Black Box Testing: Also called as Behavioural Testing. It is a Function-based testing, which focuses on testing the functional requirements. The test cases are designed with a view point that for a particular set of input conditions, you will get a particular set of output values. It is mostly being done at later stages of testing.
Black Box Testing Methods: Following are the various ways in which Black Box testing is carried out:
1. Graph- Based Testing: Identifying the objects and relationships between them. And then testing whether the relationship behave as expected or not. Graphs are used to prepare the test cases, in which: objects are represented as Nodes and relationships as Links.
2. Eqivalence Class Testing: A set of input domain is partitioned into different classes. And selecting the test data from each class. The equivalence class represents the valid and invalid states for input conditions.
3. Boundary Value Testing: It is carried out by selecting the test cases that exercises bounding values. For eg, if a test case accepts values with the range (a to d), then testing the behaviour at ‘a’ and ‘d’.
4. Comparison Testing: Also called back-to-back testing. In this method, different software teams build a product using the same specification but different technologies and methodologies. After that all the versions are tested and their ouput is compared. Its not a full proof testing method since even if they all give the same results, if one is incorrect all of them will be incorrect.
