Computer Science 223 Discussion Questions

Alhir, Pages 71-84

Discussion questions submitted for pages 71-84 of Alhir:

Miscellaneous Questions

  1. Is there any significance to the shapes and patterns used in UML that would make them easier to remember? -Jim Finnessy
  2. Is it possible that the same objects could have multiple lines connnecting them? Or would this indicate that you have a problem? -Peter Likarish
  3. In the project-activity relationship, when will there be multiplicty string attatched to the project class? Steve F
  4. UML seems to support many levels of abstraction. How much UML detail should be used in planning before switching to pseudocode and/or just coding it? How much do people usually actually use?
  5. What is the importance of an "anonymous object" in UML, or for that matter and object-oriented design? George
  6. Why are all the UML diagrams object-oriented (ie. guided by inheritance) if UML is not exclusively an object-eriented modeling language?
  7. In what different ways would one go about diagramming a program that is meant to be extraordinarily modularized, versus one that is meant to be more of an integrated program? -Jonathan Kensler
  8. Are all objects anonymous? (Raz Magar)
  9. The object djiagrams described in the text strike me as very confusing. I am can understand their use as test cases, but wouldn't an exhaustive set of object-diagrams be necessary to test a system. It seems to be that test cases could be better generated by focusing on the functionality of each aspect of the system, rather than attempting to test the entire system at once. Am I simlpy thinking as an imperative programmer used to debugging imperative code, or would that be a valid way to use object diagrams? josh vickery
  10. What are the parts of UML that are non-intuitive? What do I need to know that I cannot figure out by examining the diagram?
  11. Is there a particular order in which the Resource Manager, the Project Manager and the System Administrator should proceed when executing their tasks?
  12. Since the book does not provide one, what is an example of a case in which protected visibility is most appropriate? --Khong
  13. What are the exact functions that the resource administrator, the system administrator, and the project manager perform? Patrick Dowd
  14. In use-case diagrams, how closely should we associate the individual elements (which seem to correspond to methods) with what will end up being classes? Will they correspond to classes or objects in the final design? (-Nick)
  15. Could you give an example of a destroyer operation in java? -Todd
  16. What is the purpose of a qualifier?(Sam Vanderhyden)
  17. It seems that the author throws different kinds of examples with UML in the book. Is the UML used only in a technical side of software engineering, or is it used even to diagram the real life relationships among people and other things? --Hisako
  18. What is an example of a composition and a aggregation relationship? Taha
  19. Is it beneficial to have UML diagrams at different levels of the hierarchy so that the complexity of the program could be better understood? -Jim Finnessy
  20. Since abstract classes cannot have instances, can they directly be related to another class, other than one that extends/inherits them? -Peter Likarish
  21. Are the diagrams just examples or does the UML actually used in the accounting process of software development? Steve F
  22. UML looks useful for generating interfaces. Is is commonly used so? If so, do we have software that does this? If not, what does it lack?
  23. Could you give an example of composition and aggregation in action the Class diagram? George
  24. In the use case model, can an activity be extended by a use case and also be used by another use case? Anthony
  25. What are some common mistakes made in UML diagramming? -Jonathan Kensler
  26. Would it be meaningful to have two-way associations between classes? If so, under what scenarios? (Raz Magar)
  27. Looking at class diagrams I can see how a case tool could easily translate them to stub classes in some object oriented programming languages. Do case tools that have this functionality differ at all in their UML tools based on the destination language that they use? josh vickery
  28. Must actors always be square objects or stick figures?
  29. How do we create a Skills and Resources Class Diagram moving from Resource Class Diagram?
  30. The author uses small models as examples of the different types of diagrams, but is there a prescriptive method for creating diagrams or models? --Khong
  31. Can you clarify the differences between project, activities, and tasks in UML? Patrick Dowd
  32. What are some of the programs available for creating UML diagrams? Do they create project files in all of the primary object-oriented languages? (-Nick)
  33. Could you expand on the definition of "protected?" -Todd
  34. What are the advantages of using an anymous object?(Sam Vanderhyden)
  35. There are different kind of diagrams. How are these used together? Are different kinds of diagram combined in one big diagram, or are they kept seperately? --Hisako
  36. How are object diagrams and class diagrams linked and is there a way in which they are connected so a user can get an overall picture of the workings of the program? Taha
  37. I don't understdand what a generalization relationship is. Is it that two classes are being used in place of a third one? Elias Vafiadis
  38. What does an anonymous object mean exactly and is every object anonymous?
  39. Is multiplicity important? Why is it necessary to know the number objects of a class that are assigned to another object(s) of a different class? Elias Vafiadis
  40. Can you clarify the function of an association class?
  41. I didn't understand why the Back Up Data use case is a connected option to the Shut Down System use case through an extends relationship? (Desi Dimova)
  42. "Objects diagrams describe the static structure of a system at a particular time," which makes me think that it would be hard for UML diagrams to present a dynamic structure, and yet most of the structures UML diagrams refer to are dynamic. What are the pluses and minuses of representing a dynamic structure with a static diagram? (Desi Dimova)

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