CH DFD (test bank) Flashcards
T/F: The traditional approach to system development views a system as a collection of interacting objects
F
T/F: Traditional computer processes are much like procedural computer programs in that they contain instructions that execute in sequence.
T
T/F: The object-oriented approach to systems development views a system as a collection of processes, some performed by people and some performed by the computer.
F
T/F: The term “diagram 0” is used synonymously with context diagram.
F
T/F: System boundaries are not shown clearly on context diagrams.
F
T/F: Diagram 0 summarizes an entire system or subsystem in greater detail than a context diagram.
T
T/F: Context diagrams do not usually show data stores.
T
The traditional approach to information systems development describes activities as ____.
a. processes carried out by people or computers
b. objects that interact with people and each other
c. objects that send and respond to messages
d. activities that require computational support
a. processes carried out by people or computers
A(n) ____ is a person or organization outside the system boundary that supplies data inputs or accepts data outputs.
a. data flow c. external agent
b. data store d. customer
c. external agent
Which of the following refers to a modeling technique that breaks the system into a hierarchical set of increasingly more detailed models?
a. Data store c. Data flow
b. Level of abstraction d. Context diagram
b. Level of abstraction
A(n) ____ is a data flow diagram (DFD) that summarizes all processing activity within the system in a single process symbol.
a. Event partition diagram c. Diagram 0
b. level of abstraction d. context diagram
d. context diagram
A(n) ____ represents the system response to one event.
a. DFD fragment c. diagram 0
b. context diagram d. event-partitioned system model
a. DFD fragment
A data flow diagram (DFD) that models system requirements using a single process for each event in a system or subsystem is called a(n) ____.
a. context diagram c. event-partitioned system model
b. DFD fragment d. diagram 1.0
c. event-partitioned system model
The term diagram 0 is another name for a(n) ____.
a. context diagram c. event-partitioned system model
b. DFD fragment d. lowest level diagram
c. event-partitioned system model
If the data flow diagram (DFD) is a ____, then it assumes that the system will be implemented with perfect technology.
a. context diagram c. physical model
b. logical model d. prototype model
c. physical model
A(n) ____ can be a physical system model, a logical system model, or a blend of the two.
a. process definition c. entity-relationship diagram
b. data flow diagram d. context diagram
b. data flow diagram
Which of the following data flow diagram (DFD) symbols usually corresponds to a data entity on an entity-relationship diagram (ERD)?
a. Data store c. Data link
b. Data flow d. Process
a. Data store
Which of the following data flow diagram (DFD) symbols represents the communication between an external agent and a process while the process is executing?
a. Process c. Real-time link
b. Data link d. Data store
c. Real-time link
An analyst can avoid information overload by adhering to the rule of ____.
a. functional decomposition c. process dependency
b. interface minimization d. balancing
b. interface minimization
____ is the equivalence of data content between data flows entering and leaving a process and data flows entering and leaving a process decomposition data flow diagram (DFD).
a. Balancing c. Complexity minimization
b. Interface minimization d. Abstraction
a. Balancing
Minimization of interfaces is directly related to the rule of ____.
a. miracle c. balancing
b. black hole d. 7 ± 2
d. 7 ± 2
On a DFD a(n) ____ represents a file or part of a database that stores information about a data entity.
a. process c. data store
b. data flow d. data link
c. data store
Which of the following is NOT a technique to document program logic for a process.
a. Structured English c. Decision Tree
b. Decision Matrix d. Decision Table
b. Decision Matrix
Analysts sometimes can spot black holes and miracles simply by examining the _________.
a. context diagram c. data flow diagram
b. entity relationship diagram d. structured English
c. data flow diagram
Which of the following is a table that describes the relationship between processes and the locations in which they are performed?
a. Location diagram c. Activity-location matrix
b. Black hole d. Activity-data matrix
c. Activity-location matrix
Which of the following is a diagram or map that identifies all of the processing locations of a system?
a. Location diagram c. Activity-data matrix
b. Activity-location matrix d. CRUD table
a. Location diagram
A ____ is a textual description of a data flow’s content and internal structure.
a. data store rule c. data flow rule
b. data flow definition d. process definition
b. data flow definition
In small development projects, a(n) ____ may be a small loose-leaf notebook or word processing file.
a. data store c. activity-data matrix
b. data dictionary d. decision table
b. data dictionary
A symbol on a data flow diagram (DFD) that represents an algorithm or procedure by which data inputs are transformed into data outputs is called a(n) ____.
a. process c. activity
b. transaction d. data flow
a. process
A diagram that represents system requirements as processes, external agents, data flows, and data stores is called a(n) ______.
data flow diagram (DFD)
A symbol on a data flow diagram (DFD) that represents an algorithm or procedure by which data inputs are transformed into data outputs is called a(n) __________.
process
A place where data are held pending future access by one or more processes in a DFD is called a(n) ________.
data store
A(n) ________ is a data flow diagram (DFD) that summarizes all processing activity within the system in a single process symbol.
context diagram
A DFD _______ represents the system response to one event within a single process symbol.
fragment
An assumption about DFDs that includes things such as instant processing, infinite storage, and zero errors is called ______.
perfect internal technology
A data flow diagram (DFD) that models system requirements using a single process for each event in a system or subsystem is called a(n) ____.
event-partitioned system model
diagram 0
If too much information is presented at once, people experience a phenomenon called _______ .
information overload
The rule of 7 ± 2 is also known as _________.
Miller’s number
_________ is a principle of model design that seeks simplicity by limiting the number of connections among model components.
minimization of interfaces
The term “__________” is used to describe the equivalence of data content between data flows entering and leaving a process and data flows entering and leaving a process decomposition data flow diagram (DFD).
balancing
A process or data store with data input that is never used to produce a data output is referred to as a(n) ______.
black hole
___________ is a method of writing process specifications that combines structure programming techniques with narrative English.
Structured English
A(n) _______ is a process or data store with a data element that is created out of nothing.
miracle
___________ can summarize decision logic more concisely than structured English.
decision tables
A(n) ________ is a graphical description of process logic that uses lines organized like branches of a tree.
decision tree
A(n) _______ is a tabular representation of processing logic containing decision variables, decision variable values, and actions or formulas.
decision table
A(n) ________ is a table that describes stored data entities, the locations from which they are accessed, and the nature of the accesses.
activity-data matrix
Explain the difference between traditional and object-oriented approaches to system development.
The traditional and the object-oriented approaches to system development differ in how a system’s response to an event is modeled and implemented. The traditional approach views a system as a collection of processes, some performed by people and some performed by computers. In contrast, the object-oriented approach views a system as a collection of interacting objects. Objects are capable of behaviors that allow them to interact with each other and with people using the system.
List the five symbols used on a data flow diagram (DFD) and briefly explain what each symbol represents.
A process (rectangle with rounded corners) represents transformation of data input(s) into data output(s).
A data flow (straight arrow) represents movement of data among processes, data stores, and external agents.
An external agent (square) represents a person, organization, or system outside the system boundary that supplies or receives data.
A data store (rectangle with one end open) represents data stored for later retrieval.
A real-time link (arrow with a double bend) represents exchange of data between a process and an external agent while the process is executing.
What are the first four steps involved in the construction of a decision table?
- Identify each decision variable and its allowable values.
- Compute the number of decision variable combinations as the product of the number of values of each decision table.
- Construct a table with one more column than the number of decision variable combinations computed in step 2.
- Assign the decision variable with the fewest values to the first row of the table. Put the decision variable name in the first column. Divide the remaining columns into sets of columns for each decision variable value.
