21. What is the difference between QA and testing?

The goals of QA are very different from the goals of testing.  The purpose of QA is to prevent errors is the application while the purpose of testing is to find errors. 

22. What is the difference between Quality Control and Quality Assurance?

Quality control (QC) and quality assurance (QA) are closely linked but are very different concepts. While QC evaluates a developed product, the purpose of QA is to ensure that the development process is at a level that makes certain that the system or application will meet the requirements.

23. What is the difference between regression testing and retesting?

Regression testing is performing tests to ensure that modifications to a module or system do not have a negative effect on previous releases.  Retesting is merely running the same testing again.

24. Explain the difference between bug severity and bug priority.

Bug severity refers to the level of impact that the bug has on the application or system while bug priority refers to the level of urgency in the need for a fix.

25. What is the difference between system testing and integration testing?

For system testing, the entire system as a whole is checked, whereas for integration testing, the interaction between the individual modules are tested.

26. Explain the term bug.

A bug is an error found while running a program. Bug fall into two categories: logical and syntax.


<h4><span style=”text-decoration: underline;”><em>Senior Tester Interview Questions</em></span></h4>


27. Explain the difference between functional and structural testing.

Functional testing is considered to be behavioral or black box testing in which the tester verifies that the system or application functions according to specification.  Structural testing on the other hand is based on the code or algorithms and is considered to be white box testing.

28. Define defect density.

Defect density is the total number of defects per lines of code.

29. When is a test considered to be successful?

The purpose of testing is to ensure that the application operates according to the requirements and to discover as many errors and bugs as possible.  This means that tests that cover more functionality and expose more errors are considered to be the most successful.

30. What good bug tracking systems have you used?

This is a simple interview question about your experience with bug tracking.  Provide the system/systems that you are most familiar with if any at all.   It would also be good to provide a comparison of the pros and cons of several if you have experience.

31. In which phase should testing begin – requirements, planning, design, or coding?

Testing should begin as early as the requirements phase.

32. Can you test a program and find 100% of the errors?

It is impossible to fine all errors in an application mostly because there is no way to calculate how many errors exist.  There are many factors involved in such a calculation such as the complexity of the program, the experience of the programmer, and so on.


33. What is the difference between debugging and testing?

The main difference between debugging and testing is that debugging is typically conducted by a developer who also fixes errors during the debugging phase.  Testing on the other hand, finds errors rather than fixes them.  When a tester finds a bug, they usually report it so that a developer can fix it.

34. How should testing be conducted?

Testing should be conducted based on the technical requirements of the application.

35. What is considered to be a good test?

Testing that covers most of the functionality of an object or system is considered to be a good test.

36. What is the difference between top-down and bottom-up testing?

Top-Down testing begins with the system and works its way down to the unit level.  Bottom-up testing checks in the opposite direction, unit level to interface to overall system. Both have value but bottom-up testing usually aids in discovering defects earlier in the development cycle, when the cost to fix errors is lower.

37. Explain how to develop a test plan and a test case.

A test plan consists of a set of test cases. Test cases are developed based on requirement and design documents for the application or system. Once these documents are thoroughly reviewed, the test cases that will make up the test plan can be created.

38. What is the role of quality assurance in a product development lifecycle?

Quality assurance should be involved very early on in the development life cycle so that they can have a better understanding of the system and create sufficient test cases. However, QA should be separated from the development team so that the team is not able to build influence on the QA engineers.

39. What is the average size of executables that you have created?

This is a simple interview question about our experience with executables.  If you know the size of any that you’ve created, simply provide this info.

40. What version of the Oracle are you familiar with?

This is an interview question about experience.  Simply provide the versions of the software that you have experience with.

41. How is an SQL query executed in Oracle 8?

This is an interview question to check your experience with Oracle and you can simply provide the answer “from the command prompt.”  If you do not have Oracle experience, do not pretend and simply state that you have not worked on an Oracle database.

42. Have you performed tests on the front-end and the back-end?

This is an interview question in which you should explain whether you performed testing on the GUI or the server portion of previous applications.

43. What is the most difficult problem you’ve found during testing?

This is a simple interview question in which you should provide an example.

44. What were your testing responsibilities at your previous employer?

This interview question is very likely being asked to verify your knowledge of your resume. Make sure that you know what is on your resume and that it is the truth.

45. What do you like the most about testing?

There are several answers that you can give for this question.  Here are a few examples:

You enjoy the process of hunting down bugs

Your experience and background have been focused on enhancing testing techniques

You like being in the last phase of work before the product reaches the customer

You consider your contribution to the whole development process to be very important.