Explanation / Rationale

a) Is not correct. This acceptance criterion describes what rules or regulations the system must adhere to (in this case, the right to be forgotten). This is an example of a rule-oriented acceptance criterion
b) Is correct. This acceptance criterion describes an example scenario that must be realizable by the system. This is an example of a scenario-oriented acceptance criterion
c) Is not correct. This sentence looks more like a line of code that implements some business rule. Acceptance criteria should be written in collaboration with business representatives, and therefore should be written in language they understand. This sentence will most likely be unintelligible to these stakeholders
d) Is not correct. This acceptance criterion describes what rules or regulations the system must adhere to and how compliance will be ensured. Therefore, this is an example of a rule-oriented acceptance criterion, not a scenario-based acceptance criterion

Explanation / Rationale

a) Is not correct. The combination (T, T, F) does not match any rule. This is an example of omission, not a contradiction
b) Is not correct. The combination (T, F, T) matches only one column, R2, so there is no contradiction
c) Is not correct. Both combinations (T, T, T) and (F, T, T) match only one column, R1, so there is no contradiction
d) Is correct. The combination (F, F, F) matches both R2 and R3, but R2 and R3 have different actions, so this shows a contradiction between R2 and R3.

Explanation / Rationale

Considering each of the listed test activities and their tasks:

A. Test analysis - To identify the features that require testing, the test basis is analyzed and defined as test conditions, which are then prioritized along with related risks. During this test analysis, defects in the test basis are typically uncovered, and the test object's testability may also be assessed. (Task 4)
B. Test design - Involves using test conditions to create test cases and other necessary testware, such as test data requirements and test charters for exploratory testing. (Task 1)
C. Test implementation - Test procedures, such as manual and automated test scripts, are created from test cases and may be assembled into test suites. Test procedures are prioritized and arranged in a test execution schedule. (Task 3)
D. Test completion - Occurs at project milestones, such as release, end of iteration or end of test level. Testware is identified and archived or handed to the appropriate teams for reuse, the test environment is shut down, and the test activities are analyzed for lessons learned and future improvements. (Task 2)

Thus:
a) Is not correct
b) Is correct. The CORRECT match is: 1B, 2D, 3C, 4A
c) Is not correct
d) Is not correct

Explanation / Rationale

Considering each of the listed tool categories:

i. Collaboration tools – facilitate communication. Communication does not include the facilitation of test execution
ii. DevOps tools - support the DevOps delivery pipeline, workflow tracking, automated build process(es) and CI/CD. The delivery pipeline and CI/CD both include the facilitation of test execution, such as component testing for CI
iii. Management tools – increase the test process efficiency by facilitating management of the SDLC, requirements, tests, defects and configuration. The management of these items does not include the facilitation of test execution
iv. Non-functional testing tools – allow the tester to perform non-functional testing that is difficult or impossible to perform manually. Non-functional testing can include both static testing and dynamic testing, including test execution
v. Test design and implementation tools – facilitate generation of test cases, test data and test procedures. The generation of this testware does not include the facilitation of test execution

Thus:
a) Is not correct
b) Is correct. Both DevOps tools (ii) and Non-functional testing tools (iv) facilitate test execution
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. The feedback is from stakeholders (e.g., business representative, end user), not from developers, so this feedback is not likely to inform managers which developers are more or less productive
b) Is not correct. Early and frequent feedback from stakeholders is not used by project managers to prioritize how they interact with the different stakeholders
c) Is correct. Obtaining feedback from stakeholders early and often in the software development process can be highly beneficial as it facilitates early communication of potential quality issues, can prevent misunderstandings about requirements, and ensures that any changes in stakeholder requirements are understood and implemented sooner
d) Is not correct. Early and frequent feedback can prevent the development of a product that does not meet stakeholder needs, and results in costly rework and missed deadlines, so, ideally there should be no delay. Also, the feedback is from stakeholders (not to them), which includes the end users, so the end users providing feedback will not aid the end users’ understanding

Explanation / Rationale

Considering each of the listed test activities and their output testware:

A. Test analysis - prioritized test conditions (4) (e.g., acceptance criteria), and defect reports for defects identified in the test basis
B. Test design - prioritized test cases, test charters, coverage items (1), test data requirements, and test environment requirements
C. Test implementation - test procedures, automated test scripts, test suites, test data, test execution schedule (3), and test environment elements such as stubs, drivers, simulators, and service virtualizations
D. Test completion - test completion report, documented lessons learned, action items for improvement, and change requests (2) (as product backlog items)

