Which assertion regarding equivalence partitioning is correct?

Equivalence partitioning is a testing technique used to derive test cases from the input domain of software applications. The primary aim is to group equivalent input values that are expected to produce similar results, effectively reducing the total number of test cases while maintaining adequate coverage.

When we say that equivalence partitioning creates categories for input values, it means that inputs can be organized into classes or partitions where each class represents a set of values considered to be equivalent for the purpose of testing. This categorization allows testers to select one representative value from each class to validate the expected behavior of the application, thus enhancing efficiency in the testing process.

Other options do not accurately reflect the nature of equivalence partitioning. For instance, not requiring discrete values in its application misrepresents the technique, as it fundamentally relies on identifiable input groups. Focusing solely on boundary values instead pertains more closely to boundary value analysis than to equivalence partitioning. Lastly, the idea that it relies solely on failed test cases misrepresents the purpose of this technique, which seeks to identify valid and invalid inputs, not just scenarios that result in failures.

Thus, the assertion regarding creating categories for input values accurately reflects the essence of equivalence partitioning and its application in software testing.