Laws of Manual Testing
Bug Rate Principle
Decreasing bug rates validate effective testing.
Principle of Speed
Manual testing slows development, to speed up quality.
The Teacher Paradox
If someone is selling a philosophy of manual testing — they are wrong.
Test Count Paradox
Test counts are not correlated with value, only cost.
Law of Test Passes
The best testers continually test.
Law Of Timing
Testing should start when it makes sense, not always early.
Law Of Coverage
Estimates of code or test coverage are wrong.
Law of Smoke
Always more fire where there is smoke.
Testers be Testing Principal
Teachers and preachers. aren’t testers, beware.
Bug and Coverage Paradox
Non-testers only care about ship-blockers.
Priority principal
Test prioritization should be greatly deprioritized.
Myth of the Right Way To Test
Testing is all contextual and still an art, not a science.
Waldo Paradox
The bugs are where you haven’t looked yet.
Paradox of Quality Ownership
Testers will still be held accountable for quality, and they should be.
Law of Time
All software will break given enough time.
Insurance Principal
Testing is insurance and due diligence.
Law of Quantification
Perfectly repeatable / documented test cases are essential.
Paradox of More Testing
Diminishing returns means you always test more than you should.
Agile Myth
Agile just means ‘less waterfall’.
Law of Agile Testing
Simply test the newest stuff, and the most risky.
TDD Myth
No one does TDD.
Law of Learning
Most learning by testers should be about the world, the users and the context — not the application.
Myth of Formalization
Cucumber and User Stories are not formal methods.
Law of AI
The more a tester or vendor mentions AI, the less likely they know what it is.
Myth of Learning
If someone is ‘learning about the app’, they are just bored with testing in general.
Law of Testing Simplicity
Beware of testers redefining words, they are poor testers.
User Paradox
You are not the user.
Ratio Principle
Developer-tester ratios should be proportional to the software’s need for accuracy multiplied by its behavioral variability.
Test Marketing Paradox
The usefulness of a tool is inversely proportional to the marketing claims and price.
Tester Efficacy Paradox:
Testers add bugs, not software quality.
Reporting Principle
Other than 100%, percentages aren’t useful.
— Jason Arbon, TestNerd
