Mr; Mrs.; Ms; any other input is the correct list of the equivalence classes of the input values for this field. 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 case3 explains 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 this field can be divided into four partitions: Mr, Mrs., Ms, and any other input. The first three partitions are valid, as they are the only acceptable values for this field. The last partition is invalid, as it includes any value that is not Mr, Mrs., or Ms, such as Dr, Prof, Miss, etc.
