Equivalence partitioning in Testing Fundamentals - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is equivalence partitioning in software testing?

Equivalence partitioning is a testing technique that divides input data into groups where test cases from each group are expected to behave the same. This helps reduce the number of test cases while still covering all scenarios.

beginner

Why do testers use equivalence partitioning?

Testers use equivalence partitioning to save time and effort by testing one value from each group instead of all possible inputs, assuming all values in a group behave similarly.

beginner

Give an example of equivalence partitions for an input field that accepts ages from 18 to 60.

The partitions could be: invalid low (below 18), valid (18 to 60), and invalid high (above 60). Testing one value from each partition is enough to check behavior.

intermediate

How does equivalence partitioning relate to boundary value analysis?

Equivalence partitioning groups inputs, while boundary value analysis focuses on testing the edges of those groups because errors often happen at boundaries.

intermediate

What is a common mistake when applying equivalence partitioning?

A common mistake is not identifying all partitions correctly or assuming all values in a partition behave the same without verifying, which can miss defects.

What does equivalence partitioning help testers do?

A Reduce the number of test cases by grouping inputs

B Test only the boundary values

C Write code faster

D Automate all tests

Equivalence partitioning groups inputs to reduce test cases while covering all scenarios.

Which of these is an example of an equivalence partition for a password length of 8 to 12 characters?

A Passwords of length 7, 8, and 13

B Passwords of length 5, 6, and 7

C Passwords of length 8, 10, and 12

D Passwords of length 13, 14, and 15

Lengths 8, 10, and 12 are valid inputs within the partition; 7 and 13 are outside.

Which is NOT a benefit of equivalence partitioning?

A Improves test coverage

B Ensures all code paths are tested

C Helps find defects efficiently

D Reduces test effort

Equivalence partitioning reduces test cases but does not guarantee all code paths are tested.

If an input accepts numbers 1 to 100, which is a valid equivalence partition?

A 1 to 100

B 0 to 50

C 101 to 200

D All negative numbers

1 to 100 is the valid input partition; others are invalid partitions.

What should you test from each equivalence partition?

A Only the smallest value

B All values

C Only the largest value

D At least one representative value

Testing one representative value from each partition is enough to check behavior.

Explain equivalence partitioning and why it is useful in software testing.

Think about how you can test fewer inputs but still cover all cases.

Describe how you would create equivalence partitions for a form field that accepts ages between 18 and 60.

Divide inputs into valid and invalid groups.

Practice

1. What is the main purpose of equivalence partitioning in software testing?

easy

A. To test every possible input value individually

B. To write code for automated testing

C. To divide input data into groups where test cases can be reduced

D. To check the user interface design

Solution

1. Step 1: Understand equivalence partitioning concept

   Equivalence partitioning divides input data into groups where all inputs in a group behave similarly.

2. Step 2: Identify the main goal

   The goal is to reduce the number of test cases by testing one value from each group instead of all values.

3. Final Answer:

   To divide input data into groups where test cases can be reduced -> Option C

4. Quick Check:

   Equivalence partitioning = reduce test cases [OK]

Hint: Group inputs to test fewer cases efficiently [OK]

Common Mistakes:

• Thinking it tests every input value
• Confusing with UI testing
• Assuming it is about coding tests

2. Which of the following is the correct way to apply equivalence partitioning for an input field that accepts ages from 18 to 60?

easy

A. Test ages 17, 18, 30, 60, 61

B. Test ages 18, 30, 60 only

C. Test ages 0, 18, 60, 100

D. Test ages 18, 19, 20, 21

Solution

1. Step 1: Identify equivalence partitions

   Partitions are: below valid range (<18), valid range (18-60), above valid range (>60).

2. Step 2: Select test values from each partition

   Choose one value from each: 17 (below), 18 and 60 (edges of valid), 30 (inside valid), 61 (above).

3. Final Answer:

   Test ages 17, 18, 30, 60, 61 -> Option A

4. Quick Check:

   Test one from each partition [OK]

Hint: Pick one value from each input group including edges [OK]

Common Mistakes:

• Testing only valid values
• Ignoring boundary values
• Testing too many values inside one partition

3. Given the input field accepts numbers 1 to 100, which test inputs represent valid equivalence partitions?

medium

A. [50, 75, 100]

B. [0, 1, 50, 100, 101]

C. [-1, 0, 101]

D. [1, 50, 100]

Solution

1. Step 1: Define partitions

   Partitions are: below valid (<1), valid (1-100), above valid (>100).

2. Step 2: Check which inputs cover all partitions

   [0, 1, 50, 100, 101] includes 0 (below), 1 and 100 (edges valid), 50 (inside valid), 101 (above).

3. Final Answer:

   [0, 1, 50, 100, 101] -> Option B

4. Quick Check:

   Inputs cover all partitions [OK]

Hint: Include below, inside, and above range values [OK]

Common Mistakes:

• Missing values outside valid range
• Testing only inside range
• Ignoring boundary values

4. You have a form field that accepts a password length from 8 to 12 characters. Which test set correctly applies equivalence partitioning and fixes the error in this set: [7, 8, 10, 12, 13]?

medium

A. [7, 8, 10, 12, 13]

B. [8, 10, 12]

C. [7, 8, 12, 13]

D. [6, 8, 10, 12, 14]

Solution

1. Step 1: Identify partitions and errors

   Partitions: below valid (<8), valid (8-12), above valid (>12). The original set misses some below and above values.

2. Step 2: Fix test set to cover all partitions

   [6, 8, 10, 12, 14] adds 6 (below), 14 (above), and includes valid 8, 10, 12, covering all partitions correctly.

3. Final Answer:

   [6, 8, 10, 12, 14] -> Option D

4. Quick Check:

   Test covers below, valid, and above partitions [OK]

Hint: Include clear below and above boundary values [OK]

Common Mistakes:

• Missing values outside valid range
• Not testing boundary values
• Using only valid inputs

5. A software accepts input scores from 0 to 100. Using equivalence partitioning, which test inputs should you select to cover all partitions if the input is extended to accept decimal values between 0.0 and 100.0?

hard

A. [ -1, 0.0, 50.5, 100.0, 101 ]

B. [ 0, 25, 50, 75, 100 ]

C. [ 0.0, 50.0, 100.0 ]

D. [ -0.1, 0, 50, 100, 100.1 ]

Solution

1. Step 1: Define partitions including decimals

   Partitions: below valid (<0.0), valid (0.0 to 100.0), above valid (>100.0). Decimals allowed inside valid range.

2. Step 2: Choose test inputs covering all partitions

   [ -1, 0.0, 50.5, 100.0, 101 ] includes -1 (below), 0.0 (valid edge), 50.5 (valid decimal), 100.0 (valid edge), 101 (above).

3. Final Answer:

   [ -1, 0.0, 50.5, 100.0, 101 ] -> Option A

4. Quick Check:

   Test inputs cover all partitions including decimals [OK]

Hint: Include decimals and boundary values in partitions [OK]

Common Mistakes:

• Ignoring decimal values inside valid range
• Missing values outside valid range
• Testing only integers