Software Testing Fundamentals Flashcards

Question 1

What is the main purpose of software testing?

Accepted Answer

Software testing is the process of evaluating a program to find defects and to gain confidence that it meets its stated requirements and behaves as expected. Testing cannot prove that software is free of all errors, but it reduces risk by revealing failures before users encounter them.

Question 2

What is the difference between an error, a defect, and a failure?

Accepted Answer

An error is a human mistake made while writing requirements, designs, or code. The error can introduce a defect, which is a flaw in the software artifact. When the defect is executed under certain conditions, it can produce a failure, which is an observable departure from the expected behavior.

Question 3

Why is it impossible to test software exhaustively?

Accepted Answer

Exhaustive testing would require running every possible combination of inputs, states, and environments, and even modest programs have far more combinations than time allows. Testers therefore sample the input space using risk and technique. Testing can show that defects are present, but it cannot show that none remain.

Question 4

What does the principle of early testing mean in practice?

Accepted Answer

Early testing means starting test activities as soon as possible in the development lifecycle, including reviewing requirements and designs before code exists. Defects found early are usually cheaper and easier to fix than those found after release. Early involvement of testers also helps clarify ambiguous requirements before they are built into the product.

Question 5

What is the difference between verification and validation?

Accepted Answer

Verification checks whether the software is built correctly, meaning it conforms to its specifications and design documents. Validation checks whether the right software is being built, meaning it meets the actual needs of users and stakeholders. A product can pass verification yet still fail validation if the specification itself was wrong.

Question 6

What is a test case, and what should it contain?

Accepted Answer

A test case is a set of preconditions, inputs, actions, and expected results designed to check one specific behavior of the software. A good test case has a clear purpose, can be repeated by anyone with the same outcome, and records the actual result so that a pass or fail decision is unambiguous.

Question 7

What is a test oracle, and why does it matter?

Accepted Answer

A test oracle is any mechanism that tells the tester whether an observed output is correct, such as a specification, a previous trusted version, a calculation, or an experienced person's judgment. Without an oracle, a test can run and produce output yet still give no reliable verdict about whether the software behaved correctly.

Question 8

What is regression testing, and when is it performed?

Accepted Answer

Regression testing is the repeat execution of existing tests to confirm that previously working behavior still works after a change such as a bug fix, new feature, configuration update, or refactoring. It matters most before a release, because changes in one area can unintentionally break functionality elsewhere.

Question 9

What is equivalence partitioning, and how is it used?

Accepted Answer

Equivalence partitioning divides input data into groups, called partitions, where the software is expected to treat every value in a group the same way. The tester then picks one representative value from each valid and invalid partition, which reduces the number of tests while still covering each distinct kind of behavior.

Question 10

What is boundary value analysis, and why do testers focus on edges?

Accepted Answer

Boundary value analysis tests values at the edges of each valid partition, along with values just outside those edges. Testers focus on boundaries because mistakes are common at limits, such as using a strict comparison where an inclusive one was intended. For a range from 1 to 100, test 0, 1, 100, and 101.

Question 11

How does decision table testing help testers cover combinations of conditions?

Accepted Answer

Decision table testing lists every combination of input conditions in columns, along with the expected action for each combination, so that no logical case is overlooked. Each column becomes one test case. The technique is useful when business rules depend on several interacting conditions, such as discount eligibility based on membership and order size.

Question 12

What is state transition testing, and what does it check?

Accepted Answer

State transition testing models a system as a set of states, the events or inputs that trigger changes, and the transitions that follow. Tests are designed to cover valid transitions, invalid transitions that should be rejected, and sequences of events that lead to important states. Login flows are a typical example.

Question 13

What is the difference between black box and white box testing?

Accepted Answer

Black box testing evaluates software from the outside, using inputs and observed outputs without considering internal code structure. White box testing uses knowledge of the code, such as its branches and statements, to design tests that exercise internal paths. Both approaches are complementary, and many test strategies combine them.

Question 14

What is exploratory testing, and how does it differ from scripted testing?

