requiring ISTQB training for all developers may help them understand testing principles, but it does not inherently create collaboration. Testing knowledge is valuable, but the real benefit lies in interpersonal interaction and mutual respect between roles.

• C. Keeping teams separate reinforces silos and reduces shared ownership. Isolated teams can result in delays, miscommunication, and missed opportunities for early defect detection.

In summary, Option D is the best answer because it encourages an environment where developers and testers can complement each other's strengths, leading to better-quality software and a more streamlined development process.

Question 9:

During which software development methodology does the need for regression testing grow steadily throughout the lifecycle?

A V-model
B Waterfall
C Scrum
D Progressive

Correct answer: C

Explanation:

Regression testing becomes increasingly vital in the Scrum model, a framework under the Agile methodology that supports incremental and iterative development. In Scrum, development occurs in fixed-length iterations called sprints, where a team continuously delivers functional increments of a product. With every sprint, new features are introduced into the existing codebase. As a result, there is an increased risk of these changes breaking previously working functionality.

To mitigate this risk, teams perform regression testing regularly, usually at the end of each sprint, to ensure that the new code does not disrupt or degrade the behavior of existing features. Over time, as more features are added and the system becomes more complex, the necessity and scope of regression testing grow. Many Scrum teams automate regression tests to maintain efficiency and ensure rapid feedback.

Looking at the other options:
A – The V-model emphasizes verification and validation processes, with corresponding test plans for each development phase. While regression testing can occur, it is not the central or progressively intensifying focus as in Scrum.
B – The Waterfall model follows a strict sequential approach, where each phase must be completed before moving to the next. Regression testing, if conducted, typically happens late in the cycle during the testing phase, and not in a repeated, cumulative manner.
D – The term Progressive is ambiguous and not a formally recognized model in the SDLC context. Without a defined framework or methodology, it doesn’t align with the structured use of regression testing.

Thus, Scrum stands out as the methodology where regression testing naturally expands and becomes more critical as the product evolves. It ensures that past features continue to work correctly while supporting frequent iterations, fast releases, and ongoing quality assurance.

Question 10:

Which pair of statements accurately describes characteristics of system testing?

A a and c
B b and d
C a and b
D c and e

Correct answer: C

Explanation:

System testing is a comprehensive testing phase conducted after integration testing and before user acceptance testing. It involves verifying that the entire integrated system meets the specified requirements outlined in the system requirement specification (SRS). This level of testing focuses on both functional and non-functional aspects, ensuring the software behaves as expected under real-world scenarios.

Let’s evaluate each statement:

a) May satisfy legal requirements – This is true. System testing may include verification against legal or regulatory requirements. For example, in industries like healthcare, finance, or aviation, software must comply with standards such as HIPAA, GDPR, or FAA regulations. These legal obligations must be verified at the system level before the software is cleared for release.

b) Can use system specifications as a test basis – This is also correct. System testing is driven by the system specifications, which detail what the application is supposed to do (functional requirements) and how it should perform (non-functional requirements). Test cases are designed based on these specifications to ensure full coverage of expected behaviors.

c) Often the responsibility of business users – This is incorrect. Business users are typically involved in user acceptance testing (UAT), which occurs after system testing. UAT focuses on validating the system against business needs, while system testing is handled by professional QA/test teams focused on technical verification.

d) Main goal is to establish confidence – This is partly true but misleading. While system testing builds confidence in the software, its primary goal is to verify that the system conforms to its specifications. Confidence-building is more aligned with UAT.

e) Should focus on the communication between systems – This describes integration testing, which tests the interactions between modules. By the time system testing occurs, these integrations are assumed to be functioning properly.

Therefore, statements a and b best reflect the goals and characteristics of system testing, making option C the correct answer.