ISTQB Chapter 4 Questions And Answers: Test Design Techniques

1. Which is not true-The black box tester?

Should be able to understand functional specification or requirements document

Should be able to understand the source code.

Is highly motivated to find faults

Is creative to find the system’s weaknesses

The black box tester should be able to understand the functional specification or requirements document, as this is essential for testing the system based on its intended functionality. They should also be highly motivated to find faults and creative in identifying the system's weaknesses. However, it is not necessary for the black box tester to understand the source code, as their focus is on testing the system from an external perspective, without knowledge of its internal workings.

Explanation

The black box tester should be able to understand the functional specification or requirements document, as this is essential for testing the system based on its intended functionality. They should also be highly motivated to find faults and creative in identifying the system's weaknesses. However, it is not necessary for the black box tester to understand the source code, as their focus is on testing the system from an external perspective, without knowledge of its internal workings.

2. Which of the following is a form of functional testing?

Boundary value analysis

Usability testing

Performance testing

Security testing

Boundary value analysis is a form of functional testing that involves testing the boundaries or extreme values of input variables. It focuses on testing the behavior of the system at the boundaries of the input domain, such as the minimum and maximum values, to ensure that the system handles these values correctly. This type of testing helps identify errors or issues that may occur at the edges of the input range and is commonly used to improve the quality and reliability of software systems.

Explanation

Boundary value analysis is a form of functional testing that involves testing the boundaries or extreme values of input variables. It focuses on testing the behavior of the system at the boundaries of the input domain, such as the minimum and maximum values, to ensure that the system handles these values correctly. This type of testing helps identify errors or issues that may occur at the edges of the input range and is commonly used to improve the quality and reliability of software systems.

3. Given the following state transition diagram which of the following series of
state transitions contains an INVALID transition which may indicate a fault in the system
design? Exhibit:

Login Browse Basket Checkout Basket Checkout Pay Logout.

Login Browse Basket Checkout Pay Logout.

Login Browse Basket Checkout Basket Logout.

Login Browse Basket Browse Basket Checkout Pay Logout.

The series of state transitions "Login Browse Basket Checkout Basket Logout" contains an INVALID transition which may indicate a fault in the system design. The transition from "Checkout" back to "Basket" is not a valid transition as it skips the "Pay" state. This could indicate a problem in the system design where the user is able to go back to the "Basket" state without completing the payment process.

Explanation

The series of state transitions "Login Browse Basket Checkout Basket Logout" contains an INVALID transition which may indicate a fault in the system design. The transition from "Checkout" back to "Basket" is not a valid transition as it skips the "Pay" state. This could indicate a problem in the system design where the user is able to go back to the "Basket" state without completing the payment process.

4. Which of the following is NOT a white box technique?

Statement testing

Path testing

Data flow testing

State transition testing

State transition testing is not a white box technique because it focuses on testing the behavior and functionality of a system based on different states and transitions, rather than examining the internal structure or implementation details of the system. White box techniques, on the other hand, involve testing the internal logic and code of the system.

Explanation

State transition testing is not a white box technique because it focuses on testing the behavior and functionality of a system based on different states and transitions, rather than examining the internal structure or implementation details of the system. White box techniques, on the other hand, involve testing the internal logic and code of the system.

5. A program validates a numeric field as follows: values less than 10 are rejected, values between 10 and 21 are accepted, and values greater than or equal to 22 are rejected, which of the following covers the MOST boundary values?

9,10,11,22

9,10,21,22

10,11,21,22

10,11,20,21

The correct answer is 9,10,21,22. This answer covers the most boundary values because it includes the lowest rejected value (9), the lowest accepted value (10), the highest accepted value (21), and the lowest rejected value (22).

Explanation

The correct answer is 9,10,21,22. This answer covers the most boundary values because it includes the lowest rejected value (9), the lowest accepted value (10), the highest accepted value (21), and the lowest rejected value (22).

6. A program validates a numeric field as follows: values less than 10 are rejected, values between 10 and 21 are accepted, and values greater than or equal to 22 are rejected which of the following input values cover all of the equivalence partitions?

10,11,21

3,20,21

3,10,22

10,21,22

The given input values cover all of the equivalence partitions because:
- 3 is less than 10, so it is rejected.
- 10 is between 10 and 21, so it is accepted.
- 22 is greater than or equal to 22, so it is rejected.
Therefore, the input values 3, 10, and 22 cover all of the equivalence partitions for the given validation rules.

Explanation

The given input values cover all of the equivalence partitions because:
- 3 is less than 10, so it is rejected.
- 10 is between 10 and 21, so it is accepted.
- 22 is greater than or equal to 22, so it is rejected.
Therefore, the input values 3, 10, and 22 cover all of the equivalence partitions for the given validation rules.

