Fast definitions for terminology interviewers often use to check whether basic QA concepts are separated correctly.
QAProcess-oriented preventionImprove the way quality is built through standards, reviews, process, feedback, and prevention.
QCProduct-oriented controlEvaluate work products or the product to identify quality problems.
TestingEvaluation activityProvide information about quality and risk; testing can reveal defects but cannot prove their absence.
DebuggingFind and fix the causeInvestigate the cause of a failure or defect and change code, configuration, data, or another implementation element.
VerificationAgainst specified requirementsAsk whether the product or work product satisfies specified requirements: are we building it correctly?
ValidationAgainst user/stakeholder needsAsk whether the product is fit for intended use and stakeholder needs: are we building the right product?
Seven testing principles
Interview · Very common
The seven principles are frequent foundation-level interview material and explain why testing must be selective and context-driven.
Testing shows presence of defectsTests can reveal failures and defects; passing tests cannot prove that no defects remain.
Exhaustive testing is impossibleExcept for very small finite spaces, select tests using risk, techniques, priorities, and constraints.
Early testing saves time and moneyReview requirements, designs, and risks early so defects are found before expensive rework.
Defects cluster togetherA relatively small number of components often contains a large share of observed defects.
Agile, shift-left & Continuous Integration
Interview · Common
The core idea is faster, cheaper feedback and shared quality ownership—not merely moving the same manual tests earlier.
RefinementChallenge ambiguity, examples, acceptance criteria, risks, testability, observability, and dependencies before coding.
During developmentReview design/code, pair on tests, validate contracts, and add component/API checks close to the change.
Continuous IntegrationRun fast deterministic checks on each relevant change; failures should be owned, diagnosable, and acted on quickly.
Post-deploy / shift-rightUse monitoring, synthetic checks, canaries, feature flags, and rollback signals as additional evidence after deployment.
Software Testing Life Cycle / test process / test activities
Interview · Very common
ISTQB defines seven test activities, but the syllabus list is not a chronological seven-step flow. A useful simplified working sequence is planning → analysis → design → implementation → execution → completion, while test monitoring and control runs continuously across all of them.
1. Test planningDefine objectives, scope, approach, resources, schedule, risks, metrics, and completion criteria. Planning starts early and can be revised later.
2. Test analysisStudy the test basis and identify testable features, risks, and test conditions: what needs to be tested?
3. Test designTurn test conditions into test cases, coverage items, expected results, and data/environment needs: how should it be tested?
4. Test implementationPrepare procedures/scripts, suites, data, environments, automation, and execution order so the designed tests can actually run.
5. Test executionRun tests, compare actual and expected results, record evidence, analyze anomalies, and report failures or defects where appropriate.
6. Test completionEvaluate achieved evidence, unresolved risks, defect status and lessons, then archive or hand over reusable testware and communicate completion.
Continuous: Test monitoring & controlRuns across the whole test effort once a plan or baseline exists. Compare actual progress and results with expectations, then adjust priorities, scope, resources, schedule, depth, or the plan during analysis, design, implementation, execution, and completion.
Test strategy vs plan vs approach
Interview · Very common
These terms are frequently collapsed in interviews; separate the scope and decision each one documents instead of memorizing one rigid template.
Test policyOrganization-level principlesDefines high-level expectations, governance, or principles for testing across an organization or product family.
Test strategyReusable high-level directionDefines a broader approach for obtaining quality evidence across a product, programme, or long-lived initiative.
Test planSpecific test effortDefines how and when objectives will be achieved for a project, release, iteration, migration, or major change.
Test approachHow the plan gets evidenceSelected levels, types, techniques, priorities, exploratory work, automation, independence, data, and environments.
Test scheduleWhen and in what orderPlaces activities, dependencies, milestones, and execution order in time.
Risk-based testing
Interview · Common
Allocate earlier and deeper testing effort where product risk is highest, then make residual risk explicit when constraints force trade-offs.
Risk levelA simple model is likelihood × impact; use the team's scale and avoid fake mathematical precision.
Likelihood signalsComplexity, novelty, many dependencies, code churn, weak observability, defect history, and unfamiliar technology.
Impact signalsRevenue, safety, security, data loss, legal exposure, user volume, blocked core tasks, and recovery cost.
High risk responseTest earlier, with stronger techniques, broader data, more independence, and more focused regression.
Test prioritization under time pressure
Interview · Common
When everything cannot be tested, make the selection logic and resulting residual risk explicit instead of pretending coverage is unchanged.
