QA Fundamentals Middle interview questions and answers

75 questions for a QA Fundamentals (Middle) interview - with correct answers, explanations and links to the docs.

Take this quiz
  1. 1.When is decision table testing most useful?
  2. 2.A rule has 3 independent yes/no conditions. How many columns does a full decision table have?
  3. 3.When is state transition testing a good choice?
  4. 4.In state transition testing, why test invalid transitions?
  5. 5.What problem does pairwise (all-pairs) testing solve?
  6. 6.What is the main limitation of pairwise testing?
  7. 7.What is use case testing?
  8. 8.What is error guessing?
  9. 9.What does statement coverage measure?
  10. 10.Why is branch coverage stronger than statement coverage?
  11. 11.Why is high code coverage alone not proof of good tests?
  12. 12.What is risk-based testing?
  13. 13.Which two factors usually define the level of a product risk?
  14. 14.What is the difference between a test plan and a test strategy?
  15. 15.How can a tester estimate testing effort?
  16. 16.What is the main idea of the agile testing quadrants?
  17. 17.What does BDD add to testing?
  18. 18.What does this Gherkin scenario describe?
  19. 19.What is a common mistake when writing Gherkin scenarios?
  20. 20.What is TDD?
  21. 21.How does a test double such as a mock or stub help?
  22. 22.What is a risk of mocking too much?
  23. 23.What does contract testing check?
  24. 24.What is a common cause of flaky UI tests?
  25. 25.How should a team handle a flaky test that can't be fixed today?
  26. 26.Why should tests not depend on each other's data?
  27. 27.How can a regression suite stay manageable as the product grows?
  28. 28.What is test impact analysis?
  29. 29.What does 'defect leakage' measure?
  30. 30.What is defect removal efficiency (DRE)?
  31. 31.Why is 'number of test cases executed' a weak quality metric?
  32. 32.What is root cause analysis for a defect?
  33. 33.What is session-based test management?
  34. 34.What is a test charter?
  35. 35.What are test heuristics such as SFDPOT?
  36. 36.What is mutation testing?
  37. 37.Why test the API directly instead of only through the UI?
  38. 38.An API PUT request is sent twice with the same body. What should a tester expect?
  39. 39.What should be checked in an API error response besides the status code?
  40. 40.Why should a tester check data in the database after a UI action?
  41. 41.How do logs help when testing?
  42. 42.What is a feature flag, and what does it mean for testing?
  43. 43.What is the difference between load, stress, spike and soak tests?
  44. 44.Why are percentiles like p95 preferred over the average response time?
  45. 45.What should be agreed before running a performance test?
  46. 46.What is a typical check for broken access control?
  47. 47.Which input can reveal an XSS problem?
  48. 48.What is special about testing mobile apps compared to web?
  49. 49.How should a tester choose browsers and devices to test on?
  50. 50.What are common accessibility checks a tester can do without special tools?
  51. 51.What is usability heuristic evaluation?
  52. 52.What is the role of a test summary report?
  53. 53.What is a defect triage meeting for?
  54. 54.A developer marks your bug 'works as designed'. What is a good next step?
  55. 55.Why do testers and developers pair on testing?
  56. 56.What is shift-right testing?
  57. 57.What is a canary release?
  58. 58.Why should test environments be reproducible?
  59. 59.What is service virtualization used for?
  60. 60.Why shouldn't production personal data be copied into test environments as is?
  61. 61.What does 'testability' mean for a feature?
  62. 62.How do the terms 'test condition' and 'test case' differ?
  63. 63.What is the purpose of a requirements review checklist?
  64. 64.Which phrase in a requirement is a red flag for testability?
  65. 65.What does 'equivalence class' mean for a dropdown of countries?
  66. 66.Why test with special characters and different languages in text fields?
  67. 67.What is the main goal of a smoke suite in CI?
  68. 68.How do quality gates in a pipeline help?
  69. 69.Why are tests at many levels needed instead of only end-to-end tests?
  70. 70.What does the 'testing trophy' emphasize compared to the pyramid?
  71. 71.What is a good practice for test case names or titles?
  72. 72.When should a tester stop exploratory testing of a feature?
  73. 73.Why should automated tests have clear failure messages?
  74. 74.What is a 'definition of ready' for a story from a tester's point of view?
  75. 75.What is a bug bash?