Thus:
a) Is correct. The correct match is: 1B, 2D, 3C, 4A
b) Is not correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is correct. Test-Driven Development (TDD) is a well-known example of a test-first approach to development
b) Is not correct. Coverage-Driven Development is not a correct example of a test-first approach to development
c) Is not correct. Quality-Driven Development is not a correct example of a test-first approach to development
d) Is not correct. Feature-Driven Development is not an example of a test-first approach to development, but is, instead, an agile software development methodology based around delivering features (as opposed to user stories in Scrum)

Explanation / Rationale

a) Is correct. 19 covers the “no discount” partition, 20 covers the “50% discount” partition, and 30 covers the “10% discount” partition. These three values cover all three of the valid equivalence partitions
b) Is not correct. 11 and 12 cover the “no discount” partition, while 20 covers the “50% discount” partition, so covering two of the three valid equivalence partitions
c) Is not correct. 1 covers the “no discount” partition, while 10 and 50 cover the “10% discount” partition. The “50% discount” partition is not covered, so overall two of the three valid equivalence partitions are covered
d) Is not correct. 29 and 31 cover the “no discount” partition, while 10 and 30 cover the “10% discount” partition. The “50% discount” partition is not covered, so overall two of the three valid equivalence partitions are covered

Explanation / Rationale

a) Is correct. In sequential development models, in the initial phases, testers participate in requirement reviews, test analysis, and test design. The executable code is usually created in the later phases, so dynamic testing cannot be performed early in the SDLC
b) Is not correct. Static testing can always be performed early in the SDLC
c) Is not correct. Test planning should be performed early in the SDLC before the test project begins
d) Is not correct. Acceptance testing can be performed when there is a working product. In sequential SDLC models the working product is usually delivered late in the SDLC

Explanation / Rationale

In the three-point estimation technique:

E = (optimistic + 4*most likely + pessimistic)/6

E = (2+(4*11)+14)/6 = 10

Thus:
a) Is not correct
b) Is not correct
c) Is not correct
d) Is correct

Explanation / Rationale

a) Is correct. Test design involves using test conditions to create test cases and other necessary testware, such as test data requirements and test charters for exploratory testing. Test environment requirements are also specified, including the necessary infrastructure and tools
b) Is not correct. Test execution involves executing test cases (as part of test procedures), however it does not directly cover the other testware mentioned in the question, such as test data requirements, test environment requirements and test conditions
c) Is not correct. Test analysis is used to identify the features that require testing. The test basis is analyzed and defined as test conditions, which are then prioritized along with related risks. While this activity involves working with test conditions, it does not cover the other testware mentioned in the question, such as test data requirements, test environment requirements and test cases
d) Is not correct. Test implementation includes the generation of test procedures, such as manual and automated test scripts, which are created from test cases and may be assembled into test suites. Test procedures are prioritized and arranged in a test execution schedule. Test data is created, and the test environment built, and its set up verified. While this activity involves explicitly working with test cases, and may use test data requirements and test environment requirements to create test data and the test environment, it does not cover test conditions

Explanation / Rationale

a) Is not correct. The fundamental strength of white-box test techniques is that the entire software implementation is taken into account during testing
b) Is not correct. White-box coverage measures provide an objective measure of coverage and provide the necessary information to allow additional tests to be generated to increase this coverage
c) Is not correct. White-box test techniques can be used to perform reviews (static testing)
d) Is correct. This is the weakness of the white-box test techniques. They are not able to identify the missing implementation, because they are based solely on the test object structure, not on the requirements specification

Explanation / Rationale

a) Is correct. Since 100% statement coverage is achieved, every statement, including the ones with defects, must have been executed and evaluated at least once
b) Is not correct. Coverage depends on what is tested, not on the number of test cases. For example, for code “if (x==0) y=1”, one test case (x=0) achieves 100% statement coverage, but two test cases (x=1) and (x=2) together achieve only 50% statement coverage
c) Is not correct. If there is a loop in the code there may be an infinite number of possible paths, so it is not possible to execute all the possible paths in the code
d) Is not correct. Exhaustive testing is not possible (see the seven testing principles section in the syllabus). For example, for code “input x; print x” any single test with arbitrary x achieves 100% statement coverage, but covers one input value

