แบบฝึกหัด ISTQB Certified Tester Foundation Level (CTFL) Part 1

ISTQB Certified Tester Foundation Level Exercises

Content

1. Keywords
2. FL-1.x
3. FL-1.1.1 Identify typical objectives of testing (K1)
4. FL-1.1.2 Differentiate testing from debugging (K2)
5. FL-1.2.3 Distinguish between error, defect, and failure (K2)
6. FL-1.2.4 Distinguish between the root cause of a defect and its effects (K2)
7. FL-1.3.1 Explain the seven testing principles (K2)

✍Keywords

Question1 Which of the following provides the BEST description of a test case? A document specifying a sequence of actions for the execution of a test. Also known as test script or manual test script. A set of input values and expected results, with execution pre-conditions and execution post -conditions, developed for a particular test condition. An attribute of a system specified by requirements documentation (for example reliability, usability or design constraints) that is executed in a test. An item or event of a system that could be verified by one or more test conditions, e.g., a function, transaction, feature, quality attribute, or structural element.

Solution  Is not correct: Based on definition of a test procedure specification. Correct: Based on definition from Glossary. Is not correct: Based on Glossary definition of feature. Is not correct: Based on definition of test condition but replaced the term test case with test condition.

Question2 Which of the following provides the BEST description of exploratory testing? A testing practice in which an in-depth investigation of the background of the test object is used to identify potential weaknesses that are examined by test cases. An approach to testing whereby the testers dynamically design and execute tests based on their knowledge, exploration of the test item and the results of previous tests. An approach to test design in which test activities are planned as uninterrupted sessions of test analysis and design, often used in conjunction with checklist-based testing. Testing based on the tester's experience, knowledge and intuition.

Solution2  Is not correct: Exploratory testing is often carried out when timescales are short, so making in-depth investigations of the background of the test object is unlikely. Correct: Glossary definition. Is not correct: Based on the Glossary definition of session-based testing, but with test execution replaced by test analysis. Is not correct: Glossary definition of experience-based testing.

✍FL-1.x

Question3 Which one of the following answers describes a test condition? An attribute of a component or system specified or implied by requirements documentation. An aspect of the test basis that is relevant to achieve specific test objectives. The degree to which a software product provides functions which meet stated and implied needs when the software is used under specified conditions. The percentage of all single condition outcomes that independently affect a decision outcome that have been exercised by a test suite.

Solution3  Is not correct: Definition of feature according to glossary. Is correct: From glossary. Is not correct: Definition of functionality suitability according to glossary. Is not correct: Definition of modified condition decision coverage according to glossary.

✍FL-1.1.1 Identify typical objectives of testing (K1)

Question4 Which of the following statements is a valid objective for testing? The test should start as late as possible so that development had enough time to create a good product. To find as many failures as possible so that defects can be identified and corrected. To prove that all possible defects are identified. To prove that any remaining defects will not cause any failures.

Solution4  Is not correct: Contradiction to principle 3: “Early testing saves time and money”. Is correct: This is one objective of testing (syllabus chapter 1.1.1). Is not correct: Principle #2 states that exhaustive testing is impossible, so one can never prove that all defects were identified (syllabus chapter 1.3). Is not correct: To make an assessment whether a defect will cause a failure or not, one has to detect the defect first. Saying that no remaining defect will cause a failure implicitly means that all defects were found. This again contradicts principle #2. (syllabus chapter 1.3).

Question5 Which of the following is a major objective of testing? To prevent defects. To validate the project plan works as required. To gain confidence in the development team. To make release decisions for the system under test.

Solution5  Correct: One of the major objectives of testing from the syllabus (1.1.1). Is not correct: Validation of the project plan would be a project management activity. Is not correct: Gaining confidence in the development team would be achieved through observation and experience. Is not correct: One of the main objectives during acceptance testing may be to give information to stakeholders about the risk of releasing the system at a given time – so testing provides information for stakeholders to make decisions, it does not provide the release decision.

✍FL-1.1.2 Differentiate testing from debugging (K2)

Question6 Which of the following statements correctly describes the difference between testing and debugging? Testing identifies the source of defects; debugging analyzes the defects and proposes prevention activities. Dynamic testing shows failures caused by defects; debugging finds, analyzes, and removes the causes of failures in the software. Testing removes defects; debugging identifies the causes of failures. Dynamic testing prevents the causes of failures; debugging removes the failures.

Solution6  Is not correct: Testing does not identify the source of defects, debugging identifies the defects (syllabus chapter 1.1.2). Is correct: Dynamic testing can show failures that are caused by defects in the software. Debugging eliminates the defects, which are the source of failures, not the root cause of the defects (syllabus 1.1.2). Is not correct: Testing does not remove faults, but debugging remove defects that cause the faults (syllabus chapter 1.1.2).  Is not correct: Dynamic testing does not directly prevent the causes of failures (defects), but detects the presence of defects (syllabus chapter 1.3, 1. principle).

