Black box testing
takes an external perspective of the test object to derive test cases. These tests can be functional or non-functional, though usually functional. The test designer selects valid and invalid input and determines the correct output. 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. The higher the level, and hence the bigger and more complex the box, the more one is forced to use black box testing to simplify. While this method can uncover unimplemented parts of the specification, one cannot be sure that all existent paths are tested.
- Compare with white box testing.
Test design techniques
Typical black box test design techniques include:
Functional testing devices like power supplies, amplifiers, and many other simple function electrical devices is common in the electronics industry. Automated functional testing of specified characteristics is used for production testing, and part of design validation.