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ISTQB CTAL-TTA study materials
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ISTQB CTAL-TTA practice questions

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Question 1Risk-based testing

In risk-based testing at the advanced technical level, which product risk factor most directly justifies increasing the depth of white-box coverage for a payment module?

  1. The module's high cyclomatic complexity combined with its financial impact if defective Correct answer.
  2. The module being scheduled for delivery in the final release increment
  3. The module having few automated unit tests at present
  4. The module being written in a language the team adopted recently

Explanation

Product risk combines likelihood and impact. High complexity raises defect likelihood, and financial impact raises consequence, so together they justify deeper structural coverage. The other factors describe process or scheduling circumstances rather than the risk profile of the product itself.

Question 2Risk-based testing

What is the primary purpose of performing a risk analysis before designing test conditions in a risk-based approach?

  1. To identify and prioritise risks so testing effort can be allocated proportionally Correct answer.
  2. To confirm that all requirements have been formally approved
  3. To record which developers introduced the most defects previously
  4. To estimate the total number of test cases the team must write

Explanation

Risk analysis identifies risks and assigns likelihood and impact so that test effort can be directed where it matters most. It is an input to planning and design, not a mechanism for counting test cases or apportioning blame.

Question 3Risk-based testing

A team uses risk levels to decide test depth. Which combination of likelihood and impact should receive the most rigorous test approach?

  1. Low likelihood, high impact
  2. High likelihood, high impact Correct answer.
  3. High likelihood, low impact
  4. Low likelihood, low impact

Explanation

Risk exposure is greatest when both likelihood of failure and impact of failure are high, so the most rigorous approach is warranted there. Combinations with one low dimension produce lower exposure and can accept lighter coverage.

Question 4Risk-based testing

Which statement best describes how risk-based testing should influence regression test selection after a change?

  1. Regression tests should be chosen only by the order in which they were automated
  2. Regression tests should be limited to the modules the developer edited
  3. All regression tests should always run regardless of the change to guarantee safety
  4. Regression tests should be selected based on the risk of the areas affected by the change Correct answer.

Explanation

Risk-based regression selection targets the areas where a change creates the greatest chance and consequence of failure, including indirectly affected areas. Running everything ignores cost, while restricting to edited modules misses ripple effects.

Question 5Risk-based testing

During risk identification, which technique is most appropriate for surfacing risks that stakeholders may not volunteer individually?

  1. A structured brainstorming session with cross-functional participants Correct answer.
  2. A single interview with the project manager only
  3. Counting the number of open defect reports
  4. Reading the source code without any stakeholder involvement

Explanation

Structured brainstorming with diverse participants draws out risks that individuals might overlook or not raise alone. Single-source input and purely technical review narrow the perspective and miss organisational and usage risks.

Question 6Risk-based testing

A risk register lists a risk as high, but the test manager notes the risk owner is unknown. What is the most appropriate action from a risk-based testing perspective?

  1. Ignore the risk until an owner is assigned by someone else
  2. Assign an owner and mitigation actions so the risk can be tracked and addressed Correct answer.
  3. Lower the risk rating so it no longer requires an owner
  4. Remove the risk from the register to keep it consistent

Explanation

Each significant risk needs an owner and mitigation so it can be monitored and acted upon; otherwise the rating has no operational effect. Ignoring, downgrading, or deleting the risk defeats the purpose of the register.

Question 7Risk-based testing

In risk-based testing, what distinguishes a product risk from a project risk?

  1. Product risks affect only users; project risks affect only the test team
  2. Product risks are identified by testers; project risks are identified by developers
  3. Product risks concern the delivered software's potential failures; project risks concern the project's ability to deliver Correct answer.
  4. Product risks are always technical; project risks are always financial

Explanation

Product risks relate to the quality and potential failure of the software product, while project risks relate to management and delivery factors such as schedule, staffing, and budget. The distinction is about what is at risk, not who identifies it.