✍FL-1.2.3 Distinguish between error, defect, and failure (K2)

Question7 Which one of the statements below describes the most common situation for a failure discovered during testing or in production? The product crashed when the user selected an option in a dialog box. The wrong version of a compiled source code file was included in the build. The computation algorithm used the wrong input variables. The developer misinterpreted the requirement for the algorithm.

Solution7  Is correct: A crash is clearly noticeable by the user (syllabus chapter 1.2.3). Is not correct: this is a defect, not a failure, since there is something wrong in the code. It may not result in a visible or noticeable failure, for example if the changes in the source code file are only in comments (syllabus chapter 1.2.3). Is not correct: The use of wrong input variables may not result in a visible or noticeable failure, for example if nobody uses this particular algorithm; or if the wrong input variable has a similar value to the correct input variable; or if the FALSE result of the algorithm is not used (syllabus chapter 1.2.3). Is not correct: This type of fault will not necessarily lead to a failure; for example, if no one uses this special algorithm (syllabus chapter 1.2.3).

Question8 Which of the following is an example of a failure in a car cruise control system? The developer of the system forgot to rename variables after a cut-and-paste operation. Unnecessary code that sounds an alarm when reversing was included in the system. The system stops maintaining a set speed when the radio volume is increased or decreased. The design specification for the system wrongly states speeds in km/h.

Solution8  Is not correct: This is an example of a mistake made by the developer. Is not correct: This is an example of a defect (something wrong in the code that may cause a failure). Correct: This is a deviation from the expected functionality - a cruise control system should not be affected by the radio. Is not correct: This is an example of a defect (something wrong in a specification that may cause a failure if subsequently implemented)

✍FL-1.2.4 Distinguish between the root cause of a defect and its effects (K2)

Question9 Which of the following is a defect rather than a root cause in a fitness tracker? Because he was unfamiliar with the domain of fitness training, the author of the requirements wrongly assumed that users wanted heartbeat in beats per hour. The tester of the smartphone interface had not been trained in state transition testing, so missed a major defect. An incorrect configuration variable implemented for the GPS function could cause location problems during daylight saving times. Because she had never worked on wearable devices before, the designer of the user interface misunderstood the effects of reflected sunlight.

Solution9  Is not correct: The lack of familiarity of the requirements author with the fitness domain is a root cause. Is not correct: The lack of training of the tester in state transition testing was one of the root causes of the defect ( the developer presumably created the defect, as well). Correct: The incorrect configuration data represents faulty software in the fitness tracker (a defect), that may cause failures. Is not correct: The lack of experience in designing user interfaces for wearable devices is a typical example of a root cause of a defect.

✍FL-1.3.1 Explain the seven testing principles (K2)

Question10 Mr. Test has been testing software applications on mobile devices for a period of 5 years. He has a wealth of experience in testing mobile applications and achieves better results in a shorter time than others. Over several months Mr. Test did not modify the existing automated test cases and did not create any new test cases. This leads to fewer and fewer defects being found by executing the tests. What principle of testing did Mr. Test not observe? Testing depends on the environment. Exhaustive testing is not possible. Repeating of tests will not find new defects. Defects cluster together.

Solution10  Is not correct: Testing is context dependent, regardless of it being manual or automated (syllabus chapter 1.3, 6. principle), but does not result in detecting a decreasing number of faults as described above. Is not correct: Exhaustive testing is impossible, regardless of the amount of effort put into testing (syllabus chapter 1.3, 2. principle). Is correct: Syllabus 1.3: principle #5 says “If the same tests are repeated over and over again, eventually these tests no longer find any new defects. To detect new defects, existing tests and test data may need changing, and new tests may need to be written.” Automated regression testing of the same test cases will not bring new findings. Is not correct:”Defects cluster together” (syllabus chapter 1.3.4, 4. principle). A small number of modules usually contain most of the defects, but this does not mean that fewer and fewer defects will be found.

Question11 As a result of risk analysis, more testing is being directed to those areas of the system under test where initial testing found more defects than average. Which of the following testing principles is being applied? Beware of the pesticide paradox. Testing is context dependent. Absence-of-errors is a fallacy. Defects cluster together.

Solution11  Is not correct: ‘Beware of the pesticide paradox’ is concerned with re-running the same tests and their fault-finding effectiveness decreasing. Is not correct: This testing principle is concerned with performing testing differently based on the context (e.g. games vs safety-critical). Is not correct: This testing principle is concerned with the difference between a tested and fixed system and a validated system. No ‘errors’ does not mean the system is fit for use. Correct: If clusters of defects are identified (areas of the system containing more defects than average), then testing effort should be focused on these areas.