Black box testing: Meaning (information, definition, explanation, facts)

Black box testing or functional testing is used in computer programming, software engineering and software testing to check that the outputs of a program, given certain inputs, conform to the functional specification of the program.

The term black box indicates that the internal implementation of the program being executed is not examined by the tester. For this reason black box testing is not normally carried out by the programmer. In most real-world engineering firms, one group does design work while a seperate group does the testing.

A complementary technique, white box testing or structural testing, uses information about the structure of the program to check that it performs correctly.

A technique in black box testing is equivalence partitioning. Equivalence partitioning is designed to minimize the number of test cases by dividing tests into such a way that the system is expected to act the same way for all tests of each equivalence partition. Test inputs would be selected from each partition.

Equivalence partitions are designed so that every possible input belongs to one and only one equivalence partition.

Disadvantages to Equivalence partitions

• Doesn't test every input
• No guidelines for choosing inputs
• Heuristic-based