Test estimation techniques in Testing Fundamentals - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to calculate the total test effort by multiplying the number of test cases by the average time per test case.

Testing Fundamentals

total_effort = num_test_cases [1] avg_time_per_test

Drag options to blanks, or click blank then click option'

A+

B/

C-

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of * results in incorrect total effort.

We multiply the number of test cases by the average time per test case to get the total effort.

2fill in blank

medium

Complete the code to estimate the number of test cases using the function points and a productivity factor.

Testing Fundamentals

estimated_tests = function_points [1] productivity_factor

Drag options to blanks, or click blank then click option'

A*

B-

C+

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using division or addition instead of multiplication.

Multiplying function points by productivity factor estimates the number of test cases.

3fill in blank

hard

Fix the error in the code to calculate the average time per test case by dividing total time by number of test cases.

Testing Fundamentals

avg_time = total_time [1] num_test_cases

Drag options to blanks, or click blank then click option'

A+

B*

C/

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using multiplication or addition instead of division.

Average time is total time divided by number of test cases.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps each test type to its estimated effort if the effort is greater than 5 hours.

Testing Fundamentals

effort_estimates = {test_type: [1] for test_type, [2] in test_data.items() if [1] > 5}

Drag options to blanks, or click blank then click option'

Aeffort

Btime

Ccount

Dduration

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names for value in comprehension and condition.

The dictionary maps test_type to effort, iterating over test_data items with effort as value.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps each test case ID (uppercased) to its duration if the duration is greater than 2 hours.

Testing Fundamentals

filtered_tests = {{ [1]: [2] for test_id, [3] in tests.items() if [2] > 2 }}

Drag options to blanks, or click blank then click option'

Atest_id.upper()

Bduration

Dtest_id

Attempts:

3 left

💡 Hint

Common Mistakes

Using test_id instead of uppercased test_id as key.

Mismatching variable names.

The comprehension uses uppercased test_id as key and duration as value, filtering by duration > 2.

Practice

1. Which of the following best describes the purpose of test estimation in software testing?

easy

A. To predict the time and effort needed for testing activities

B. To write test cases for all features

C. To find all bugs in the software

D. To automate all test scripts

Solution

1. Step 1: Understand the role of test estimation

   Test estimation is used to predict how much time and effort testing will take.

2. Step 2: Compare options to the definition

   Only To predict the time and effort needed for testing activities matches this purpose; others describe different testing tasks.

3. Final Answer:

   To predict the time and effort needed for testing activities -> Option A

4. Quick Check:

   Test estimation = Predict effort [OK]

Hint: Test estimation predicts effort and time needed [OK]

Common Mistakes:

• Confusing estimation with test case design
• Thinking estimation finds bugs
• Mixing estimation with automation tasks

2. Which of the following is the correct way to describe the Work Breakdown Structure (WBS) in test estimation?

easy

A. A method to automate test scripts

B. A hierarchical decomposition of testing tasks

C. A tool to find defects automatically

D. A way to write test cases faster

Solution

1. Step 1: Define Work Breakdown Structure (WBS)

   WBS breaks down the testing work into smaller, manageable tasks in a hierarchy.

2. Step 2: Match options with WBS definition

   A hierarchical decomposition of testing tasks correctly describes WBS; others describe unrelated activities.

3. Final Answer:

   A hierarchical decomposition of testing tasks -> Option B

4. Quick Check:

   WBS = Hierarchical task breakdown [OK]

Hint: WBS breaks work into smaller tasks [OK]

Common Mistakes:

• Confusing WBS with automation tools
• Thinking WBS finds defects
• Mixing WBS with test case writing speed

3. Consider the three-point estimation technique with optimistic = 4 days, most likely = 6 days, and pessimistic = 10 days. What is the estimated time using the PERT formula?

medium

A. (4 + 6 + 10) / 3 = 7 days

B. (4 + 6 + 10) / 3 = 6.67 days

C. (4 + 4*6 + 10) / 6 = 7 days

D. (4 + 4*6 + 10) / 6 = 6.33 days

Solution

1. Step 1: Recall the PERT formula for three-point estimation

   Estimated time = (Optimistic + 4 x Most Likely + Pessimistic) / 6

2. Step 2: Calculate using given values

   (4 + 4*6 + 10) / 6 = (4 + 24 + 10) / 6 = 38 / 6 ≈ 6.33 days

3. Final Answer:

   (4 + 4*6 + 10) / 6 = 6.33 days -> Option D

4. Quick Check:

   PERT estimate = weighted average [OK]

Hint: Use PERT: (O + 4M + P) / 6 for estimate [OK]

Common Mistakes:

• Using simple average instead of weighted
• Mixing up formula order
• Incorrect multiplication factor

4. A tester used expert judgment to estimate testing time but forgot to consider test environment setup. What is the likely impact on the estimate?

medium

A. The estimate will be too low, missing setup time

B. The estimate will be too high, adding extra time

C. The estimate will be accurate regardless

D. The estimate will cause syntax errors

Solution

1. Step 1: Understand expert judgment and missing factors

   Expert judgment relies on experience; missing setup means some work is ignored.

2. Step 2: Assess impact of missing setup time

   Ignoring setup causes underestimation, so estimate is too low.

3. Final Answer:

   The estimate will be too low, missing setup time -> Option A

4. Quick Check:

   Missing tasks = underestimate [OK]

Hint: Missing tasks cause underestimation [OK]

Common Mistakes:

• Assuming estimate stays accurate without all info
• Thinking missing tasks add time automatically
• Confusing estimate errors with code errors

5. You have a testing project with tasks estimated as: Task A = 3 days, Task B = 5 days, Task C = 2 days. Using WBS, you break Task B into B1 = 2 days and B2 = 4 days. What is the correct total estimate for the project?

hard

A. 3 + 5 + 2 = 10 days

B. 3 + 5 + 2 + 4 + 2 = 16 days

C. 3 + (2 + 4) + 2 = 11 days

D. 3 + 2 + 4 = 9 days

Solution

1. Step 1: Understand WBS breakdown of Task B

   Task B is split into B1 and B2, so B's estimate is sum of B1 and B2: 2 + 4 = 6 days.

2. Step 2: Calculate total estimate

   Total = Task A + Task B (broken down) + Task C = 3 + 6 + 2 = 11 days.

3. Final Answer:

   3 + (2 + 4) + 2 = 11 days -> Option C

4. Quick Check:

   WBS sums subtasks for total [OK]

Hint: Sum subtasks in WBS for total estimate [OK]

Common Mistakes:

• Adding original Task B and subtasks together
• Ignoring subtasks and using old estimate
• Miscounting total days