ISTQB - International Software Testing Qualifications Board Black-Box Test Design Questions and Answers — Questions and Answers
Question 1: An online retail system offers a 10% discount for preferred customers on orders totaling between $100.00 and $500.00, inclusive. For non-preferred customers, the discount does not apply. Which black-box test design technique is MOST appropriate for verifying the complex logic of applying this discount based on customer status and order total?
- State Transition Testing
- Decision Table Testing (Correct answer)
- Use Case Testing
- Boundary Value Analysis
Correct answer: Decision Table Testing
Decision Table Testing is the most suitable technique because it is specifically designed to handle complex business rules with multiple conditions (customer status, order total) and their resulting actions (discount applied, no discount). It systematically covers all combinations of these conditions.
Question 2: A tester is designing tests for a password entry field which must be between 8 and 16 characters long. Using two-value Boundary Value Analysis (BVA), which set of test cases represents the most effective values to check?
- 7, 8, 16, 17 (Correct answer)
- 8, 12, 16
- 7, 9, 15, 17
- 6, 7, 8, 16, 17, 18
Correct answer: 7, 8, 16, 17
Two-value Boundary Value Analysis tests the values on the boundary and the first value outside the boundary. For the valid range of 8-16, the lower boundary is 8 (with its outside value being 7) and the upper boundary is 16 (with its outside value being 17). Therefore, the correct set of values is 7, 8, 16, and 17.
Question 3: A loan application system transitions through several statuses: 'New', 'In Review', 'Approved', 'Rejected', and 'Closed'. An application can only be moved to 'In Review' from 'New'. From 'In Review', it can be moved to either 'Approved' or 'Rejected'. An 'Approved' application can then be 'Closed'. Which of the following represents an invalid transition in this system?
- In Review -> Approved
- New -> Closed (Correct answer)
- New -> In Review
- Approved -> Closed
Correct answer: New -> Closed
Based on the rules provided, there is no direct path from the 'New' state to the 'Closed' state. This represents an invalid transition. State Transition Testing is used to model this type of behavior and identify both valid and invalid sequences of events.
Question 4: A web form has an age input field that accepts values from 18 to 99. Using the Equivalence Partitioning technique, which set of test cases would provide the best coverage with the minimum number of tests?
- 17, 18, 99, 100
- 18, 50, 99
- 17, 50, 100 (Correct answer)
- 1, 25, 101
Correct answer: 17, 50, 100
Equivalence Partitioning divides inputs into groups that are expected to be processed similarly. For the range 18-99, there are three partitions: one invalid partition below the range (<18), one valid partition (18-99), and one invalid partition above the range (>99). The most efficient approach is to select one representative value from each partition, such as 17 (invalid), 50 (valid), and 100 (invalid).
Question 5: What is the primary objective of Use Case Testing?
- To ensure that all combinations of input conditions and resulting actions are covered.
- To verify the system's behavior at the boundaries of its input ranges.
- To validate that the system correctly handles transitions between different operational states.
- To test end-to-end business process flows from a user's perspective. (Correct answer)
Correct answer: To test end-to-end business process flows from a user's perspective.
Use Case Testing focuses on executing tests based on 'use cases', which describe interactions between a user (or 'actor') and the system to achieve a specific goal. This makes it ideal for verifying complete business process flows and finding defects in real-world user scenarios.
Question 6: A tester is analyzing requirements for a feature that describes the lifecycle of a document in a content management system (e.g., Draft, In Review, Published, Archived). The system's behavior changes depending on the document's current status and the user's action. Which black-box technique is MOST suitable for designing tests for this feature?
- Boundary Value Analysis
- Equivalence Partitioning
- State Transition Testing (Correct answer)
- Decision Table Testing
Correct answer: State Transition Testing
State Transition Testing is specifically designed for systems where the behavior depends on its current state and past events. It models the different statuses (states) of an object and the events (transitions) that cause it to change state, which is a perfect match for testing a document lifecycle.
ISTQB - International Software Testing Qualifications Board Black-Box Test Design Questions and Answers
An online retail system offers a 10% discount for preferred customers on orders totaling between $100.00 and $500.00, inclusive.
For non-preferred customers, the discount does not apply.
Which black-box test design technique is MOST appropriate for verifying the complex logic of applying this discount based on customer status and order total?