Explanation / Rationale

a) Is not correct. This sequence of five events covers 4 different valid transitions (both “NotAvailable” events correspond to the same transition between S1 and S3). This test case covers 4 out of 7 valid transitions
b) Is correct. This sequence of five events covers 5 different transitions (the first “Available” event corresponds to a transition between S1 and S2, and the second “Available” event corresponds to a transition between S3 and S2, so two different transitions are covered). This test case covers 5 out of 7 valid transitions and achieves the highest valid transitions coverage
c) Is not correct. This sequence of five events covers 3 different transitions (both “Available” events correspond to the same transition from S1 to S2; both “ChangeRoom” events correspond to the same transition from S2 to S1). This test case covers 3 out of 7 valid transitions
d) Is not correct. This sequence of five events does not represent a feasible test case, because after “Cancel” the system ends up in the End state and no further valid transitions can be executed

Explanation / Rationale

There are three equivalence partitions: {…, –2, –1}, {0, 1, 2}, {3, 4, …}.
For 2-value BVA all the boundary values for all the equivalence partitions must be covered.
The boundary values are –1 (for the “temperature too low” partition), 0, 2 (for the “temperature OK” partition) and 3 (for the “temperature too high” partition).

Thus:
a) Is not correct
b) Is not correct
c) Is correct. The correct option is: –1, 0, 2, 3
d) Is not correct

Explanation / Rationale

a) Is not correct. Finding and fixing defects in the test object is not a typical test objective as although identifying defects is an objective of testing, fixing defects is not a testing activity
b) Is not correct. Maintaining effective communications with developers is not a typical test objective as although it is useful in achieving other objectives of testing, such as providing stakeholders with information that enables them to make informed decisions, it is not a primary reason for performing testing
c) Is not correct. Validating that legal requirements have been met is not a typical test objective because validation is concerned with checking whether the system meets users’ and other stakeholders’ needs in its operational environment. Checking that legal requirements have been met is a form of verification
d) Is correct. Building confidence in the quality of the test object is achieved by executing tests that pass

Explanation / Rationale

a) Is not correct. Strong communication skills, active listening, and teamwork abilities enable a tester to interact effectively with all stakeholders, however a deep knowledge of a variety of computer games that allowed them to get on well with one developer is not an example of a generic skill useful to testers
b) Is correct. Domain knowledge that can be used to understand and communicate with end-users and business representatives is one of the generic skills required by testers. A tester with experience as a pilot would make them better able to appreciate the acceptance criteria for the helicopter control system
c) Is not correct. Although programming skills could be considered as technical knowledge which can increase efficiency when utilizing some test tools, it is unlikely that these skills would improve their communication with business analysts
d) Is not correct. Although thoroughness, attention to detail, curiosity, and a methodical approach to identifying hard-to-find defects are all useful generic skills for testers, it is doubtful they would be generating test cases prior to starting exploratory testing. This is because one of the main tenets of exploratory testing is that the test cases are generated during the testing, not scripted in advance

Explanation / Rationale

a) Is not correct. Tracking test progress and identifying areas that require further attention is an example of supporting the ongoing control of testing. This is one of the purposes of test reports
b) Is not correct. Providing information on the tests executed, their results, and any issues or defects found is an example of summarizing the test activities performed at a given test level. This is one of the purposes of test reports
c) Is correct. Providing information about defects is the purpose of a defect report, not a test report
d) Is not correct. Providing information on testing planned for the next period is one of the purposes of test reports

Explanation / Rationale

a) Is not correct. Impediments to testing can be high level and business-related, so this is an important piece of information for business stakeholders
b) Is correct. Branch testing is a technical metric used by developers and technical testers. This information is of no interest to business representatives
c) Is not correct. Test progress is project related, so it may be useful for business representatives
d) Is not correct. Risks impact product quality, so it may be useful for business representatives

Explanation / Rationale

a) Is not correct. The rule-oriented format includes formats like bullet point verification lists or tabulated forms of input-output mappings, explicitly showing the rules to be followed. Given/When/Then is a scenario-oriented format because it describes a scenario to be verified
b) Is correct. This is a Given/When/Then format, which is scenario-oriented
c) Is not correct. There no "product-oriented" format of acceptance criteria
d) Is not correct. There is no "process-oriented" format of acceptance criteria

