IT 510 Ch 6

Question 1

Activity diagram

Answer 1

A diagram that resembles a horizontal flowchart that shows the actions and events as they occur. Activity diagrams show the order in which actions take place and identify the outcome.

Question 2

Attribute

Answer 2

A single characteristic or fact about an entity. An attribute, or field, is the smallest piece of data that has meaning within an information system. For example, a Social Security number or company name could be examples of an attribute. In object-oriented analysis, an attribute is part of a class diagram that describes the characteristics of objects in the class. Also known as a data element.

Question 3

Cardinality

Answer 3

A concept that describes how instances of one entity relate to instances of another entity. Described in entity-relationship diagrams by notation that indicates combinations that include zero or one-to-many, one-to-one, many-to-many.

Question 4

Child

Answer 4

In inheritance, a child is the object that derives one or more attributes from another object, called the parent.

Question 5

Class diagram

Answer 5

A detailed view of a single use case, showing the classes that participate in the use case and documenting the relationship among the classes.

Question 6

Encapsulation

Answer 6

The idea that all data and methods are self-contained, as in a black box.

Question 7

Focus

Answer 7

In a sequence diagram, a focus indicates when an object sends or receives a message. It is indicated by a narrow vertical rectangle that covers the lifeline.

Question 8

Inheritance

Answer 8

A type of object relationship. Inheritance enables an object to derive one or more of its attributes from another object (e.g., an INSTRUCTOR or object may inherit many traits from the EMPLOYEE object, such as hire date).

Question 9

Instance

Answer 9

A specific member of a class.

Question 10

Lifeline

Answer 10

In a sequence diagram, a lifeline is used to represent the time during which the object above it is able to interact with the other objects in the use case. An X marks the end of a lifeline.

Question 11

Message

Answer 11

An object-oriented command that tells an object to perform a certain method.

Question 12

Method

Answer 12

Defines specific tasks that an object must perform. Describes what and how an object does something.

Question 13

Object model

Answer 13

Describes objects, which combine data and processes. Object models are the end product of object-oriented analysis.

Question 14

Parent

Answer 14

In inheritance, a parent is the object from which the other object, the child, derives one or more attributes.

Question 15

Polymorphism

Answer 15

The concept that a message gives different meanings to different objects (e.g., a GOOD NIGHT message might produce different results depending on whether it is received by a child or the family dog).

Question 16

Relationships

Answer 16

Enable objects to communicate and interact as they perform the business functions and transactions required by a system. Relationships describe what objects need to know about each other, how objects respond to changes in other objects, and the effects of membership in classes, superclasses, and subclasses.

Question 17

State

Answer 17

An adjective that describes an object’s current status (e.g., a student could be a CURRENT, FUTURE, or PAST student).

Question 18

State transition diagram

Answer 18

Shows how an object changes from one state to another, depending on the events that affect the object.

Question 19

Subclass

Answer 19

A further division of objects in a class. Subclasses are more specific categories within a class.

Question 20

Superclass

Answer 20

A more generalized category to which objects may belong (e.g., a NOVEL class might belong to a superclass called BOOK).

Question 21

System boundary

Answer 21

Shows what is included and excluded from a system. Depicted by a shaded rectangle in use case diagrams.

Question 22

Use case

Answer 22

Represents the steps in a specific business function or process in UML.

Question 23

Use case description

Answer 23

A description in UML that documents the name of the use case, the actor, a description of the use case, a step-by-step list of the tasks required for successful completion, and other key descriptions and assumptions.