Black Box Testing

Black Box Testing

Black box testing is a testing technique in which the system or application is treated is a black box mean that the system is tested with a set of specific inputs and a specific out put is expected from it if the actual out put of the given input is the as expected then the test is considered is passed other wise the test is consider is fail.
A simple diagram of how black box testing is performed is shown below

Black box testing also known is behavioral or functional testing it is called black box because tester don't need to know the internal structure of the system, how the system is mapping inputs to certain outputs, which data structure is used all these details are of no relevant to the tester they just provide inputs and expect a specific output.

Example

If we are testing a calculator like application then black box testing would be giving for example inputs values "5 + 10" and expecting that it will result in generating "15" is an outputs if the application produce so the test is passed other wise test is fail.

Pros of Black Box testing

• It's easy and inexpensive because the tester need not to be an expert
• A major functionality if not working could be determined easily
• Incorrect or undesirable result can be cached easily
• Test cases can easily be prepared from the specifications of the system

Cons of Black box testing

• System can't be tested with all set of inputs
• Is cases are prepared from the specification of the system if there is no specification then it would be difficult to generate test cases

Techniques of black box testing

equivalence partitioning

equivalence partitioning is a black box testing technique in which the input values are divided into valid and invalid partitions and a representative data input is selected from both partition for the testing.

Boundary value analysis

It's also a black box testing technique in which the test data is prepared from inside and outside of the boundary and then the system is tested with these boundary inputs if the test pass for the boundary values then the system is assumed to produce the correct result for all the inputs that lies within that boundary, boundary values analysis is more appropriate and is considered best method for identifying defects at the because most of the defects lies at boundary of the application.

Smoke testing

is also a high level abstraction black box testing technique in which the major functionality of the software is tested if its work then then the system is further tested otherwise the system is not tested further.