Explanation / Rationale

The ‘exhaustive testing is impossible’ principle is concerned with the fact that it is not feasible to test every possible variation of test inputs in all different circumstances, except in trivial cases. Instead, testing utilizes test techniques, test case prioritization, and risk-based testing to sample from the set of possibilities and focus testing efforts.
a) Is not correct. The principle states that it is not feasible to test everything except in trivial cases. Testing everything would require testing every possible variation of test inputs in all different circumstances, which is generally infeasible as there will be a practically infinite number. Testing every possible specified output will not address this problem as the relationship between inputs and specified outputs can be different for each test object. Sometimes there may be a practically infinite number of possible specified outputs (e.g., when there are several variables representing real numbers), whereas at other times there may be just two specified outputs, such as with a single variable that can be either true or false
b) Is not correct. The principle states that it is not feasible to test every possible variation of test inputs in all different circumstances. This is because for non-trivial systems there is a practically infinite number. Therefore, in practice, documenting all possible test input variations would be impractical as it would take an infinite length of time
c) Is not correct. Starting testing as early as possible with reviews and other static testing approaches will not address the problem of there being too many possible test cases. The ‘early testing saves time and money’ principle is concerned with fixing defects early on to prevent the occurrence of subsequent defects in derived work products, thereby reducing costs and the likelihood of failures
d) Is correct. The use of equivalence partitioning and boundary value analysis to generate test cases is one way to address the principle as these test techniques provide a systematic way to derive a finite subset of all possible test cases

Explanation / Rationale

a) Is not correct. The miscalculation of bonuses is a failure by the system, not a defect
b) Is not correct. The system not suitably supporting disabled users is a failure which eventually results in a fine, but the fine itself is not a failure (it appears to be the correct functioning of the regulatory system)
c) Is correct. The error is made by the programmer and this mistake is caused by them working under severe time pressure, which is the root cause of the subsequent defect
d) Is not correct. The poor design of the user interface, which does not suitably address disabled users, is a design defect caused by the designer error. Thus the design of the user interface includes a design defect not a designer error

Explanation / Rationale

a) Is not correct. One of the purposes of retrospectives is to identify potential process improvements, which, if put into practice, should result in the quality of future outputs of the development process (test objects) being higher. So, this is likely to occur as a result of a retrospective
b) Is not correct. A benefit of retrospectives for testing includes increased test efficiency through process improvements. So, this is likely to occur as a result of a retrospective
c) Is correct. Participants at retrospectives typically include testers, developers, architects, product owners, and business analysts, but end users are rarely invited or attend these meetings – and they are also unlikely to receive any reports from these meetings. So, it is very unlikely that they will learn and understand more about the development and test processes through retrospectives
d) Is not correct. A benefit of retrospectives for testing includes improved quality of testware (including automated test scripts) through joint reviews with developers. So, this is likely to occur as a result of a retrospective

Explanation / Rationale

a) Is not correct. A lack of usability provided through the user interface can be detected through a review using a suitable checklist, but the lack of usability can also be identified by getting several typical users to dynamically test the user interface and provide feedback on its usability
b) Is correct. A code review can detect code that cannot be reached by any path, however dynamic tests can only exercise reachable code and cannot determine that code cannot be reached without running every possible combination of inputs and input states, which is impractical for real code
c) Is not correct. Poor response times for most of the expected users are difficult to determine without executing the code (i.e., by static testing), so in this situation dynamic testing could find a defect, but static testing is unlikely to find it
d) Is not correct. A review of the code by someone who is aware of the required features could detect that the required features had not been implemented in the code, and dynamic testing could also be used to determine that these required features had not been implemented

Explanation / Rationale

Considering each of the listed example defects:

i. Two different parts of the design specification disagree due to the complexity of the design – this is an example of a specification defect, which includes inconsistencies, ambiguities, contradictions, omissions, inaccuracies, and duplications, which can most easily be found by static testing
ii. A response time is too long and so makes users lose patience – this is an example of a response time defect, which can only be detected in practice by executing the program and measuring the response time, which can most easily be found by dynamic testing
iii. A path in the code cannot be reached during execution - this is an example of a coding defect, which includes variables with undefined values, undeclared variables, duplicated or unreachable code, and excessive code complexity, which can most easily be found by static testing
iv. A variable is declared but never subsequently used in the program - this is an example of a coding defect, which includes variables with undefined values, undeclared variables, duplicated or unreachable code, and excessive code complexity, which can most easily be found by static testing
v. The amount of memory needed by the program to generate a report is too high – this is an example of a performance defect, which can only be detected in practice by executing the program and measuring the memory used, which can most easily be found by dynamic testing

