Software Testing Interview Questions

Introduction to Software Testing

Software testing is an activity to check whether the actual results match the expected results and to ensure that the software system is defect-free. It involves execution of a software component or system component to evaluate one or more properties of interest.

Software testing also helps to identify errors, gaps or missing requirements in contrary to the actual requirements. It can be either done manually or using automated tools.

The development of large software systems is a complex and error prone process. Faults might occur at any development stage and they must be identified and removed as early as possible to stop their propagation and reduce verification costs. Quality engineers must be involved in the development process since the very early phases to identify required qualities and estimate their impact on the development process. Their tasks span over the whole development cycle and go beyond the product deployment through maintenance and post mortem analysis. Developing and enacting an effective quality process is not a simple task, but it requires that we integrate many quality-related activities with product characteristics, process organization, available resources and skills, and budget constraints

.
1. What is the Software Testing?

A set of activities conducted with the intent of finding errors in software.

2. What is Bug?

A fault in a program which causes the program to perform in an unintended or unanticipated manner.

3)What is PDCA cycle and where testing fits in?

There are four steps in a normal software development process. In short, these steps are referred as PDCA.

PDCA stands for Plan, Do, Check, Act.

Plan: It defines the goal and the plan for achieving that goal.
Do/ Execute: It depends on the plan strategy decided during the planning stage. It is done according to this phase.
Check: This is the testing part of the software development phase. It is used to ensure that we are moving according to plan and getting the desired result.
Act: This step is used to solve if there any issue occurs during the check cycle. It takes appropriate action accordingly and revises the plan again.

The developers do the "planning and building" of the project while testers do the "check" part of the project

4.What is Acceptance Testing?

Testing conducted to enable a user/customer to determine whether to accept a software product. Normally performed to validate the software meets a set of agreed acceptance criteria.

5. What are the categories of defects?

There are three main categories of defects:

Wrong: The requirements have been implemented incorrectly. This defect is a variance from the given specification.
Missing: There was a requirement given by the customer and it was not done. This is a variance from the specifications, an indication that a specification was not implemented, or a requirement of the customer was not noted properly.
Extra: A requirement incorporated into the product that was not given by the end customer. This is always a variance from the specification, but may be an attribute desired by the user of the product. However, it is considered a defect because it's a variance from the existing requirements.

6) What is the difference between a white box, black box, and gray box testing?

Black box Testing: The strategy of black box testing is based on requirements and specification. It requires no need of knowledge of internal path, structure or implementation of the software being tested.

White box Testing: White box testing is based on internal paths, code structure, and implementation of the software being tested. It requires a full and detail programming skill.

Gray box Testing: Gray Box testing is testing technique performed with limited information about the internal functionality of the system. Gray Box testers have access to the detailed design documents along with information about requirements.

Gray Box tests are generated based on the state-based models, UML Diagrams or architecture diagrams of the target system.

7)What are the advantages of designing tests early in the lifecycle?

Designing tests early in the life cycle prevent defects from being in the main code.

8. What is Accessibility Testing?

Accessibility testing is used to verify whether a software product is accessible to the people having disabilities (deaf, blind, mentally disabled ) etc.

9)Which is the best testing model?

In real projects, tailored models are proven to be the best, because they share features from The Waterfall, Iterative, Evolutionary models, etc., and can fit into real lifetime projects. Tailored models are most productive and beneficial for many organizations. If it's a pure testing project, then the V model is the best.

10)What is the difference between verification and validation?

Verification is a review without actually executing the process while validation is checking the product with actual execution. For instance, code review and syntax check are verification while actually running the product and checking the results is validation.

11)What is Ad Hoc Testing?

A testing phase where the tester tries to 'break' the system by randomly trying the system's functionality.

12)What is Agile testing?

Agile testing is a testing practice that uses agile methodologies i.e. follow test-first design paradigm.

13)What is the difference between latent and masked defects?

A latent defect is an existing defect that has not yet caused a failure because the sets of conditions were never met.

A masked defect is an existing defect that hasn't yet caused a failure just because another defect has prevented that part of the code from being executed.

14) What is Application Programming Interface (API)?

Application Programming Interface is a formalized set of software calls and routines that can be referenced by an application program in order to access supporting system or network services.

15)What is GUI Testing?

GUI or Graphical user interface testing is the process of testing software user interface against the provided requirements/mockups/HTML designs.

16)What is Dynamic Testing?

It is the testing done by executing the code or program with various input values and output is verified.

17)What is Static Testing?

Manual verification of the code without executing the program is called as static testing. In this process, issues are identified in code by checking code, requirement and design documents.

18) What is Monkey Testing/Random Testing?

Testing conducted on an application without any plan and carried out with tests here and there to find any system crash with an intention of finding tricky defects is called monkey testing.

19)What is Positive Testing?

Testing conducted on the application to determine if a system works. Basically known as “test to pass” approach.

20)What is Negative Testing?

Testing Software with a negative approach to check if the system is not “showing error when not supposed to” and “not showing error when supposed to”.

21)How does testing affect risk?

A risk is a condition that can result in a loss. Risk can only be controlled in different scenarios but not eliminated completely. A defect normally converts to a risk.

22)What is Bottom-up testing?

The Bottom-up testing is a testing approach which follows integration testing where the lowest level components are tested first, after that the higher level components are tested. The process is repeated until the testing of top-level component.

23) What is Backus-Naur Form?

A metalanguage used to formally describe the syntax of a language.

24)What is Baseline Testing?

