Equivalence class testing is a software testing technique that divides input values into valid and invalid categories called equivalence classes. Representative values are selected from each class as test data. This technique reduces the number of test cases needed while maintaining thorough coverage. An example divides numbers into classes of valid 2-3 digit numbers and invalid single digit numbers to test a program's valid and invalid number handling. There are different types of equivalence class testing that vary in robustness. The technique helps reduce testing time and cases but requires expertise to define classes and may not test all boundary conditions.

1. EQUIVALENCE
CLASS TESTING
By: Neha Jha
B.Tech(CSE) 5th Semester
1

2. Black Box Testing
• It is a software testing method in which the internal
structure/design/implementation of the item being tested is not known to
the tester.
Equivalence Class Testing 2

3. Equivalence Class Testing
• It is a software test design technique that involves dividing input values into
valid and invalid partitions and selecting representative values from each
partition as test data.
Equivalence Class Testing 3

4. Equivalence Class Testing
The use of equivalence classes is appropriate in situations like:
• When exhaustive testing is desired.
• When there is a strong need to avoid redundancy.
Equivalence Class Testing 4

5. Example
• Consider a software application, which takes not less than two digit number and not
more than 3 digit number, for its execution.
Inputs to test are:1,2,3,.................1498,1499,1500.
• 4 classes are formed and are accordingly the inputs are divided into category of
valid and invalid inputs.
Equivalence Class Testing 5

6. Example
• Valid input : Number 121 is used from the class “3 digit numbers" i.e. valid
input It is expected by the software application, to function properly, on
using number 121, and if it does then the software is functioning
appropriately.
• Invalid input : Number 7 is used from the class "single digit numbers", i.e.
invalid input. It is expected by the software application, to generate error, on
using number 7, and if it does then the software is functioning appropriately.
Equivalence Class Testing 6

7. Equivalence Class Testing
Types of equivalence class testing:
1) Weak Normal Equivalence Class Testing.
2) Strong Normal Equivalence Class Testing.
3) Weak Robust Equivalence Class Testing.
4) Strong Robust Equivalence Class Testing.
Equivalence Class Testing 7

8. Advantages and Disadvantages
Advantages:
• Equivalence class testing helps reduce the number of test cases without
compromising the test coverage.
• Reduces the overall test execution time as it minimizes the set of test data.
Disadvantages:
• It does not consider the conditions for boundary value.
• The identification of equivalence classes relies heavily on the expertise of testers.
Equivalence Class Testing 8

9. Thank You!
9