Thus:
a) Is not correct
b) Is not correct
c) Is not correct
d) Is correct. The correct match for static testing is i, iii, and iv

Explanation / Rationale

a) Is not correct. Practices involved in shift-left testing are aimed at implementing more testing activities in the early phases of the development life cycle, portraying the SDLC as moving from left to right. There is no such thing as the left-hand side of the test process
b) Is correct. Shift-left emphasizes the importance of starting testing earlier in the software development lifecycle (SDLC). Implementing shift-left testing necessitates additional training, and increased effort and costs during the early stages of the SDLC, nevertheless, overall savings should be higher
c) Is not correct. Although automated component tests and component integration tests for regression testing are generally valuable, the creation of these tests is normally the responsibility of the developers, and if a continuous integration/continuous delivery (CI/CD) approach is followed, then these tests will have been submitted with the code. In some situations the tester may automate tests for regression testing, and sometimes even for component tests and component integration tests, however this is not part of a ‘shift-left’ approach which moves testing earlier in the SDLC
d) Is not correct. Training testers to perform tasks early in the SDLC would support a shift-left approach by emphasizing the importance of starting testing earlier in the SDLC. However, automating more test activities to be performed later in the SDLC is not part of a ‘shift-left’ approach

Explanation / Rationale

a) Is not correct. It is more often used in behavior-driven development (BDD)
b) Is not correct. It is the description of test-driven development (TDD)
c) Is correct. In acceptance test-driven development (ATDD) tests are written from acceptance criteria as part of the design process
d) Is not correct. It is used in BDD

Explanation / Rationale

a) Is correct. It is important that testers are involved from the beginning of the software development lifecycle (SDLC). It will increase understanding of design decisions and will detect defects early.
b) Is not correct. Both developers and testers will have more understanding of each other's work products and how to test the code
c) Is not correct. End users will not help the testers in increasing the quality of defect reports; also, users usually do not participate in low-level testing levels like integration testing
d) Is not correct. Being certified does not automatically mean that the tester will be better in test design

Explanation / Rationale

a) Is not correct. In the whole-team approach, testers play a vital role by sharing their testing expertise with the team and guiding product development. They collaborate with other team members to achieve the desired quality levels and work with business representatives to create acceptance tests. Testers also partner with developers to determine the optimal test strategy and automation approaches
b) Is correct. By leveraging the diverse skill sets of each team member most effectively, the whole-team approach fosters superior team dynamics, promotes robust communication and collaboration, and generates a synergistic effect that benefits the entire project
c) Is not correct. The whole-team approach allows any team member with the requisite skills and knowledge to undertake any task, thus specialist team members are not an advantage of this approach
d) Is not correct. There is no specific guidance on the optimum size of teams using the whole-team approach, and there is no suggestion that larger teams are better

Explanation / Rationale

a) Is not correct. Although it is true that the tester can implement and execute detailed test cases based on the checklist, it does not explain how this would result in increased coverage
b) Is not correct. Checklist items should not be automated. But even if they are, the automated test scripts always execute the tests in the same way, which usually does not result in increased coverage
c) Is not correct. It is true that each checklist item should be tested separately and independently. But this impacts the test execution order and does not impact the achieved coverage, and so does not result in increased coverage
d) Is correct. If the checklists are high-level, some variability in the actual testing is likely to occur, resulting in potentially greater coverage but less repeatability. If two testers follow a checklist of high-level items, each of them may use different test data, test steps, etc. This way, one tester will probably cover some areas not covered by the other tester and this will result in increased coverage

Explanation / Rationale

a) Is not correct. The root cause is the distraction that the programmer experienced while programming
b) Is not correct. Accepting invalid inputs is a failure
c) Is not correct. The error is the mistaken thinking that resulted in putting the defect in the code
d) Is correct. The problem in the code is a defect

Explanation / Rationale

a) Is correct. Product quality metrics measure quality characteristics. Mean time to failure measures maturity, so it is a product quality metric
b) Is not correct. This is an example of a defect metric, not a product quality metric
c) Is not correct. This is an example of a coverage metric, not a product quality metric
d) Is not correct. This is an example of a defect metric, not a product quality metric