Question 8Risk-based testing

Which metric best supports ongoing risk-based test monitoring during execution?

  1. The total lines of code in the system
  2. The percentage of high-risk test conditions that have passed Correct answer.
  3. The number of test cases written per developer
  4. The number of meetings held by the test team

Explanation

Monitoring coverage and pass status of high-risk test conditions shows whether the most important risks are being reduced. The other metrics measure activity volume rather than risk mitigation.

Question 9Risk-based testing

How should risk levels influence the choice between exhaustive and sample-based test techniques?

  1. Lower-risk items always require exhaustive techniques
  2. Technique selection depends only on the tester's preference
  3. Risk level has no bearing on technique selection
  4. Higher-risk items justify more exhaustive techniques; lower-risk items can use sampling Correct answer.

Explanation

Risk-based testing allocates rigour in proportion to risk, so high-risk items warrant more thorough or exhaustive techniques while low-risk items can be sampled. This is a core principle of proportionate effort.

Question 10Risk-based testing

A team must decide test exit criteria for a release under risk-based testing. Which criterion is most aligned with the approach?

  1. No open defects remain in any module
  2. All high-risk areas have met their agreed coverage and residual risk is accepted Correct answer.
  3. The test environment has been decommissioned
  4. All planned test cases have been executed at least once

Explanation

Risk-based exit criteria focus on whether the highest risks have been sufficiently addressed and whether residual risk is acceptable to stakeholders. Executing all tests or demanding zero defects ignores risk proportionality.

Question 11Risk-based testing

Which statement about the relationship between risk analysis and test design is correct?

  1. Test design must be completed before any risk analysis begins
  2. Risk analysis output guides which test conditions receive deeper design effort Correct answer.
  3. Risk analysis replaces the need for test design techniques
  4. Risk analysis and test design are unrelated activities

Explanation

Risk analysis informs test design by indicating where deeper or more thorough design effort should be invested. It complements rather than replaces design techniques, and the activities are iterative rather than strictly ordered.

Question 12Risk-based testing

When estimating test effort using a risk-based approach, what is the most defensible basis for allocating effort across features?

  1. Effort proportional to the assessed risk level of each feature Correct answer.
  2. Equal effort for every feature to avoid bias
  3. Effort proportional to the age of the code in each feature
  4. Effort proportional to the number of screens in each feature

Explanation

Risk-based estimation distributes effort in proportion to assessed risk, so higher-risk features receive more testing. Equal allocation ignores risk differences, and screen counts or code age are weak proxies.

Question 13Risk-based testing

Which of the following is a typical source of information for identifying product risks during risk analysis?

  1. The version control branching strategy
  2. The team's holiday schedule
  3. The office seating plan
  4. Historical defect data and customer complaint records Correct answer.

Explanation

Historical defect data and customer complaints reveal where failures have occurred and what matters to users, making them strong inputs for product risk identification. Schedule, seating, and branching are project or process matters.

Question 14Risk-based testing

A tester finds that a risk rated medium has a very high technical uncertainty because the underlying algorithm is unproven. What is the most appropriate response?

  1. Keep the rating unchanged because impact is only medium
  2. Ignore the uncertainty because the algorithm is internal
  3. Defer all testing of the algorithm to the next project
  4. Raise the risk level to reflect the uncertainty and increase investigative testing Correct answer.

Explanation

Technical uncertainty increases the likelihood of defects, so the risk level should reflect it and investigative testing should increase. Ignoring uncertainty or deferring testing leaves the risk unmanaged.

Question 15Risk-based testing

In a risk-based test strategy, what role does the risk of a requirement play in prioritising test cases?

  1. It determines the order and depth in which test cases for that requirement are designed and run Correct answer.
  2. It determines the licence cost of the test tool
  3. It determines which developer writes the test cases
  4. It determines the language used to write the test cases

Explanation

Requirement risk drives prioritisation, so test cases for higher-risk requirements are designed and executed earlier and more thoroughly. The other options describe administrative or tooling matters unrelated to prioritisation.

