test two pt II
26. What are gen/spec diagrams used for?
Gen/spec diagrams are used to show general classes and the specialized classes that inherits the attributes and methods from the general class.
(2) Interface/Boundary
Human interfaces (web form, dialog box, display window, touch-tone phone), system interfaces (sending or receiving data from others)
12. List the four major steps in building decision trees.
Identify the conditions. Identify the condition alternatives. Identify the actions. Identify action rules (in order).
3. Explain the concept of inheritance in object-oriented systems.
Inheritance is when a child or derived class is created from a parent or base class. The child class inherits all the attributes and behaviors of the parent class.
6. Describe what "exploding" data flow diagrams means.
It is a process to analyze the system further to identify more detailed aspects of inputs, processes, and outputs of the system.
12. Why shouldn't compiling the data dictionary be viewed as an end in itself? -
It shouldnt be viewed as an end in itself because it is an activity that parallels systems analysis and design. The data dictionary is tied into a number of systems and helps with upgrades, etc.
16. How does a document type definition help to ensure that an XML document contains all necessary elements?
It validates the XML document using standard XML tools. The DTD(Document Type Definition) is easier to create if a data dictionary has been completed.
(3) Abstract
Linked to concrete classes in a generalization/specialization relationship.
19. What does an IDREF attribute validate?
Links one element with another that is an ID
8. What is the difference between logical and physical data structures?
Logical design shows what data the business needs for its day-to-day operations. As we learned from HCI, it is important that the logical design accurately reflect the mental model of how the user views the system. It is important that the logical design accurately reflect the mental model of how the user views the system. Using the logical design as a basis, the analyst then designs the physical data structures which include additional elements necessary for implementing the system.
22. Define method overloading.
Method overloading means using the same method or operation several times within a class. The parameters that are sent indicate which of the overloaded methods to use
5. Describe what Object Think adds to the CRC card.
Object think adds information written in plain English about the properties of an object and helps to clarify thinking about the object.
10. What is one of the major advantages of decision tables over other methods of decision analysis?
One of the major advantages of using decision tables over other methods is that decision tables help analysts ensure completeness. It is also easy to check for possible errors, such as impossible situations, contradictions, and redundancy.
16. What is partitioning, and how is it used?
Partitioning is the process of dividing a data flow diagram into manual procedures and computer programs. It is used after the physical data flow diagram has been created by examining the processes and the data flowing from one process to another.
27. What is another term for polymorphism?
Polymorphism, or method overriding, is when the specialized classes have a version of the same method contained in the general class. The subclass may add to or modify the method.
6. What is the advantage of using structured English to communicate with people in the organization?
(1) Clarifying the logic and relationships found in human language. (2) An effective communication tool, it can be taught to and understood by users in the organization.
8. List what the concept of structural things includes.
(1) Classes, which have properties or attributes and methods or operations.
11. List the diagrams included in structural diagrams.
(1)Class diagrams, used to model the static structural design of a system.
3. What are the four data items that can be symbolized on a data flow diagram?
(1)Double square for an external entity. (2)An arrow for movement of data from one point to another. (3)A rectangle with rounded corners for processes. (4)An openended rectangle for a data store.
12. List the diagrams included in behavioral diagrams. -(1)Use case diagrams, showing the actors and the use cases.
(2)Sequence diagrams- Show the sequence of activities and class relationships (3)Collaboration diagrams illustrate a sequence of object interactions showing the organization of the objects during the interactions.
(2)Object diagrams, which portray the state of class instances and their relationships at a point in time. (3)Component diagrams, which show an overview of the system architecture.
(4)A deployment diagram, which illustrates the physical implementation of the system, including the hardware.
5. Define the top-down approach as it relates to drawing data flow diagrams.
-An approach is to prepare DFDs for an overview of the system first, then add detailed aspects of the diagram. In other words, the diagrams move from general to specific.
(1) Express all login in terms of sequential structures, decision structures, case structures, or iterations.
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(2) Use and capitalize accepted keywords such as IF, THEN, ELSE, DO, and PERFORM.
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(2)Interfaces, the behavior of a class or component of a system that is noticeable from outside the class or component.
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(3) Indent blocks of statements to show their hierarchy (nesting) clearly.
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(3)Collaborations, which describe the interactions of two or more things in a system that perform a behavior that is more than any one of the things can do alone.
