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Something seems wrong in Pre-Assessment/Sample Test for Test 486

 
Greenhorn
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Please see the following question:
1)
Which of the following are TRUE about services resulting from use
cases?
a) New requirements in use cases generally result in one or more
public methods in a domain model class.
b) Private methods are required by the system's use cases.
c) Use cases drive the design of interaction diagrams, which in
turn define public methods in domain model classes.
d) Each alternative scenario of a use case generally results in a
new association between classes.
Multiple Select - Please select all of the correct answers (this
question has 2 correct choices).
a, c

As my understanding, we can not define
public methods in a domain model class. All options are wrong!

(2)
What, if anything, is WRONG with the following analysis use case?
Use case: Sell goods
Description: Accept tender from a customer, package products being purchased, and remove the products from inventory.
Actors: Clerk
Preconditions: Customer has chosen products to buy from inventory.
Postconditions: Products are no longer in inventory. Store cash balance is increased.
Steps:

A.There are design details intermixed with the requirements.
B.The actor's actions and system responses are not separated.
C."Sell goods" is too broad to be a use case.
D.There is nothing wrong with this use case.
Where is the step?
I got the step from Answers to IBM 486 sample test provided by Don Liu.
1. The clerk scans the product codes on each item being purchased.
2. As each item is scanned, the system calculates a running total,
prints line items on a receipt, and displays the line items to the clerk on
the ReceiptPanel.
3. The clerk can remove items from the purchase by pressing the "Void
item" button.
4. ?
5. Once the customer has paid for the items, the items are removed from
inventory and the cash register balance is incremented by the total
amount of the good sold.
Why does the step not exist in MY SAMPLE TEST !
(3)
Which of the following are recommended when developing an OO system?

A.Write a description of the concept that a class represents whenever a new class is declared.
B.Use interfaces for types or roles that objects may play, independent of their location in the class hierarchy.
C.Apply design patterns where applicable in the system.
D.Name classes based on their design specifics, such as "array" or "queue".
Select the best answer.
It seems obviously that a), b) c) are right answers. but according to the question, I only can select one question. which one is the best one? Why there are 3 options in the Answers to IBM 486 sample test provided by Don Liu
Please help me!
 
author
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I would agree with you on 1), don't know about 2).
In 3), there seems to be a "not" missing in the question?
 
xjl xu
Greenhorn
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Thank you for your replay!
According to your replay, at least two question of them are wrong! the other one is not sure.
The problem is why my sample test question is different with the question provided by Liu Dong?
I think these kind of wrong question will mislead the tester.
thanks,
 
Ranch Hand
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Originally posted by xjl xu:
[QB]The problem is why my sample test question is different with the question provided by Liu Dong?
[QB]


It is possible. I took the exam last April. Hopefully, UML and OOAD didn't change much. So you can still practise even it is old. And I am sure someone will take care of the new exam as well.
 
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Hi,
Does domain model class & conceptual classes are same thing? If yes, then there is no correct answer of question#01, because we cannot define methods in conceptual classes.
Bye,
Viki.
 
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Viki,
why?
or
(exam oriented) where does Larman say that?
In my understanding classes shall define operations (methods) in Analysis stage.
J. Arlow, I. Neustadts: UML and the Unified Process (good one) seems to back this.
Am I missing something important?
 
Ilja Preuss
author
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Originally posted by Axel Janssen:
Viki,
why?
or
(exam oriented) where does Larman say that?
In my understanding classes shall define operations (methods) in Analysis stage.


Because operations are not methods - they don't even necessarily map to methods. At least the way I understand OOA...
 
Vikrama Sanjeeva
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Hi,
In UML operations may be behaviour or may be attributes or even may be clump of both behaviour and attribute. I understands operation like this. A single funtional responibilty of a system is considered as operation. There may be various methods are called in order to full fill this operation. Developing conceptual diagram is part of OOA, in which we don't define operations (i.e methods). That is a class diagram without behaviour section. Reason to why we don't define methods? In my opinion, in OOA we concentrate on finding concepts and attributes of the concepts.
My question remain un-answered. That is does domain model class and conceptual model class are same thing?
Bye,
Viki.
 
John Lee
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Originally posted by Vikrama Sanjeeva:
Hi,
Does domain model class & conceptual classes are same thing? If yes, then there is no correct answer of question#01, because we cannot define methods in conceptual classes.
Bye,
Viki.


Hi:
Domain model class & conceptual classes are not the same thing. There is no class in domain model. conceptual class is fictional class, such as register, they are not like flight, airport, which are riginated from reality. Defining methods is not the main task until class diagram phrase.
HTH.
 
Axel Janssen
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o.k. my use of "methods" was an example of serious confusion of terms.
The things in the 3rd compartment of an UML are called operations, if we are in analysis step.
Fowler puts it clear:


An operation is something that is invoked on an object (the procedure call), whereas a method is the body of procedure. The two are different when you have porymorphis. If you have a supertype with 3 subtypes, each of which overrides the supertype's "foo" operation, you have 1 operation and 4 methods that implement it.
Fowler, Uml Distilled, p. 59


One could argue that yes I meant method declaration, not method body, but methods should be connected to software (something which could be compiled). In analysis context: operations.
Back to questions of ICE test.
I think the guys at Torolab might have confused the terms "Domain Model Class" and "Design Class Diagramm", if we take Larmans, Applying UML and Patterns as the authorative source.
Larman calls Domain model


the decomposition of a domain of interest into individual conceptual classes or objects [...] Using UML notation, a domain model is illustrated with a set of class diagrams in which no operations are defined.
P.


He calls those abstraction one might find in this step of analysis conceptual classes.
A Sale class (or better a Sale conceptual class, hehe) in a Domain Model does not represent a software definition, it is an abstraction of a real world concept.
Design Model Classes by contrast express the definition of classes as software components (Larman, 287). These have methods(!!!) and are using interaction diagrams as their input (see answer c). They belong to design phase.

Domain Model classes/Conceptual classes without operations seems to be a Larman speciality. :roll:
Fowler uses the different perspectives Conceptual, Specification, Implementation for the use of UML-class diagrams in different phases of the iterations.
"A conceptual class should be drawn with little or no regard for the software that implements it. It represents the concepts in the domain under study." If you compare this with Larmans Domain Model/Conceptual Class definition, its very close. Fowler proposes to use operations in conceptual models.


"[...]Within conceptual models, you shouldn't use operations to specify the interface of a class. Instead, use them to indicate the principal responsibilities of that class, perhaps using a couple of words summarizing a CRC responsibility. (Larman, UML distilled, p. 59.



Arlow, Neustadt come up with the term analysis classes for something very close or equal.


Analysis classes are classes that
- represent a crisp abstration in the problem domain.
- should map on to real-world business concepts (and be carefully named accordingly)
Arlow, Neustadt, UML and the Unified Process, p. 129


And you guessed it. They are with operations.
2:1
So: This should be correct (in my view):
a) New requirements in use cases generally result in one or more methods in a Design Class Diagramm or Fowler Style Conceptual Classes
c) Use cases drive the design of interaction diagrams, which in turn define public methods in Design Class Diagramm (Fowler Style Conceptual Classes wouldn't fit here, cause its specification or implementation perspective).
Someone might think a little more about it and ask the Torolab guys per email. I would do that if there is no message here until weekend.

Axel
[ March 04, 2003: Message edited by: Axel Janssen ]
[ March 04, 2003: Message edited by: Axel Janssen ]
 
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