7 Principles Of Testing

Front 1

Testing shows presence of defects (P1)

Back 1

(P1) Testing can show the presence of defects but can not show that there are now defects. Testing reduces the probability but does not prove correctness.

Front 2

Exhaustive Testing is Impossible (P2)

Back 2

(P2) Testing everything is not feasible and priorities should be used to focus testing efforts

Front 3

Early Testing (P3)

Back 3

P3 To find defects early testing activities shall be started as early as possible and shall be focused on defined objectives.

Front 4

Defect Clustering P4

Back 4

P4 Testing effort shall be proportional focused to the expected and later observed defect density of modules.

Front 5

Pesticide Paradox P5

Back 5

P5 If the same tests are repeated over and over again, eventually the same set of test cases will no longer find new defects.

To combat this test cases need to regular reviewed and revised, and new and different tests need to be written.

Front 6

Testing is context dependent P6

Back 6

P6 Testing is done differently in different contexts. Games are tested differently than e-commerce software

Front 7

Absence of errors fallacy P7

Back 7

P7 Fixing and finding defects does not help if the system is unusable and does not fulfill the users needs and exceptions.