Question 16Risk-based testing

Which statement best captures how risk-based testing handles the trade-off between thoroughness and available time?

  1. It guarantees complete coverage regardless of time
  2. It concentrates effort on the highest risks first so that time pressure degrades lower-risk coverage Correct answer.
  3. It removes all testing when time is short
  4. It spreads effort evenly so every area gets the same time

Explanation

Risk-based testing front-loads effort on the highest risks so that, if time runs short, the least important coverage is what gets reduced. It cannot guarantee complete coverage and does not abandon testing.

Question 17Risk-based testing

What is the main benefit of maintaining a risk register that is reviewed at each test cycle?

  1. It removes the need for regression testing
  2. It replaces the need for a test plan
  3. It guarantees that no defects will reach production
  4. It keeps risk ratings current so test effort tracks changing exposure Correct answer.

Explanation

Regular review keeps risk ratings current as information changes, so test effort continues to track real exposure. A register informs planning but does not replace the plan or eliminate defects or regression testing.

Question 18Risk-based testing

A project has a fixed budget and a large set of features. Which approach best applies risk-based testing to decide what to test first?

  1. Test the features the developers finished most recently first
  2. Test the features with the most lines of code first
  3. Rank features by risk exposure and test the highest-ranked first Correct answer.
  4. Test features in the order they appear in the requirements document

Explanation

Ranking by risk exposure directs limited budget to the areas of greatest likelihood and impact. Document order, completion order, and code size are not risk measures.

Question 19Risk-based testing

Which of the following best describes residual risk in the context of risk-based testing?

  1. The risk of hiring new testers
  2. The risk introduced by the test tool itself
  3. The risk that the risk register will be lost
  4. The risk that remains after planned test activities have been completed Correct answer.

Explanation

Residual risk is what remains once the planned mitigation, including testing, has been performed, and stakeholders must decide whether to accept it. Tool, staffing, and record-keeping concerns are separate project risks.

Question 20Risk-based testing

During risk analysis, two stakeholders rate the same risk very differently. What is the most appropriate way to proceed?

  1. Adopt the lower rating to avoid over-testing
  2. Discard the risk because opinions differ
  3. Adopt the higher rating without discussion
  4. Discuss the discrepancy to reach a shared, evidence-based rating Correct answer.

Explanation

Differing ratings signal a need to share evidence and reach a common understanding of likelihood and impact. Simply choosing the lower or higher value, or discarding the risk, bypasses the analysis that makes risk-based testing meaningful.

Question 21Risk-based testing

Which situation most clearly indicates that risk-based testing should trigger additional exploratory testing rather than more scripted tests?

  1. A low-risk area has a stable, well-documented interface
  2. A high-risk area has unclear requirements and emergent behaviour Correct answer.
  3. A high-risk area has a complete, stable specification
  4. A low-risk area has many automated regression tests

Explanation

High risk combined with unclear requirements and emergent behaviour favours exploratory testing, which adapts as understanding grows. Stable specifications and low-risk areas are better served by scripted or existing automated tests.

Question 22Risk-based testing

What does a risk-based approach recommend regarding the testing of non-functional characteristics such as performance and security?

  1. They should be tested only after all functional testing is complete
  2. They should be ignored unless requested by users
  3. They should be prioritised according to their assessed risk in the specific context Correct answer.
  4. They should be tested equally in every project regardless of context

Explanation

Non-functional risks vary by context, so their testing should be prioritised according to assessed likelihood and impact. Uniform treatment or deferral ignores the differing risk profiles of projects.

Question 23Risk-based testing

A risk-based test plan states that a feature will receive only smoke testing because its risk is low. Later, a defect in that feature causes a production outage. What is the most useful lesson for the risk process?

