Seven Testing Principles

In this article we  are going to discuss seven principles of testing and brief explanation .

Principle 1:

Testing shows Presence of Defect, but can't prove that there are no defects. Testing reduce the probability of undiscovered defects remaining in the software but, even if no defect are found ,its is not proof of correctness.    
 

Principle 2:

Exhaustive testing is impossible,testing every thing is not feasible. If we take an example where one screen has 15 input fields, each having 5 possible values ,then to test all of valid input value combination need ,  5 ¹⁵ 30,517,578 test!. It is unlikely that the project scale would allow for this test.

Principle 3:

Early Testing, testing activities should start as soon as possible in software  in the software or system development life cycle and should focus on defined objectives, Early testing- such as early test design and review activities - finds early on when they are cheap to find and fix. Once code is written, programmers and testers often run set of tests so they can identify and fix in the software.
 

Principle 4 :

Defect Clustering, In  your opinion, Which operations is most likely to cause your Operating system to fail?

I am sure most of you would have guessed, Opening 10 different application all at the same time. So if you were testing this Operating system you would realize that defects are likely to be found in   multi-tasking and needs to be tested thoroughly which brings us to our next principle Defect Clustering which states that a small number of modules contain most of the defects detected.

Principle 5:

Pesticide Paradox,If the same tests are repeated over and over again , eventually the same test cases will no longer find new bugs. This is the another principle of testing called “Pesticide Paradox "To overcome this, the test cases need to be regularly reviewed & revised , adding new & different test cases to help find more defects. 

Principle 6:

Testing is context dependent, which basically means that the way you test a e-commerce site will be different from the way you test a commercial off the shelf application.

 Principle 7:

Absence of errors - fallacy, if you work extra hard , taking all precautions & make your software product 99% bug free .And the software does not meet the needs & requirements of the clients Absence of Error is a Fallacy i.e. Finding and fixing defects does not help if the system build is unusable and does not fulfill the users needs & requirements.