Black Box Testing - Techniques, Advantages, Disadvantages

Black-box testing alludes to tests that are conducted at the software interface. Black-box tests are used to demonstrate that input is properly accepted and output is correctly produced, and that the integrity of external information is maintained. There is no knowledge of the test object's internal structure. This method of test design is applicable to all levels of software testing: unit, integration, functional testing, system and acceptance. Black box testing tends to be applied during later stages of testing.
Main focus in black box testing is on functionality of the system as a whole. The term ‘behavioral testing’ is also used for black box testing.
To implement black box testing strategy, the tester should go through the requirements specifications and a user should know how the system should behave in response to the particular action.
Black-box testing attempts to find errors in the categories like incorrect or missing functions, interface errors, errors in data structures or external database access, behavior or performance errors, and initialization and termination errors.

Advantages of Black Box Testing
- Tester can be non-technical.
- Used to verify contradictions in actual system and the specifications.
- Test cases can be designed as soon as the functional specifications are complete

Disadvantages of Black Box Testing
- The test inputs needs to be from large sample space.
- It is difficult to identify all possible inputs in limited testing time. So writing test cases is slow and difficult.
- Chances of having unidentified paths during this testing.