Equivalence Class Testing Technique Training

Agenda

Introduction
Technique
Examples
Applicability and Limitations
Summary
Practice
References

Introduction

What is equivalence class testing? What is it used for?

Equivalence class testing

Introduction: Situation

We are writing a module for a human resources system

Introduction: Coverage

Should we test the module for the following ages: 0,

Introduction: Solution 1

If (applicantAge == 0) hireStatus="NO";
If (applicantAge == 1) hireStatus="NO";
…
If

Introduction: Let’s believe

Introduction: Solution 2

If (applicantAge >= 0 && applicantAge <=16)
hireStatus="NO";
If (applicantAge

Introduction: Benefits

Using the equivalence class approach, we have reduced the number

Introduction: Definition

An equivalence class consists of a set of data that

Introduction: Assumptions

Specifically, we would expect that:
If one test case in an

Introduction: Solution 3

If (applicantAge >= 0 && applicantAge <=16)
hireStatus="NO";
If (applicantAge

Introduction: Ready?

Now, are we ready to begin testing?
Probably not.
What

Technique

Technique: Steps

1. Identify the equivalence classes.
2. Create a test case

Technique: Continuous

Continuous equivalence classes
For a valid input we might choose $1,342/month.

Technique: Discrete

Discrete equivalence classes
For a valid input we might choose 2

Technique: Array

Single selection equivalence classes
For a valid input we must

Technique: Array

Multiple selection equivalence class
While the rule says choose one test

Technique: Contradictions

But, if this were a list of the fifty states,

Technique: Combination

Rarely we will have the time to create individual tests

Technique: All invalid

A test case of invalid data values.

If the system

Technique: One invalid

In many cases, errors in one input field may

Technique: Varying values

For additional warm and fuzzy feelings, the inputs (both

Technique: Tips

Another approach to using equivalence classes is to examine the

Examples

Examples: 1

No invalid choices.
It reduces the number of test cases the

Examples: 2

Input to this field can be between one and four

Examples: 3

The valid symbols are {A, AA, AABC, AAC, ..., ZOLT,

Examples: 4

Rarely will we create separate sets of test cases for

Applicability and Limitations

Applicability and Limitations

Equivalence class testing can significantly reduce the number of

Applicability and Limitations

Very often your designers and programmers use GUI design

Summary

Summary

Equivalence class testing is a technique used to reduce the number

Practice

Practice

ZIP Code – five numeric digits.
Last Name – one through fifteen

Practice: Answers 1

ZIP Code – five numeric digits.

Length
Valid: 5
Invalid: 3; 20

Characters
Valid:

Practice: Answers 2

Last Name – one through fifteen characters (including alphabetic

Practice: Answers 3

User ID – eight characters at least two of

Practice: Answers 4

Student ID – eight characters. The first two represent

Practice: Answers 5

References