7. A thermometer measures temperature in whole degrees only. If the temperature falls below 18 degrees, the heating is switched off. It is switched on again when the temperature reaches 21 degrees. What are the best values in degrees to cover all equivalence partitions?

15, 19 and 25.

17, 18 and19.

18, 20 and22

16, 26 and 32

The best values to cover all equivalence partitions are 15, 19, and 25. A thermometer measures temperature in whole degrees only, so the values must be whole numbers. The heating is switched off when the temperature falls below 18 degrees and switched on again when it reaches 21 degrees. Therefore, the values below 18 (15) and between 18 and 21 (19) are important to cover. Additionally, the highest value mentioned (25) is necessary to cover temperatures above 21 degrees.

Explanation

The best values to cover all equivalence partitions are 15, 19, and 25. A thermometer measures temperature in whole degrees only, so the values must be whole numbers. The heating is switched off when the temperature falls below 18 degrees and switched on again when it reaches 21 degrees. Therefore, the values below 18 (15) and between 18 and 21 (19) are important to cover. Additionally, the highest value mentioned (25) is necessary to cover temperatures above 21 degrees.

8. A person deals in selling printer cartridges. The minimum order quantity for the cartridges is 5 units. The dealer offers a 20% discount for orders of 100 or more printer cartridges. You have been asked to prepare test cases using various values for the number of printer cartridges ordered. Which of the following groups contain three test inputs that would be generated using Boundary Value Analysis?

5, 6, 20

4, 5, 80

4, 5, 99

1, 20, 100

Boundary Value Analysis (BVA) involves selecting test cases at the boundaries of input domains. In this scenario, the boundary conditions include the minimum order quantity (5 units) and the threshold for the discount (100 units). Test cases should cover values at and around these boundaries to ensure robust testing.

The groups that contain three test inputs generated using Boundary Value Analysis are:

4, 5, 6: This covers values just below and just above the minimum order quantity (5 units).

99, 100, 101: This covers values just below and just above the threshold for the discount (100 units).

Therefore, the correct answer is not listed among the options provided. However, if we were to choose the closest option, it would be:

4, 5, 100

Explanation

Boundary Value Analysis (BVA) involves selecting test cases at the boundaries of input domains. In this scenario, the boundary conditions include the minimum order quantity (5 units) and the threshold for the discount (100 units). Test cases should cover values at and around these boundaries to ensure robust testing.

The groups that contain three test inputs generated using Boundary Value Analysis are:

4, 5, 6: This covers values just below and just above the minimum order quantity (5 units).

99, 100, 101: This covers values just below and just above the threshold for the discount (100 units).

Therefore, the correct answer is not listed among the options provided. However, if we were to choose the closest option, it would be:

4, 5, 100

9. In a system designed to work out the tax to be paid: An employee has £4000 of salary tax free. The next £1500 is taxed at 10% The next £28000 is taxed at 22% Any further amount is taxed at 40% Which of these groups of numbers would fall into the same equivalence class?

£4800; £14000; £28000

£5200; £5500; £28000

£28001; £32000; £35000

£5800; £28000; £32000

The given groups of numbers would fall into the same equivalence class because they all have the same tax rates applied to their respective salary amounts. The first £4000 of salary is tax-free for all groups. The next £1500 is taxed at 10% for all groups. The next £28000 is taxed at 22% for all groups. Any further amount is taxed at 40% for all groups. Therefore, the tax calculations for these groups would be the same, making them fall into the same equivalence class.

Explanation

The given groups of numbers would fall into the same equivalence class because they all have the same tax rates applied to their respective salary amounts. The first £4000 of salary is tax-free for all groups. The next £1500 is taxed at 10% for all groups. The next £28000 is taxed at 22% for all groups. Any further amount is taxed at 40% for all groups. Therefore, the tax calculations for these groups would be the same, making them fall into the same equivalence class.

10. Which of the following is the component test standard?

IEEE 829

IEEE 610

BS7925-1

BS7925-2

BS7925-2 is the correct answer because it is a recognized component test standard. IEEE 829 is a standard for software test documentation, IEEE 610 is a standard for software engineering, and BS7925-1 is a standard for software component testing, but BS7925-2 specifically focuses on component testing and is therefore the correct choice.

Explanation

BS7925-2 is the correct answer because it is a recognized component test standard. IEEE 829 is a standard for software test documentation, IEEE 610 is a standard for software engineering, and BS7925-1 is a standard for software component testing, but BS7925-2 specifically focuses on component testing and is therefore the correct choice.