Use Case Notation Quiz 2 - Explanation

The correct answers are indicated below, along with the text that explains the correct answers.

 
11. The purpose of the <<Extends>> stereotype is to identify
Please select the best answer.
  A. Screen flows for the application
  B. System workflows
  C. One use case as a specialization of another use case
  D. Delegation between use cases
  The correct answer is C.
The purpose of the <<Extends>> stereotype is to identify one use case as a specialization of another use case. A and B are incorrect because system workflows and screen flow can be derived using the pre-conditions on use cases, but there is no explicit notation in the use case view. Delegation is signified by the<<Uses>> stereotype, so D is also incorrect.

12. The purpose of the use case view is to
Please select the best answer.
  A. Find the objects to use in building the object model
  B. Describe how people want to implement their procedures
  C. Define the goals of the system within a specific context of users
  D. Provide a textual specification for people who do not understand the models
  The correct answer is C.
The purpose of the use case view is to define the goals of the system within a specific context of users. A is incorrect because although the use case view is one source for finding objects, this is not its primary purpose. B is incorrect because the use case view avoids any discussion of implementation or procedures. D is incorrect because although textual supplements can be very helpful, this is not the purpose of the use case view.

13. The purpose of the use case narrative is to
Please select the best answer.
  A. Provide an alternative specification for people who do not understand the diagram
  B. Form the basis for writing test cases
  C. Describe the workflow process of the use case
  D. Describe the use case goal in terms of actor-system interaction
  The correct answer is D.
The purpose of the use case narrative is to describe the use case goal in terms of actor-system interaction. A is incorrect because the use case icon alone simply is not enough to define a use case, so the use case narrative is a necessary element for anyone using the use case view, not just for people unfamiliar with the diagram. B is incorrect because scenarios, not the use case narrative, form the basis for test cases. Once again, use cases are not about processes, they are about goals, so C is incorrect.

14. The parts of a use case narrative are
Please select the best answer.
  A. Assumptions, pre-conditions, dialog, post-conditions
  B. Use case diagram and scenarios
  C. Actors, use cases, associations, and the system
  D. Stereotypes, associations, and use cases
  The correct answer is A.
The parts of a use case narrative are assumptions, pre-conditions, dialog, and post-conditions.

15. Assumptions are
Please select the best answer.
  A. Implementation constraints on the design of the use case
  B. Conditions that must test true before executing the use case but are outside the responsibility of the use case to test
  C. Conditions that must test true before executing the use case and are the responsibility of the use case to test
  D. Conditions that must test true and are the responsibility of the use case to test before proceeding
  The correct answer is B.
Assumptions are conditions that must test true before executing the use case but are outside the responsibility of the use case to test.

16. Pre-conditions are
Please select the best answer.
  A. Implementation constraints on the design of the use case
  B. Conditions that must test true before executing the use case but are outside the responsibility of the use case to test
  C. Conditions that must test true before executing the use case and are the responsibility of the use case to test
  D. Conditions that must test true and are the responsibility of the use case to test before proceeding
  The correct answer is C.
Pre-conditions are conditions that must test true before executing the use case and are the responsibility of the use case to test.

17. The use case dialog is the
Please select the best answer.
  A. Screen flow through a set of tasks
  B. Data flow between the actor and the use case
  C. Sequence of interactions between the actor and the use case
  D. Process description for a workflow
  The correct answer is C.
The use case dialog is the sequence of interactions between the actor and the use case.

18. Post-conditions are
Please select the best answer.
  A. Implementation constraints on the design of the use case
  B. Conditions that must test true after executing the use case but are outside the responsibility of the use case to test
  C. Conditions that must test true after executing the use case and are the responsibility of the use case to test
  D. Conditions that must test true and are the responsibility of the use case to test before proceeding
  The correct answer is C.
Post-conditions are conditions that must test true after executing the use case and are the responsibility of the use case to test.

19. A scenario is
Please select the best answer.
  A. A single logic path through a use case
  B. A workflow path of the system
  C. A screen navigation options
  D. A combination of use cases
  The correct answer is A.
A scenario is a single logic path through a use case.

20. The purpose of scenarios is to
Please select the best answer.
  A. Decompose the use case process
  B. Identify variations on the use case process
  C. Identify interactions between use cases
  D. Run test cases
  The correct answer is C.
The purpose of scenarios is to identify interactions between use cases. A is incorrect because functional decomposition is deliberately avoided when developing use cases. B is incorrect because variations on a use case are typically identified using a separate use case and the <<Extends>> stereotype. Scenarios help identify and define test cases but do not actually run test cases, so D is also incorrect.