Black box testing tests the functionality of software without knowledge of its internal structure or design. It is performed by testers and clients to test the software from an end user's perspective. There are various techniques used in black box testing including equivalence partitioning, boundary value analysis, and error guessing.

1. Black box testing

2. Objective What is Black box testing Who does it Techniques of black box testing

3. What is black box testing? Knows only what the software is supposed to do Doesn’t know how it operates inside Why named as black box testing? You cannot see inside the box What & Why the name

4. Who, When & Why Who does black box testing? Testers Business Analysis Clients When you do? Once the functionality is developed Why not by developers? Very difficult to break one’s own code To test the software from end-user perspective Fresh eyes always help

5. Calc Example

6. Test design techniques Equivalence Partitioning To reduce the number of test data To select the right test cases to cover all possible scenarios Ex: parameter “month” of a date now divided into 3 partitions (invalid partition1, valid partition, invalid partition2) Test Data : 1 or 2 from each partition. In this ex. - -3, 4, 15

7. If software can operate on the edge of its capabilities, it will certainly operate well under normal conditions. Example – possible values for the range 3-10 are 2,3,4,9,10,11 Back to month example: Possible values are : 0, 1, 2, 11, 12, 13 Partition U BVA : -3,0,1,2,4,11,12,13,15 Boundary Value Analysis

8. Error Guessing Tester guesses from his /her experience on the error-prone area and concentrates around that area . Example : When the bike stops, first thing you do is – check the petrol. You probably wont go to mechanic or read the manual or check the spark plug You know from your experience or usage that petrol could be over.

9. Same example

10. Questions?