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(4) Underline words or phrases that have been defined in a data dictionary.
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(4)State chart diagrams show the states of an object and the events and conditions that trigger a transition from one state to another.
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(4)Use cases, which describe a series of actions that demonstrate a distinct behavior of the system and its interactions with the actors.
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(5) Clarify the logical statements.
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(5)Activity diagrams show the flow of activities within a process.
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(5)Control or active classes. A control class can initiate and control an independent flow of activity within the system. (6)Components, which are a physical part of a system that represents the services and interfaces implemented by the elements contained within that component, including software code.
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(7)Nodes, which represent a piece of hardware on which your system executes.
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13. What three advantages do decision trees have over decision tables?
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23. List the four categories into which classes fall. -
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5. List five conventions that should be followed when using structured English.
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Associations are those that are used to break up a many-to-many association between classes.
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Chapter 10
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Chapter 7
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Chapter 8
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Chapter 9
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Data structures are usually described using algebraic notation. This method allows an analyst to produce a view of the elements that make up the data structure, along with information about those elements. For instance, the analyst will denote whether there are many of the same elements in the data structure (a repeating group) or whether two elements may exist mutually exclusive of each other.
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Each data element should be defined once in the data dictionary and may also be entered previously on an element description form
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Exam 2 Study Guide
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Finally, decision trees are more readily understood by others in the organization.
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First, the order of checking conditions and executing actions is immediately noticeable.
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Second, conditions and actions of decision trees are found on some branches but not on others.
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Whole/Part are when one class represents the whole object, and other classes represent parts.
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9. Describe the difference between base and derived elements.-
A base element is one that has been initially keyed into the system. A derived element is one that is created by a process, usually as the result of a calculation or a series of decision-making statements.
4. What is a context-level data flow diagram? Contrast it to a level 0 DFD.
A context diagram is a diagram to conceptualize data flows within an organization. It usually is a list of external entities, data flows, processes, and data stores, which determines the boundary of the target system. On the other hand, a level-zero DFD is prepared to show an overview of the system including basic inputs, processes, and output. It is the highest level in a data flow diagram.
15. What is a document type definition?
A document type definition is used to determine whether the XML document content is valid (whether it conforms to the order and type of data that must be present in the document)< !DOCTYPE XML>
9. What is the difference between a logical and physical data flow diagram?
A logically-oriented data flow diagram shows how the business operates. A physically-oriented data flow diagram shows how the system will be implemented using technology and manual procedures.
29. What is a package in UML approach?
A package is a container for other UML things, such as use cases or classes. They show partitioning, or which classes are grouped into a subsystem
19. What can be depicted on a sequence or communication diagram?
A sequence or collaboration diagram shows a series of interactions between classes or object instances over time.
28. What is depicted by a statechart diagram?
A statechart diagram depicts the states that an object may have and the events that cause the object to transition to a different state. Ex. Potential student progressing to a graduated student.
2. Define what is meant by a structured decision.
A structured decision is a decision for which a representative model can be built or automated easily. It usually involves specific and single objectives which are not difficult to achieve
15. How can a use case be used to create a data flow diagram?
A use case is used to create a data flow diagram by providing a framework for obtaining processes, input, output and data stores required for user activities.
14. Would you describe a use case model as a logical or physical model of the system? Defend your answer in a paragraph.
A use case model is a logical model because it describes what the system does, rather than how the system works.
13. What is it that a use case model describes?
A use case model reflects the view of the system from the perspective of the user outside the system. It describes what the system does, rather than how the system works. DESCRIBES HOW THE SYSTEM IS USED
17. How can an analyst determine when a user interface is required?
A user interface is required for data flow that connects a manual and an automated process or an automated process with an external entity that is a person.
17. What does an activity diagram depict?
An activity diagram depicts a sequence of activities, including sequential and parallel activities, and decisions that are made
15. Define what an actor is in a use case diagram.
An actor is a role of a user that is external to the system. An actor may be a person, another system, or a device such as a keyboard
13. How can an event table be used to create a data flow diagram?
An event table is used to create a data flow diagram by analyzing each event and the data used and produced by the event. Every row in an event table represents a unique activity and is used to create one process on the data flow diagram.
10. List three reasons for creating a logical data flow diagram.
Better communication with users. More stable systems. Increased understanding of the business by analysts. A more flexible system. Elimination of redundancy
4. What does CRC stand for?
CRC stands for class, responsibilities, and collaborators.