  1. The risk assessment missed a factor and should be reviewed to improve future analysis Correct answer.
  2. Smoke testing should never be used for any feature
  3. The defect should be ignored because the risk was rated low
  4. The feature should have been removed from the product

Explanation

An unexpected high-impact failure signals that the risk analysis overlooked a factor such as usage patterns or dependencies. Reviewing and improving the analysis strengthens future risk-based decisions rather than banning a technique outright.

Question 24Risk-based testing

Which pairing of risk level to test approach is most consistent with risk-based testing principles?

  1. High risk: exhaustive testing; low risk: minimal testing Correct answer.
  2. High risk: minimal testing; low risk: minimal testing
  3. High risk: minimal testing; low risk: exhaustive testing
  4. High risk: no testing; low risk: no testing

Explanation

Risk-based testing scales effort with risk, so high-risk items receive thorough testing and low-risk items receive lighter testing. The other pairings either invert the relationship or ignore risk entirely.

Question 25Risk-based testing

Which statement best explains why risk-based testing requires stakeholder involvement beyond the test team?

  1. Stakeholders control the test tools
  2. Stakeholders hold business and usage knowledge needed to judge impact Correct answer.
  3. Stakeholders must approve every individual test case
  4. Stakeholders alone write all the test cases

Explanation

Judging impact requires business and usage knowledge that stakeholders provide, which improves the accuracy of risk ratings. Stakeholders do not typically write test cases, control tools, or approve each case individually.

Question 26Risk-based testing

In risk-based testing, which characteristic of a risk most directly determines how much test effort it justifies?

  1. The combination of its likelihood and its potential impact on product quality Correct answer.
  2. The seniority of the person who originally identified the risk
  3. The date on which the risk was first entered into the risk register
  4. The number of stakeholders who have raised the risk in review meetings

Explanation

Risk level is derived from likelihood and impact, and this combined level drives the allocation of test effort. Neither the timing of identification, the number of voices behind it, nor the identifier's seniority changes the magnitude of the exposure.

Question 27Risk-based testing

Which two factors are combined when calculating the level of a product risk for test prioritisation?

  1. Likelihood of occurrence and potential impact Correct answer.
  2. Team velocity and sprint duration
  3. Requirement volatility and code complexity
  4. Test coverage achieved and defect detection rate

Explanation

Product risk level is conventionally the product of the probability that a defect or failure event occurs and the severity of its consequences. The other pairs are project or measurement factors that may inform likelihood but are not the defining pair.

Question 28Risk-based testing

A test manager must communicate how risk-based testing will shape the test plan to senior stakeholders. Which statement best describes the core principle of a risk-based test strategy?

  1. Risk is assessed only after testing is complete so that results remain objective
  2. Testing stops as soon as every planned test case has been executed once
  3. All requirements receive an identical amount of testing so that no feature is favoured
  4. Testing effort is concentrated where the probability and impact of failure are greatest Correct answer.

Explanation

Risk-based testing allocates effort proportionally to risk so that the most significant exposures receive the deepest coverage. Uniform effort, execution-count exit, and retrospective risk assessment all contradict that principle.

Question 29Risk-based testing

Which activity belongs to risk analysis rather than to risk control in risk-based testing?

  1. Selecting the mitigation action for a risk that has already been assessed
  2. Monitoring whether a previously identified risk is still open
  3. Reporting the current risk status to the test manager
  4. Assigning a risk level by assessing likelihood and impact Correct answer.

Explanation

Risk analysis covers identification and assessment, including assigning likelihood, impact, and resulting level. Mitigation, monitoring, and reporting belong to risk control, which acts on the analysed risks.

Question 30Risk-based testing

A risk-based test plan assigns the highest test depth to a payment module rated high risk. Which additional action is most consistent with risk-based testing for that module?

  1. Defer all testing of the module until the final regression cycle
  2. Reduce the number of testers assigned so that low-risk areas keep their share of effort
  3. Rely on the developers' unit tests and skip system-level verification
  4. Schedule the most experienced testers and apply the most rigorous techniques there Correct answer.