Accepted Answer

Exploratory testing is simultaneous learning, test design, and test execution, where the tester investigates the software guided by curiosity and experience rather than following a predetermined script. Scripted testing follows written steps and expected results prepared in advance. Both have value, and exploratory testing often finds problems that scripts did not anticipate.

Question 15

How do pairwise testing and combinatorial testing reduce the number of tests?

Accepted Answer

Combinatorial testing selects combinations of parameter values rather than testing every possible combination. Pairwise testing is a common form that ensures every pair of values from any two parameters appears together in at least one test. Pairwise coverage often finds many faults with far fewer tests than exhaustive combinations.

Question 16

What is error guessing, and when is it most useful?

Accepted Answer

Error guessing is a technique in which the tester uses past experience, knowledge of the software, and common programming mistakes to predict likely defects, then designs tests to expose them. It is most useful as a supplement to systematic techniques, especially when time is short or the team has strong domain knowledge.

Question 17

What are the main levels of testing in a typical lifecycle?

Accepted Answer

The main levels are unit testing, integration testing, system testing, and acceptance testing. Each level focuses on a different scope, from individual components tested in isolation up to the complete system evaluated against business needs. Moving up the levels generally means tests involve more components and more of the real environment.

Question 18

What is unit testing, and who usually performs it?

Accepted Answer

Unit testing checks the smallest testable parts of a program, such as a function, method, or class, in isolation from the rest of the system. Developers usually write and run unit tests, often using stubs or mocks to replace dependencies. Fast unit tests give quick feedback during coding.

Question 19

Why does integration testing focus on the interfaces between components?

Accepted Answer

Components that work correctly alone can still fail when combined, because they may pass data in unexpected formats, call each other in the wrong order, or misunderstand shared assumptions. Integration testing checks these interactions, usually by combining components incrementally and verifying that data flows and calls behave as the design intends.

Question 20

What is system testing, and what does it evaluate?

Accepted Answer

System testing evaluates the complete, integrated application against its specified requirements, in an environment that closely resembles production. It covers functional behavior along with nonfunctional qualities such as performance, security, usability, and reliability. An independent test team often leads this level. This level gives the first full view of the product.

Question 21

What is acceptance testing, and who typically carries it out?

Accepted Answer

Acceptance testing determines whether the software is acceptable for delivery and use, based on business requirements and user needs. It is often carried out by customers, end users, or product owners, and it may include user acceptance testing and operational acceptance testing. Passing it is commonly a condition for release.

Question 22

What is functional testing compared with nonfunctional testing?

Accepted Answer

Functional testing checks what the software does, verifying that features perform their specified actions and produce correct outputs for given inputs. Nonfunctional testing checks how well the software performs those actions, covering qualities such as speed, scalability, security, accessibility, and usability.

Question 23

What is smoke testing, and when is it applied?

Accepted Answer

Smoke testing is a brief set of tests that checks whether the most critical functions of a new build work at all. If the build fails smoke testing, it is usually rejected before deeper testing begins, saving effort. It is commonly run right after each new build is deployed to a test environment.

Question 24

What is the purpose of sanity testing, and how does it differ from smoke testing?

Accepted Answer

Sanity testing is a narrow check performed after a small change, such as a bug fix, to confirm that the specific problem is resolved and nothing obvious broke around it. Smoke testing is broader and checks overall build stability, while sanity testing focuses on a targeted area.

Question 25

What are the typical phases of the software test process?

Accepted Answer

A typical test process includes planning, analysis and design, implementation, execution, and completion or closure. Planning defines scope, approach, resources, and schedule. Each phase produces outputs, such as test conditions, test cases, results, and a summary report, that feed the next phase.

Question 26

What is a test plan, and what should it describe?

Accepted Answer

A test plan is a document that describes the objectives, scope, approach, resources, schedule, and risks for testing a particular release or project. It states what will be tested and what will not, the entry and exit criteria, and who is responsible for each activity.

Question 27

What are entry and exit criteria in testing?

Accepted Answer

Entry criteria are the conditions that must be met before a test activity can begin, such as a stable build, available test environment, and approved test cases. Exit criteria are the conditions that must be satisfied before testing is considered complete, such as a coverage target or an agreed number of open critical defects.

Question 28

What is a test strategy, and how does it differ from a test plan?

