Software Testing Quality Control & Assurance 5 — Questions and Answers
Question 1: Which principle states that testing can reveal the presence of defects but cannot prove their absence?
- Pesticide paradox
- Exhaustive testing is impossible
- Testing shows the presence, not absence, of defects (Correct answer)
- Defect clustering
Correct answer: Testing shows the presence, not absence, of defects
This fundamental testing principle, articulated by Dijkstra, means that even a comprehensive test suite passing does not guarantee the software is defect-free.
Question 2: A QA team discovers that running the same set of regression tests over many cycles no longer finds new defects. This phenomenon is called:
- Test saturation
- The pesticide paradox (Correct answer)
- Defect clustering
- Confirmation bias
Correct answer: The pesticide paradox
The pesticide paradox describes how repeatedly running the same tests eventually stops finding new bugs because the software adapts and test cases become ineffective over time.
Question 3: In an Agile QA context, what is the primary purpose of a Definition of Done (DoD)?
- To document all known defects in a sprint
- To establish shared quality criteria that must be met before a feature is considered complete (Correct answer)
- To assign testing tasks to specific team members
- To define the sprint length and velocity
Correct answer: To establish shared quality criteria that must be met before a feature is considered complete
The Definition of Done establishes agreed-upon quality criteria (tests passed, code reviewed, documented, etc.) that must be satisfied before work is considered complete.
Question 4: Which type of non-functional testing evaluates how a system behaves under varying user loads to identify the maximum operational capacity?
- Stress testing
- Load testing (Correct answer)
- Spike testing
- Soak testing
Correct answer: Load testing
Load testing gradually increases user load to determine the system's capacity and performance at expected and peak traffic levels.
Question 5: A quality audit reveals that developers are skipping unit tests to meet sprint deadlines. The QA manager's BEST response is to:
- Accept the risk and document it in the test summary report
- Recommend adding unit testing to the Definition of Done and escalate to management (Correct answer)
- Perform additional manual testing to compensate
- Reduce the sprint scope to allow time for testing
Correct answer: Recommend adding unit testing to the Definition of Done and escalate to management
Embedding unit testing in the Definition of Done makes it a non-negotiable quality gate, and escalating ensures management enforces the standard consistently.
Question 6: Which software quality characteristic from the ISO/IEC 25010 model refers to the degree to which a product can be used by people with a wide range of abilities?
- Usability
- Accessibility (Correct answer)
- Portability
- Reliability
Correct answer: Accessibility
Accessibility is a sub-characteristic of usability in ISO/IEC 25010 that measures how well the product can be used by people with disabilities or diverse capabilities.
Question 7: When should quality assurance activities ideally begin in the software development lifecycle?
- After coding is complete and the build is available for testing
- During the requirements phase, as early as possible (Correct answer)
- When the first defect is reported by a tester
- After the system integration phase
Correct answer: During the requirements phase, as early as possible
QA should start at the requirements phase because defects introduced early are exponentially cheaper to fix than those found later, following the 'shift-left' principle.
Software Testing Quality Control & Assurance 5
Which principle states that testing can reveal the presence of defects but cannot prove their absence?