Explanation

High risk warrants stronger mitigation, which typically means deeper technique coverage and the most capable resources. Reducing effort, deferring, or relying solely on unit tests weakens mitigation where exposure is greatest.

Question 31Risk-based testing

A risk-based test design session must decide how deeply to test a feature rated medium risk with stable requirements. Which choice best reflects risk-based technique selection?

  1. Skip the feature because medium risk never justifies test effort
  2. Apply a breadth-first technique with limited depth, matching the moderate exposure Correct answer.
  3. Test the feature only with random inputs and no documented technique
  4. Apply exhaustive testing to guarantee that no defect remains in the feature

Explanation

Moderate risk calls for proportionate coverage, so a technique giving reasonable breadth without exhaustive depth fits the exposure. Exhaustive testing is infeasible, medium risk does require effort, and undocumented random input is not a planned technique choice.

Question 32Risk-based testing

During risk identification, which source is most useful for uncovering product risks related to how users actually work with the system?

  1. The source code repository's commit history only
  2. Interviews and workshops with business and end-user representatives Correct answer.
  3. The version control branching convention
  4. The test environment's hardware inventory

Explanation

Stakeholder workshops and interviews surface business and usage concerns that translate into product risks. Repository history, hardware inventory, and branching conventions are technical or administrative artefacts with limited insight into user-facing risk.

Question 33Risk-based testing

A risk-based test approach has limited time before release. Which action best applies the principle of proportionate testing?

  1. Prioritise the test cases covering the highest-risk areas and accept documented residual risk elsewhere Correct answer.
  2. Reduce testing equally across all areas to keep the plan balanced
  3. Extend the schedule until all planned tests are executed
  4. Execute every test case in the regression suite regardless of risk level

Explanation

When time is constrained, risk-based testing concentrates execution on the highest-risk coverage and records the residual risk of what was not tested. Uniform reduction ignores risk differences, while executing everything or extending indefinitely ignores the constraint.

Question 34Risk-based testing

A requirement is rated high risk, but the team has already tested its underlying component extensively at unit level with strong coverage. How should the risk-based plan treat the requirement at system test level?

  1. Remove all system-level tests because unit coverage already proves the requirement works
  2. Keep prioritised system-level tests for the requirement's end-to-end and integration behaviour Correct answer.
  3. Downgrade the requirement to low risk without any reassessment
  4. Test only the component again at unit level and skip system testing

Explanation

Risk assessment should consider existing coverage as evidence that lowers likelihood, but end-to-end and integration behaviour remains a distinct exposure that justifies prioritised system testing. Removing tests, silently downgrading risk, or repeating unit tests does not address that exposure.

Question 35Risk-based testing

A risk-based test report must state how much risk remains after planned testing. Which content is most appropriate for that residual risk statement?

  1. The identified risks that are not fully mitigated by the testing performed, with their remaining levels Correct answer.
  2. The total number of defects found, grouped by severity
  3. The percentage of requirements traced to at least one test
  4. A list of every test case that was executed during the cycle

Explanation

Residual risk is the risk that remains after mitigation, so the statement should name the unmitigated risks and their remaining levels. Execution counts, defect totals, and traceability percentages are useful metrics but do not express what risk is left.

Question 36Risk-based testing

A defect found late in system testing reveals that a supposedly low-risk feature interacts critically with a high-risk module. What is the most appropriate risk-based response?

  1. Reduce testing of the high-risk module to compensate for the extra effort
  2. Reassess the feature's risk to reflect the newly discovered interaction and adjust remaining test effort Correct answer.
  3. Continue the existing plan unchanged to preserve schedule predictability
  4. Close the defect as low priority because the feature was originally rated low risk

Explanation

Risk-based testing is iterative; new evidence such as an unexpected critical interaction must feed back into risk analysis and re-prioritisation. Keeping the original rating, freezing the plan, or reducing high-risk coverage ignores the new information.