Accepted Answer

A test strategy states the general testing approach, principles, and standards that apply across projects or across an organization. A test plan is project specific, describing how the strategy will be applied to a particular release, including schedule, resources, and scope.

Question 29

What is a defect report, and what key details should it include?

Accepted Answer

A defect report, also called a bug report, is a document that describes a suspected problem so developers can reproduce and fix it. Useful reports include a clear title, steps to reproduce, the expected and actual results, the environment and build version, severity, and any supporting evidence such as logs or screenshots.

Question 30

What is a traceability matrix, and why is it valuable?

Accepted Answer

A traceability matrix links requirements to the test cases that verify them, and optionally to defects found during testing. It shows whether each requirement has test coverage and reveals gaps where a requirement has no tests. It also helps teams assess the impact of a requirement change on existing tests.

Question 31

What is the purpose of a test summary report?

Accepted Answer

A test summary report communicates the outcome of a testing effort to stakeholders at its conclusion. It typically summarizes the tests executed, passed, failed, and blocked, the coverage achieved, the open defects and their severity, and risks that remain. Its purpose is to support an informed decision about release readiness.

Question 32

Why is test environment management important in the test process?

Accepted Answer

A test environment must resemble production closely enough that results are meaningful, including the right hardware, software versions, configuration, and test data. Poor environment management causes false failures, missed defects, and wasted time chasing problems that are not in the software. Controlled, documented environments make results repeatable and trustworthy.

Question 33

What is the defect life cycle, and what are its common stages?

Accepted Answer

The defect life cycle describes how a defect moves from discovery to resolution. Common stages include new or open, assigned, in progress, fixed, verified or retested, and closed. Some teams also use reopened when a fix fails verification, and deferred or rejected when a report will not be fixed.

Question 34

How is defect severity different from defect priority?

Accepted Answer

Severity describes the technical impact of a defect, such as a crash, data loss, or a cosmetic typo. Priority describes how urgently it should be fixed, based on business needs. The two can differ, since a severe crash in a rarely used report may be less urgent than a typo on the home page.

Question 35

What is a defect density metric, and how is it calculated?

Accepted Answer

Defect density is a metric that compares the number of confirmed defects to the size of the software, commonly measured in defects per thousand lines of code. It is calculated by dividing the number of defects by the size measure. Teams use it to compare modules.

Question 36

What is test automation, and which tests are good candidates for it?

Accepted Answer

Test automation uses scripts and tools to execute tests and compare actual results with expected results without manual effort. Good candidates are stable, repetitive checks that run often, such as regression suites, smoke tests, and calculations with many input combinations. Exploratory testing usually remains manual because it depends on human judgment.

Question 37

What are the main benefits and limits of test automation?

Accepted Answer

Benefits include fast, consistent execution, rapid feedback after changes, broader coverage of repetitive checks, and freeing testers for more complex work. Limits include the cost of building and maintaining scripts, the risk of brittle tests that break when the interface changes, and automation cannot judge usability or notice problems no one scripted.

Question 38

What is continuous integration, and how does testing fit into it?

Accepted Answer

Continuous integration is a practice in which developers merge code changes frequently, and each change triggers an automated build and test run. Testing fits in as fast automated checks, typically unit and smoke tests, that give quick feedback, with broader suites run on a schedule or before release.

Question 39

How should testers decide when testing is complete?

Accepted Answer

Testers decide completion by checking exit criteria agreed in the test plan, such as planned tests executed, coverage targets reached, and no open critical defects. Because exhaustive testing is impossible, completion is a judgment about risk rather than proof of zero defects. Stakeholders should review the remaining risks before signing off.

Question 40

What habits help testers communicate effectively with developers?

Accepted Answer

Effective testers report facts rather than opinions, describing observed behavior and reproduction steps without blame. They confirm reproducibility before reporting, keep reports concise, and separate confirmed defects from questions or suspicions. They also stay available to explain findings and retest fixes promptly, building trust over time.

Software Testing Fundamentals Flashcards

1Core Testing Principles

2Test Design Techniques

3Levels and Types of Testing

4Test Process and Documentation

5Defects, Metrics and Automation

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