Question 203 - CTFL-2018 discussion

25, 30, and 40 are the test data that show equivalence partitioning to verify if a customer is in their thirties or not. Equivalence partitioning is a technique to divide the input domain into partitions that are expected to behave similarly or produce the same output.Each partition should have at least one representative value as a test case1explains this as follows:

Equivalence Partitioning (or Equivalence Class Partitioning) is an software testing technique that divides the input data of a software unit into partitions of equivalent data from which test cases can be derived. In principle, test cases are designed to cover each partition at least once.

The fundamental concept of Equivalence Partitioning is that you can find more errors in a test case by using a representative value from an equivalence class than by using any other value from the class.

The input domain for the age parameter can be divided into four partitions: less than or equal to zero, between one and 29, between 30 and 39, and greater than or equal to 40. The first and the last partitions are invalid, as they are outside the range of possible ages for human beings. The second and the third partitions are valid, as they are within the range of possible ages for human beings. The test data 25, 30, and 40 represent one value from each partition, covering both valid and invalid cases.

B, C, and D are incorrect answers. B does not include a representative value from the invalid partition greater than or equal to 40. C does not include a representative value from the invalid partition less than or equal to zero. D does not include a representative value from the valid partition between one and 29.