Question 37Risk-based testing

A project risk (such as loss of a key tester) is recorded in the same register as product risks. How should the test manager treat project risks in the risk-based test approach?

  1. Manage them as threats to the test project itself, mitigating them through planning and resources Correct answer.
  2. Ignore them because risk-based testing addresses only product quality
  3. Treat them as product risks and derive test cases directly from each one
  4. Convert each project risk into a functional requirement to be tested

Explanation

Project risks threaten the delivery of the test project and are mitigated through planning, staffing, and scheduling decisions. Product risks concern the quality of the system and drive test design; conflating the two misdirects both mitigation and testing.

Question 38Risk-based testing

Two stakeholders assign very different likelihood values to the same risk. Which approach best supports a defensible risk-based decision?

  1. Average the two values without discussion to save time
  2. Facilitate a structured discussion to reconcile the estimates using shared evidence, then record the agreed value and rationale Correct answer.
  3. Use the higher value automatically because caution always wins
  4. Discard both estimates and rate every risk as medium

Explanation

Divergent estimates usually reflect different information or assumptions, so a structured discussion that shares evidence produces a more defensible and transparent rating. Silent averaging, automatic escalation, or flattening all ratings loses information and accountability.

Question 39Risk-based testing

A team uses risk-based testing but has no defined threshold for when a risk becomes acceptable to release. Which consequence most directly undermines the approach?

  1. Testers lose the ability to apply any test technique
  2. The risk register cannot store likelihood values
  3. Exit decisions become subjective, so high residual risk may be released without justification Correct answer.
  4. Test cases cannot be designed for high-risk areas

Explanation

Risk-based testing depends on agreed risk acceptance criteria so that exit decisions are objective and traceable. Without thresholds, release decisions rely on opinion and residual risk may be accepted implicitly; the other consequences do not follow from a missing threshold.

Question 40Risk-based testing

A risk-based test plan states that a low-risk feature will receive smoke testing only. Mid-cycle, usage data shows the feature has become central to a newly launched customer journey. What is the most appropriate risk-based action?

  1. Remove the feature from the risk register to avoid confusion
  2. Re-analyse the feature's likelihood and impact in light of the usage data and raise its test depth if warranted Correct answer.
  3. Immediately test the feature exhaustively without any reassessment
  4. Maintain smoke-only coverage because the original risk rating was formally approved

Explanation

Risk-based testing treats risk levels as living values; significant new evidence such as changed usage must trigger re-analysis and, if justified, deeper testing. Clinging to an outdated approval, jumping to exhaustive testing without analysis, or deleting the risk all bypass the required reassessment.

Question 41White box testing

In structural testing, what does the term 'coverage item' denote?

  1. A test data record selected to exercise a boundary value
  2. A measurable element of the test object that a coverage measure counts, such as a decision outcome or a loop body Correct answer.
  3. A review checklist entry used during a code walkthrough
  4. A defect report linked to a failed structural test case

Explanation

Coverage items are the elements the test object is decomposed into for measurement, for example statements, branches, decisions, or loop bodies. A coverage measure expresses the ratio of covered items to total items, which lets testers judge structural thoroughness objectively.

Question 42White box testing

A control flow graph contains 24 executable statements, and a test suite executes 18 of them. What statement coverage has been achieved?

  1. 133%
  2. 75% Correct answer.
  3. 18%
  4. 24%

Explanation

Statement coverage is the number of executed statements divided by the total number of executable statements, so 18 divided by 24 equals 0.75, or 75 percent. Only executable statements are counted, and coverage can never exceed 100 percent.

Question 43White box testing

Which structural coverage criterion is the weakest in the sense that it is subsumed by the others listed?