21. What can be shown on a class diagram?
Class diagrams show classes, attributes, methods (or operations), and the relationships between classes.
19. List three ways to use completed data flow diagrams.
Completed DFDs can be used to ascertain both system's and user's information requirements, to interact with users further, and to document the system.
1. What is one of the main methods available for the analyst to use when analyzing data-oriented systems?
Data flow diagrams (DFDs).
6. What are the basic differences among data dictionary entries prepared for data stores, data structures, and data elements?
Data stores are created for each different data entity being stored. That is, when data flow base elements are grouped together to form a structural record, a data store is created for each unique structural record.
15. In which two situations do decision tables work best?
Decision tables are useful when complex combinations of conditions, actions, and rules are found or you require a method that effectively avoids impossible situations, redundancies, and contradictions
20. Why is defining classes such an important object-oriented analysis task? -
Defining classes is an important object-oriented analysis task because programming occurs at the class level
18. List three ways of determining partitioning in a data flow diagram.
Different user groups are in different programs. Processes that execute at different times are in separate programs. Processes that contain similar tasks may be included in the same program. Several batch processes may be included in the same program for efficiency. Several processes may be included in the same program or job stream for consistency of data. Processes may be separated into different programs for security.
11. List five characteristics found on a physical data flow diagram that are not on a logical data flow diagram. -
Distinguishing which processes are manual and which are automated. Sequencing processes in the order they must be executed. Temporary data stores and transaction files. Specifying actual document and file names. Controls to ensure accuracy and completeness.
10. How do the data dictionary entries relate to levels in a set of data flow diagrams?
Each level of a data flow diagram should use data appropriate to that level. As child diagrams are created, the data flow into and out of the processes becomes more and more detailed, including structural records and elements.
2. What are the four advantages of using a data flow approach over narrative explanations of data movement?
Freedom from committing to the technical implementation of the system too early. Further understanding of the interrelationships of systems and subsystems. Communicating current system knowledge to users through data flow diagrams. Analysis of the proposed system to determine if all the necessary data and processes have been defined.
(1) Entity
Represent real world items.
4. What is a structural record?
Structural record is a record that is created when data flow base elements are grouped simultaneously
7. Why are structural records used?
Structural records allow the analyst to define things like "Address" as street,(apartment) city, zip, (zip extension), and use them in many different applications.
14. In which two situations should you use structured English?
Structured English is useful when there are many repetitious actions or when communication to end users is important.
18. Write a paragraph that describes the use of swimlanes on activity diagrams.
Swimlanes are useful to show how the data must be transmitted or converted. They help divide up tasks in a team. And make the activity diagram one that people want to use to communicate with others.
11. What are the main uses of decision trees in systems analysis?
Systems analysts can use decision trees when complex branching occurs in a structured decision process. Decision trees are also useful when it is essential to keep a string of decisions in a particular sequence.
9. List what the concept of behavioral things includes.
The concept of behavioral things includes interactions, the messages sent between a set of objects, and state machine, a series of states that an object goes through in response to actions within the system.
3. What information is contained in the data repository?
The data repository contains information about the data maintained by the system including data flow diagrams, data stores, etc. It also contains procedural logic and use cases; screen and report design; data relationships; project requirements and project management information, such as delivery schedules, etc.
16. In which two situations are decision trees preferable?
The decision trees are preferable when the sequence of conditions and actions is critical or not every condition is relevant to every action.
2. Describe the difference between a class and an object. -
The difference between an Object and a Class is that the class defines shared attributes and behaviors of objects. An object is an instance or occurrence of a class.
5. List the eight specific categories that each entry in the data dictionary should contain. Briefly give the definition of each category. -
The eight specific categories that each entry in the data dictionary should contain
8. What is the first step to take in developing a decision table? -
The first step in developing decision tables is the determination of the number of conditions that may affect the decision. The number of conditions becomes the number of rows in the top half of the decision table.
9. List the four main problems that can occur in developing decision tables.
The four main problems that can occur in developing decision tables are incompleteness, impossible situations, contradictions, and redundancy.
