The black box is a testing type where the tester doesn’t know the internal design of the component or system which undergoes testing. So if we don’t know the internal design, how do we ensure that our test cases can still find defects and provide excellent coverage? It is where Black Box testing techniques come into the picture. These are scientific and time tested techniques that will help us get maximum coverage in minimum test cases.
Black-Box Technique and its Common Characteristics
Before we dive into actual techniques, let’s discuss some of the common characteristics of Black box techniques.
Test cases (including test conditions and test data) derive from Requirements, User Stories, User cases, and user specifications.
Test cases are used to detect gaps between the requirements and the actual implementation.
Measurement of Coverage happens in terms of requirements and the test cases written for these requirements.
Black box testing techniques apply to all test levels (Component Testing, Component Integration testing, System Testing, and Unit Testing).
As you can see, we are not looking at design and code coverage (Why ? Because it’s a black box ! ).