Black box testing is a technique of software testing which emphasis only on providing input and collecting output without knowing the internal knowledge or code of software program.
It tests all functional and non functional requirements and verifies whether it is meeting user expectations or not. Black box testing is a process of derive output without reference to its internal structure of program.
In black box testing won’t concern to identify all logical paths, develop test case. No need to have detailed technical knowledge of software to testers.
It is also called as functional testing or behavioral testing.
Black box testing used to discover following errors
– Functional or behavior errors
– Missing functionality
– Component interface (communication)error
– Database error
– Performance issues
A tester, without knowledge of the internal structures of any calculator, tests the all functionality like addition, subtraction, multiplication and division etc.; by providing inputs and verifying the outputs against the expected outcome.
Advantages of black box testing -:
1. More effective in larger unit of code than others
2. Tester can be non technical
3. Used to verify all functional specifications
4. Testing done from user point of view
Disadvantages of black box testing –:
1. Chances of having unknown paths during testing
2. Chances of having repetition
3. Difficult to find tricky inputs if test cases are not designed
4. Difficult to identify all possible inputs in limited testing time
Methods of black box testing -:
A] Equivalence partitioning
B] Boundary value analysis
C] Cause effect graph
D] Error guessing