What is equivalence partitioning in software testing?

Equivalence partitioning is a testing technique used to reduce the number of test cases by categorizing inputs into equivalent classes. The core idea is to identify a set of possible inputs where the software is expected to behave the same way. By selecting representative values from these groups of inputs, testers can efficiently verify that the software behaves correctly for a wide range of scenarios without needing to test every single input.

For example, if an application accepts a number input within a specific range, instead of testing every integer within that range, a tester might select one value from each partition (e.g., a value below the minimum, a value within the range, and a value above the maximum). This approach not only makes testing more manageable but also ensures comprehensive coverage of the input space.

This method does not involve a one-time execution of the software, testing with massive datasets, or focusing specifically on graphical interface bugs, as those do not utilize the strategy of representative sampling from classes of inputs.