Explanation / Rationale

a) Is not correct. In all types of reviews there is more than one role, even in informal ones
b) Is correct. There are several activities during the formal review process
c) Is not correct. Documentation to be reviewed should be distributed as early as possible
d) Is not correct. Defects found during the review should be reported

Explanation / Rationale

Consider:

i. It is a Project risk
ii. It is a Product risk
iii. It is a Product risk
iv. It is a Project risk
v. It is a Product risk

Thus:
a) Is correct
b) Is not correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is correct. Obtaining feedback from stakeholders early and often in the software development process can be highly beneficial. It facilitates early communication of potential quality issues, can prevent misunderstandings about requirements, and ensures that any changes in stakeholder requirements are understood and implemented sooner
b) Is not correct. The feedback is from stakeholders, and them providing feedback is unlikely to improve their understanding of their own user requirements
c) Is not correct. Obtaining feedback from stakeholders early and often in the software development process can be highly beneficial. It facilitates early communication of potential quality issues, can prevent misunderstandings about requirements, and ensures that any changes in stakeholder requirements are understood and implemented sooner. However, because changes in requirements can be understood and implemented sooner, it does not mean that unlimited changes to requirements are encouraged
d) Is not correct. The feedback is from stakeholders and does not cover communication to them. Communications to end users could include them being told about which requirements will not be implemented prior to release, but ideally this should not happen at all

Explanation / Rationale

a) Is not correct. We want to check that Special users have the rights of Regular users, so we need to test access rights for a Special user, not for a Regular user
b) Is not correct. We want to check that Special users have the rights of Regular users, so we need to test access rights for a Special user, not for a Regular user
c) Is not correct. There is no floor 5 described in the acceptance criteria. The test cases should not extend the scope of the user story. But even if we would like to perform negative testing, this test is not directly related to AC3
d) Is correct. This way we can check if a Special user can access floors which are accessible to a Regular user

Explanation / Rationale

Some defect types that can only be detected by static testing, such as unreachable code, design patterns not implemented as desired and defects in non-executable work products. Some defect types that can be found by both static testing and dynamic testing, such as a programming defect that can be observed by a reviewer in a code review and which causes an observable failure during dynamic testing. And some defect types that can only be detected by dynamic testing, such as performance issues or memory issues that can only be observed when executing the code or system.

Thus:
a) Is not correct
b) Is not correct
c) Is correct
d) Is not correct

Explanation / Rationale

Test TC 001 must come first, followed by TC 002, to satisfy dependencies. Afterwards, TC 003 to satisfy priority and then TC 004, followed by TC 005.
Thus:
a) Is correct
b) Is not correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. Component Test-Driven Development is not a correct example of a test-first approach to development
b) Is not correct. Integration Test-Driven Development is not a correct example of a test-first approach to development
c) Is not correct. System Test-Driven Development is not a correct example of a test-first approach to development
d) Is correct. Acceptance Test-Driven Development (ATDD) is a well-known example of a test-first approach to development

Explanation / Rationale

a) Is correct. The primary benefit of independence in testing is that testers are more likely to identify different types of failures and defects compared to developers, due to their varied backgrounds, technical viewpoints, and potential biases, including cognitive bias. However, the main disadvantage of independence in testing is that testers may become isolated from the development team, leading to communication problems, a lack of collaboration, and potentially an adversarial relationship, with testers being blamed for delays and bottlenecks in the release process
b) Is not correct. A developer’s familiarity with the code does not mean that they rarely find defects in it, instead this familiarity means they can efficiently find many defects in their own code. And, rather than developers and testers having a shared background, developers having a different background to testers is normally cited as the reason that testers and developers find different kinds of defects
c) Is not correct. Testing can be conducted at different levels of independence, ranging from no independence for the author to very high independence for testers from outside the organization. In most projects, multiple levels of independence are utilized, with developers performing component and component integration testing, the test team performing system and system integration testing, and business representatives performing acceptance testing. So, testers can be in the developer’s team and do not need to come from outside the organization. Knowledge of the application domain will change from case-to-case and is not dependent on the level of independence
d) Is not correct. Testing can be conducted at different levels of independence, ranging from no independence for the author to very high independence for testers from outside the organization, with testers from outside the developer’s team generally more independent than testers from within the team. However, there is more reason to believe that testers from outside the team are likely to be more isolated from the developers and so are more likely to be blamed for delays in product release