In Baseline testing, a set of tests is run to capture performance information. Baseline testing improves performance and capabilities of the application by using the information collected and make the changes in the application. Baseline compares the present performance of the application with its own previous performance.

25)Can you explain calibration?

It includes tracking the accuracy of the devices used in the production, development, and testing. Devices used must be maintained and calibrated to ensure that it is working in good order.

26) What is Boundary Testing?

Test which focuses on the boundary or limit conditions of the software being tested. (Some of these tests are stress tests).

27)What is full form of CMMI?

Capability Maturity Model Integration

28)What is Dependency Testing?

Examines an application's requirements for pre-existing software, initial states, and configuration in order to maintain proper functionality.

29)What is Priority?

It indicates the importance or urgency of fixing a defect

30)What is Regression Testing?

Verifying existing functional and non-functional area after making changes to the part of the software or addition of new features.

31)What is Recovery Testing?

Checking if the system is able to handle some unexpected unpredictable situations is called recovery testing.

32)What is Defect Age?

The time gap between the date of detection & date of closure of a defect.

33)What is Bucket Testing?

Bucket testing is also known as A/B testing. It is mostly used to study the impact of the various product designs in website metrics. Two simultaneous versions are run on a single or set of web pages to measure the difference in click rates, interface, and traffic.

34)What is Test Harness?

Test Harness is configuring a set of tools and test data to test an application in various conditions, which involves monitoring the output with expected output for correctness.

The benefits of Testing Harness are: Productivity increase due to process automation and increase in product quality

35)What is Emulator?

A device, computer program, or system that accepts the same inputs and produces the same outputs as a given system.

36) What is alpha and beta testing?

These are the key differences between alpha and beta testing:

No.	Alpha Testing	Beta Testing
1)	It is always done by developers at the software development site.	It is always performed by customers at their own site.
2)	It is also performed by Independent testing team.	It is not be performed by Independent testing team.
3)	It is not open to the market and public.	It is open to the market and public.
4)	It is always performed in a virtual environment.	It is always performed in real time environment.
5)	It is used for software applications and projects.	It is used for software products.
6)	It follows the category of both white box testing and Black Box Testing.	It is only the kind of Black Box Testing.
7)	It is not known by any other name.	It is also known as field testing.

37)Explain bug leakage and bug release?

Bug Leakage: When a customer or end user discovered a bug which can be detected by the testing team. Or when a bug is detected which can be detected in the previous build then this is called as Bug Leakage.

Bug release: is when a build is handed to testing team with knowing that defect is present in the release. The priority and severity of the bug are low. It is done when customer want the application on the time. A customer can tolerate the bug in the released then the delay in getting the application and the cost involved in removing that bug. These bugs are mentioned in the Release Notes handed to the client for the future improvement chances.

38)What are Error guessing and Error seeding?

Error Guessing is a test case design technique where the tester has to guess what faults might occur and to design the tests to represent them.

Error Seeding is the process of adding known faults intentionally in a program for the reason of monitoring the rate of detection & removal and also to estimate the number of faults remaining in the program.

39)Explain Statement coverage?

Statement Coverage is a metric used in White Box Testing. Statement coverage is used to ensure that all the statement in the program code is executed at least once. The advantages of Statement Coverage are:

- Verifies that written code is correct.
- Measures the quality of code written.
- Determine the control flow of the program.
- To Calculate Statement Coverage:
- Statement Coverage = Statements Tested / Total No. of Statements.

40)Define Inspection?

Inspection is basically a check-up process. It is a quality improvement process for the writing material, considered as a group review.
Basically, two aspects involve under this –product improvement and process improvement.

41) In which phase, number of defects are more – designing phase or coding phase?

It will be more in the designing phase than the coding phase.

One of the major and most frequently occurring defects is that the product does not cover the complete customer requirements.
Another defect can be a wrong architecture.

The third one is a technical decision.

This way, the design phase is the most critical phase.

42)Define Quality Audit?

Quality Audit – It is a systematic examination to determine whether all is going as planned, i.e. whether the goal and plans are strictly followed. It is an independent examination.

43)What is coverage and what are the different types of coverage techniques?

Coverage is a measurement used in software testing to describe the degree to which the source code is tested. There are three basic types of coverage techniques as shown in the following figure:

Statement coverage: This coverage ensures that each line of source code has been executed and tested.
Decision coverage: This coverage ensures that every decision (true/false) in the source code has been executed and tested.
Path coverage: In this coverage we ensure that every possible route through a given part of the code is executed and tested.

44)What group of teams can do software testing?

When it comes to testing everyone in the world can be involved right from the developer to the project manager to the customer. But below are different types of team groups which can be present in a project.

Isolated test team

Outsource - we can hire external testing resources and do testing for our project.

Inside test team

Developers as testers

QA/QC team.

45)What is the full name of CAST?

Computer Aided Software Testing.

46) What is Capture/Replay Tool?

A test tool that records test input as it is sent to the software under test. The input cases stored can then be used to reproduce the test at a later time. Most commonly applied to GUI test tools.

47)What is Ramp Testing?

Continuously raising an input signal until the system breaks down.

48)What is Application Binary Interface (ABI)?

A specification defining requirements for portability of applications in binary forms across different system platforms and environments.

49) Which of the following tools would be involved in the automation of regression test?

a. Data tester

b. Boundary tester

c. Capture/Playback

d. Output comparator.

Ans. Output comparator

50)An input field takes the year of birth between 1900 and 2004 what are the boundary values for testing this field?

1899,1900,2004,2005