In foundation level syllabus you will find the main basic principles of testing, which of the following sentences describes one of these basic principles?

In foundation level syllabus you will find the main basic principles of testing, which of the following sentences describes one of these basic principles?
A . Complete testing of software is attainable if you have enough resources and test tools
B . For a software system, it is not possible under normal conditions, to test all input and output combinations.
C . A goal of testing is to show that the software is defect free
D . With automated testing you can make statements with more confidence about the quality of a product than with manual testing.

View Answer

Answer: B

Explanation:

One of the basic principles of testing is that for a software system, it is not possible under normal conditions to test all input and output combinations because they are too many and too complex to cover within a reasonable time and budget. Therefore, testers have to select a subset of inputs and outputs that are representative and relevant for testing based on criteria such as requirements, risks, priorities, etc. This principle implies that testing cannot prove that a software system is defect-free or has a certain level of quality because there might be some untested inputs or outputs that could reveal defects or failures. Testing can only provide information about the quality and risk level of a software system based on the observed behavior and results under certain conditions and assumptions. You can find more information about the basic principles of testing in A Study Guide to the ISTQB® Foundation Level 2018 Syllabus, Chapter 11.