2. What are four reasons for compiling a complete data dictionary? -
The four reasons for compiling complete data dictionaries are to: validate the dataflow diagram for completeness and accuracy; provide a starting point for developing screens and reports; determine the contents of data stored in files; and develop the logic for data flow diagram process
11. List the four steps to take in compiling a data dictionary. -
The four steps to take in compiling a data dictionary are: defining the data flows; describing data structures; looking at logical and physical data stores and looking and analyzing data elements.
13. What are the main benefits of using a data dictionary?
The main benefits of using a data dictionary is the database is simplified and information is easier to understand especially its tables and indexes.
16. What three things must a use case always describe?
The three things that a use case must describe are the actor that initiates the event, the event that triggers the use case, and the use case that performs the actions triggered by the event.
4. What are the two building blocks of structured English?
The two building blocks of structured English are (1) structured logic or instructions organized into nested and grouped procedures, and (2) simple English statements such as add, multiply, move, and so on.
25. What are the two categories of relationships between classes?
The two categories of relationships between classes are associations and whole/part relationships.
10. What are the two main types of diagrams in UML?
The two main types of diagrams in UML are structural diagrams and behavioral diagrams.
7. Which quadrant of the decision table is used for conditions? Which is used for condition alternatives?
The upper left quadrant contains the conditions, the upper right quadrant contains the condition alternatives.
3. What four elements must be known for the systems analyst to design systems for structured decisions?
They are conditions, condition alternatives, actions, and action rules.
7. What are the three major elements of UML?
Things, the objects. Relationships, the glue that holds things together. Diagrams, categorized as either structure or behavioral.
1. List three reasons for producing process specifications.
Three reasons for producing process specifications are: A. Reduce the ambiguity or vagueness of the process. B. Obtain a precise description of what is accomplished. C. Validate the system design, including data flow diagrams and the data dictionary.
7. What are the trade-offs involved in deciding how far data streams should be exploded?
Time may be wasted and understandability sacrificed if data flow diagrams are overly complex. On the other hand, if the data flow diagrams are unexploded, errors of omission could occur.
18. What does an ID attribute ensure?
To check to make sure an ID starts with a letter or an underscore and cannot solely be a number
8. Why is labeling data flow diagrams so important? What can effective labels on data flow diagrams accomplish for those unfamiliar with the system? -
To make the diagrams truly communicative, meaningful labels of all data components are required. Effective labels can help someone unfamiliar with the system understand objectives, functions, and features of the system better.
12. When are transaction files required in the system design? -
Transaction files are used to link any processes that do not execute at the same time but share the same data.
1. List two reasons for taking an object-oriented approach to systems development.
Two reasons for taking an object-oriented approach to systems development are to build systems that are responsive to a changing business landscape, and when systems are undergoing continuous maintenance, adaptation, and redesign
6. What is UML?
UML (Unified Modeling Language) is the result of a collaboration of individual object-oriented methods that has been adopted as a standard for modeling object-oriented systems.
14. List the major sections of a use case.
Use case name, Description, Trigger, Trigger type. Input name, and source Output name and destination Steps performed Information required for each step
(4) Control
Used to control the flow of activities.
30. Why is using UML for modeling important?
Using UML for modeling is important because it helps to achieve a greater understanding between the business team and the IT team regarding the requirements and processes of a system. It provides a detailed set of specifications for the classes, scenarios, activities and sequencing in the system. It helps to implement changes earlier in the project, when it is easier and less costly to
17. When should attributes be used in an XML document?
When the keyword #REQUIRED is present. #IMPLIED means that an attribute is optional
14. What does extensible markup language (XML) describe?
XML is a language that can be used to exchange data between businesses or between systems within a business (similar to HTML). XML addresses the problem of sharing data when users have different computer systems and software or different database management systems.
Element ID-
an optional entry allows the analyst to build automated data dictionary entries.
1. Define the term data dictionary. Define metadata
dictionary Data is a reference work of data about data. Metadata is a set of data that describes and gives information about other data
The length of the data-
how long the data is for example information may be standard like telephone numbers must have 10 digit
Output formats-
information on special coding or encryptions
A short description of the element-
this describes what the element is like and what it type does.
The name of the element-
this is a descriptive or unique way to name the element in the data dictionary
The type of data-
this is to show if the information is numeric, alphabetic, etc Inputs and
A comment or remark-
this is used to indicate the format of the information and explain in brief detail what is going on.
Validation criteria-
which ensures how accurate the data in the dictionary is