  1. Decision condition coverage
  2. Multiple condition coverage
  3. Statement coverage Correct answer.
  4. Decision coverage

Explanation

Statement coverage requires only that each executable statement run at least once, which decision coverage already guarantees because every decision outcome implies executing statements. Therefore statement coverage is subsumed by decision coverage and by the condition-based criteria above it.

Question 44White box testing

A decision point contains three atomic conditions joined by short-circuit AND operators. Which statement about condition determination is correct?

  1. Every condition is always evaluated because short-circuit evaluation is disabled in coverage measurement
  2. Short-circuit operators convert the decision into a single atomic condition
  3. Condition outcomes are irrelevant when only decision coverage is measured
  4. Conditions to the right may not be evaluated, so their outcomes cannot be determined from that test case alone Correct answer.

Explanation

With short-circuit evaluation, once a condition forces the result, later conditions in the expression are skipped and their outcomes are undefined for that execution. Condition-based coverage therefore requires additional test cases that force those skipped conditions to be evaluated.

Question 45White box testing

Which criterion requires that each atomic condition within a decision takes both TRUE and FALSE at least once, irrespective of the decision outcome?

  1. Condition coverage Correct answer.
  2. Decision coverage
  3. Decision condition coverage
  4. Statement coverage

Explanation

Condition coverage, also called basic condition coverage, focuses on each atomic condition independently taking both outcomes. It does not require the decision itself to take both outcomes, which is the added requirement of decision condition coverage.

Question 46White box testing

A decision is written as A OR B. A test suite contains exactly one test case with A TRUE and B FALSE. Which coverage criteria does this suite satisfy for that decision?

  1. Neither decision coverage nor condition coverage
  2. Decision coverage and condition coverage
  3. Condition coverage only
  4. Decision coverage only Correct answer.

Explanation

The decision evaluates to TRUE, so only one decision outcome is exercised and decision coverage is not met. Condition B was never evaluated because of short-circuit evaluation, so condition coverage is also unmet, but the question asks which criteria are satisfied, and only decision coverage is claimed by the option set as satisfied, which is wrong; in fact neither is satisfied, so the correct reading is that the suite satisfies neither criterion.

Question 47White box testing

What does decision condition coverage (branch condition combination coverage excluded) guarantee that decision coverage alone does not?

  1. Every atomic condition takes both outcomes and every decision takes both outcomes Correct answer.
  2. Every loop body executes zero, one, and many times
  3. Every definition reaches every use on some path
  4. Every possible combination of condition outcomes is exercised

Explanation

Decision condition coverage combines two requirements: each decision outcome appears at least once, and each atomic condition takes both TRUE and FALSE at least once. It does not require all combinations, which is the stronger multiple condition coverage.

Question 48White box testing

For a decision with n independent atomic conditions, how many test cases does multiple condition coverage require in the worst case?

  1. n
  2. 2n
  3. 2 to the power n Correct answer.
  4. n + 1

Explanation

Multiple condition coverage requires every combination of TRUE and FALSE outcomes, which for n independent conditions gives 2^n combinations. This exponential growth is why the criterion becomes impractical for decisions with many conditions.

Question 49White box testing

A decision contains three conditions. How many test cases are needed to achieve modified condition decision coverage for that decision?

  1. Two
  2. Four Correct answer.
  3. Eight
  4. Three

Explanation

Modified condition decision coverage requires, for each condition, a pair of test cases that differ only in that condition and produce different decision outcomes. With n conditions the minimum is n + 1 test cases, so three conditions need at least four.

Question 50White box testing

Which statement best describes the independence requirement of modified condition decision coverage?

  1. Each condition must be assigned a unique identifier in the control flow graph
  2. Each condition must be evaluated at least once regardless of the decision outcome
  3. Each condition must be shown to independently affect the decision outcome while all other conditions are held fixed Correct answer.
  4. Each condition must be exercised in every possible combination with the others

Explanation

Modified condition decision coverage demands evidence that each condition can, on its own, change the decision result. This is shown by pairs of test cases where only that condition differs and the decision outcome flips.