Learner can name the seven ISTQB testing principles and apply each to a realistic situation.
Seven principles that guide every tester
Seven principles that guide every tester
ISTQB defines seven principles that apply to almost every testing situation. Understanding them helps you make better decisions about where to focus effort.
Principle 1 — Testing shows the presence, not absence, of defects. Tests can reveal bugs, but a clean test run never proves a system is defect-free. Principle 2 — Exhaustive testing is impossible. You cannot test every combination of inputs and states, so testers use risk and priority to select what to cover. Principle 3 — Early testing saves time and money (shift-left). Finding a defect in requirements costs far less than finding it in production. Principle 4 — Defects cluster. A small number of modules or features typically contain the majority of defects — focus your effort there.
Principle 5 — The pesticide paradox (tests wear out). If you run the same tests over and over, they stop finding new bugs. You must regularly review and update your test cases to keep them effective. Principle 6 — Testing is context-dependent. The right approach for a medical device is very different from a gaming app — always tailor your strategy to the project. Principle 7 — Absence-of-defects fallacy. A system with no reported defects can still fail users if it does not meet their actual needs. Passing tests do not equal user satisfaction.
Lesson notes
Seven principles that guide every tester
ISTQB defines seven principles that apply to almost every testing situation. Understanding them helps you make better decisions about where to focus effort.
Principle 1 — Testing shows the presence, not absence, of defects. Tests can reveal bugs, but a clean test run never proves a system is defect-free. Principle 2 — Exhaustive testing is impossible. You cannot test every combination of inputs and states, so testers use risk and priority to select what to cover. Principle 3 — Early testing saves time and money (shift-left). Finding a defect in requirements costs far less than finding it in production. Principle 4 — Defects cluster. A small number of modules or features typically contain the majority of defects — focus your effort there.
Principle 5 — The pesticide paradox (tests wear out). If you run the same tests over and over, they stop finding new bugs. You must regularly review and update your test cases to keep them effective. Principle 6 — Testing is context-dependent. The right approach for a medical device is very different from a gaming app — always tailor your strategy to the project. Principle 7 — Absence-of-defects fallacy. A system with no reported defects can still fail users if it does not meet their actual needs. Passing tests do not equal user satisfaction.