1. Release blockersDeployment/startup, authentication, data access, payments/core workflow, and critical integrations.
2. Changed high-risk areaThe direct change plus dependencies and known regression hotspots.
3. Critical user journeysHighest-value, highest-volume, or highest-consequence end-to-end paths.
4. Important defect fixesConfirm high-impact fixes and run targeted regression around the affected area.
5. Broader regressionExpand by remaining risk, usage, defect history, and available time.
Good requirement characteristics
Interview · Very common
A strong interview answer checks both the wording of one requirement and whether the set of requirements works coherently together.
Clear & unambiguousA reasonable reader should not be able to derive several different intended behaviors.
Verifiable / testableThere must be observable evidence that can decide whether the requirement is satisfied.
CompleteRequired conditions, inputs, outcomes, errors, boundaries, and constraints are present where needed.
Feasible & necessaryThe requirement is achievable within real constraints and exists for a stakeholder, business, regulatory, or system need.
Singular / atomicIt expresses one main obligation rather than several unrelated behaviors joined together.
Consistent & traceableIt does not contradict known rules and its origin plus downstream consequences can be recovered.
Requirements-to-requirements relationships
Interview · Common
Requirements are a graph, not a flat list; interview-ready review includes decomposition, dependencies, conflicts, and overlap between requirements.
Derived from / refinesA lower-level requirement makes a higher-level need more concrete while preserving its intent.
Parent / childA broad capability is decomposed into smaller requirements that together implement the parent.
Depends on / prerequisiteOne requirement only makes sense or can operate when another requirement or condition is satisfied.
Constrains / interacts withOne requirement limits another or two requirements affect the same state, data, interface, or workflow.
Conflicts / overlapsRequirements may be mutually incompatible or duplicate the same rule with inconsistent wording.
InspectionA formal review with defined roles, preparation, entry criteria, defect logging, moderation, and follow-up.
Static analysisTools examine code or models for properties such as control/data flow, complexity, unreachable code, dependency rules, or security findings.
Test levels
Interview · Very common
A test level answers where the test object sits in the system decomposition; do not mix levels with test types or regression labels.
Component / unitSmallest useful test objectFunctions, classes, modules, or components, usually tested in isolation or near isolation.
Component integrationBetween internal componentsInterfaces and interactions between components, modules, services, or subsystems inside the product.
SystemComplete integrated systemBehavior and quality of the complete system against system-level requirements and risks.
System integrationBetween systemsInterfaces between the system under test and external services, platforms, partner systems, or protocols.
AcceptanceStakeholder readinessEvidence that the system is acceptable for users, business, contractual, operational, or regulatory needs.
Test types
Interview · Very common
A test type answers what objective or quality question is being evaluated; the same type can be applied at several test levels.
Functional testingWhat the system doesEvaluate functions, business rules, calculations, permissions, flows, and other specified behavior.
Non-functional testingHow well it worksEvaluate quality characteristics such as performance, reliability, security, compatibility, interaction capability, or safety.
Black-box testingFrom specified behaviorDerive tests without using internal code structure; focus on inputs, outputs, rules, states, and observable behavior.
White-box testingFrom internal structureDerive tests from code or architecture structure, for example statements, branches, conditions, or paths.
Quality characteristics
Interview · Common
Use canonical quality-characteristic names in interviews, then translate each one into practical testing questions.
Functional suitabilityFunctional completeness, correctness, and appropriateness for intended tasks.
Performance efficiencyTime behavior, throughput, capacity, and resource utilization under relevant load.
CompatibilityCoexistence and interoperability with required systems, platforms, and environments.
Interaction capabilityRecognizability, learnability, operability, error protection, engagement, inclusivity, and accessibility of interaction.
ReliabilityAvailability, fault tolerance, recoverability, and behavior over time or under faults.
Test pyramid & testing quadrants
Interview · Common
These are planning heuristics, not laws; use them to explain feedback speed, scope, and the different purposes of technical and business-facing testing.
Test pyramidPrefer many fast lower-level checks, fewer service/integration checks, and a smaller number of expensive UI end-to-end checks when the architecture supports it.
Pyramid purposeOptimize feedback speed, diagnosability, maintenance cost, and coverage—not a fixed percentage at each layer.
Testing quadrantsA collaboration model that distinguishes technology-facing vs business-facing and support-the-team vs critique-the-product activities.
Interview cautionNeither model replaces risk analysis; a product can legitimately need more integration, hardware, visual, accessibility, or end-to-end evidence.
Test design approaches & technique families
Interview · Very common
Start from the formal family name, then name the techniques; this is the interview-friendly map for choosing how tests are derived.
Black-box / specification-basedDerive tests from requirements, rules, models, interfaces, and observable behavior; includes Equivalence Partitioning, Boundary Value Analysis, decision tables, and state transitions.
White-box / structure-basedDerive tests from internal structure; common foundation examples are statement and branch coverage.
Experience-basedUse tester knowledge and learning; includes error guessing, exploratory testing, and checklist-based testing.
Collaboration-based approachesDerive shared examples with stakeholders, for example user-story collaboration, acceptance criteria, and Acceptance Test-Driven Development.
Equivalence Partitioning
Interview · Very common
Divide a large input or state domain into partitions expected to behave similarly, then choose representative values from each meaningful partition.
Equivalence PartitioningGroup equivalent behaviorIdentify valid and invalid classes based on actual rules or expected behavior.
ExampleIf age must be 18–65: partitions are <18, 18–65, and >65; representative values might be 17, 30, and 66.
Suspension criteriaConditions that make continued testing wasteful or unsafe, such as an invalid build, broken environment, or unavailable critical dependency.
Resumption criteriaSpecific evidence that the blocking condition has been resolved and test results can be trusted again.
Smoke vs sanity
Interview · Very common
These industry labels are not universally standardized, so explain the purpose you use rather than arguing about one absolute definition.
Smoke testingBroad and shallowA small set of critical checks that decides whether a build or environment is stable enough for deeper testing.
Sanity testingFocused and narrowA targeted check around a small change or area to decide whether more detailed testing is worthwhile.
Typical smoke examplesApplication starts, login works, core navigation loads, critical API/dependency is reachable, core transaction can complete.
Interview answerState your team's convention and the decision each suite supports; acknowledge that organizations use the labels differently.
Statement vs branch coverage
Interview · Common
Coverage tells you which implementation structure was exercised; it does not prove that assertions, requirements, or test data are good.
Statement coverageExecuted executable statements ÷ total executable statements × 100%.
Know the normal state flow but emphasize that exact statuses depend on the workflow; what matters is ownership and a verifiable resolution path.
New / OpenA problem is reported with enough evidence for triage and investigation.
Triaged / AssignedImpact, validity, ownership, priority, and next action are agreed.
In progress / FixedThe cause is addressed and a candidate fix becomes available for verification.
Retest / VerifiedQA or another responsible party confirms the original failure no longer occurs in the intended build/environment.
ClosedThe resolution is accepted and the workflow is complete.
Acceptance, User Acceptance Testing, alpha & beta
Interview · Common
These labels overlap in real projects, so distinguish the test level, the stakeholder purpose, and who performs the testing.
Acceptance testingA test level that evaluates whether the system is acceptable against user, business, contractual, operational, or regulatory criteria.
User Acceptance TestingUser acceptance testingAcceptance testing from the customer or user perspective to confirm real business work can be completed.
Alpha testingControlled pre-release testing performed at or for the developing organization, often by internal or invited users.
Beta testingPre-release use by selected external users in realistic environments to expose issues and gather feedback.
QA metrics that answer a decision
Interview · Common
Start with the decision or question, then choose a metric; raw counts without denominator, scope, or context are easy to misuse.
ProgressExecuted vs planned relevant scope, preferably split by feature, risk, environment, or release objective.
Defect signalOpen/closed trend, impact, age, reopen rate, or escaped defects where those measures support a decision.
CoverageRequirements, risks, techniques, code, platforms, or other coverage—always state what the denominator means.
A release decision is a risk decision supported by evidence; pass percentage alone is not a sufficient release argument.
Critical flowsRequired user and business journeys pass in the relevant release candidate and environment.
Change coverageChanged areas and dependencies received appropriate confirmation and regression evidence.
Open defectsKnown defects are understood by impact, exposure, workaround, and release consequence.
Residual riskUntested or partially tested areas, assumptions, environment gaps, and known limitations are visible to decision-makers.
Operational readinessMonitoring, rollback/feature flags, migration/recovery, support, and runbook needs are ready where relevant.
Root cause & defect prevention
Interview · Occasional
A useful Root Cause Analysis goes beyond developer made a mistake and identifies what allowed the defect to be introduced and escape.
SymptomThe failure that users, monitoring, or tests observed.
Technical causeThe immediate code, configuration, data, design, dependency, or infrastructure mechanism that produced the failure.
Escape causeWhy reviews, tests, monitoring, or release controls did not detect the problem earlier.
System causeA weakness in requirements, process, architecture, ownership, tooling, environment, incentives, or feedback loops.
Preventive actionChange the system with clearer rules, safer defaults, automated checks, testability, observability, review prompts, or guardrails.
Static vs dynamic testing
Interview · Very common
Static and dynamic describe whether the test object is executed, not a test level or a quality characteristic.
Static testingNo execution of the test objectEvaluate requirements, designs, code, test cases, or other work products through reviews or static analysis.
Dynamic testingExecute the test objectRun software or a system, observe behavior, and compare results with expectations or other oracles.
Why static mattersIt can find ambiguity, inconsistency, unreachable code, standards violations, and design problems before runnable software exists.