Deck 8: Structuring System Data Requirements

Question 1

An entity instance is a single occurrence of an entity type.

Answer 1

True

Question 2

Use a verb or verb phrase to name an entity.

Answer 2

False

Question 3

An ellipse represents an entity on an entity-relationship diagram.

Answer 3

False

Question 4

An entity is a person,place,object,event,or concept in the user environment about which the organization wishes to maintain data.

Question 5

The names of data stores on primitive-level data flow diagrams often correspond to the names of data entities in entity-relationship diagrams.

Question 6

A primary key should be null.

Question 7

Social security number,last name,and first name are entity types.

Question 8

Employee identification number,name,address,and skill are attributes.

Question 9

The purpose of the conceptual data model is to show as many rules about the meaning and interrelationships among data as possible.

Question 10

Processes,rather than data,are the most complex aspects of many modern information systems.

Question 11

An order number is a good example of a candidate key.

Question 12

A faculty identification number can serve as an identifier.

Question 13

The top-down approach to data modeling derives the business rules for a data model from an intimate understanding of the nature of the business.

Question 14

Book,supplier,and state are entity types.

Question 15

The characteristics of data captured during data modeling are crucial in the design of databases,programs,computer screens,and printed reports.

Question 16

A deliverable from conceptual data modeling is a set of entries about data objects to be stored in the project dictionary or repository.

Question 17

The primary deliverable from the conceptual data modeling step within the analysis phase is an entity-relationship diagram.

Question 18

The bottom-up approach to data modeling derives a data model by reviewing specific business documents.

Question 19

In order to determine the integrity rules,minimum and maximum cardinality,and time dimensions of data,an analyst might ask,"Are values for data characteristics limited in any way?"

Question 20

A true data entity will have many possible instances,each with a distinguishing characteristic,as well as one or more other descriptive pieces of data.

Question 21

Cardinality is the number of instances of entity B that can (or must)be associated with each instance of entity A.

Question 22

An identifier is a candidate key that has been selected as the unique,identifying characteristic for an entity type.

Question 23

A plural relationship is a relationship that the data modeler chooses to model as entity type.

Question 24

Relationships are labeled with verb phrases.

Question 25

A join is an association between the instances of one or more entity types that is of interest to the organization.

Question 26

The minimum cardinality of a relationship is the minimum number of instances of entity B that may be associated with each instance of entity A.

Question 27

A unary relationship is the most common type of relationship encountered in data modeling.

Question 28

A multivalued attribute is an attribute that may take on more than one value for each entity instance.

Question 29

The goal of conceptual data modeling is to capture as much of the meaning of data as possible.

Question 30

A ternary relationship is the equivalent of three binary relationships.

Question 31

Analysts should substitute single-attribute surrogate keys for large composite keys.

Question 32

On an entity relationship diagram,total specialization is shown by a single line from the supertype to the subtype.

Question 33

A ternary relationship is a relationship between the instances of one entity type.

Question 34

When selecting an identifier,one should choose a candidate key that will not change its value over the life of each instance of the entity type.

Question 35

Referencing an employee entity,an employee's skills are a multivalued attribute.

Question 36

A repeating group is a set of two or more multivalued attributes that are logically related.

Question 37

Conceptual data modeling for an Internet-based electronic commerce application differs significantly from the process followed when analyzing the data needs for other types of applications.

Question 38

One way to handle repeating data within an entity is to separate the repeating data into another entity,called a weak entity.

Question 39

Analysts should use intelligent keys as identifiers.

Question 40

A relationship must be turned into an associative entity when the associative entity has other relationships with entities besides the relationship that caused its creation.

Question 41

Domains are constraints on valid values for attributes.

Question 42

An E-R model with attributes is prepared during:

A)design
B)project identification and selection
C)analysis
D)project initiation and planning

Question 43

Triggers are constraints on valid values for attributes.

Question 44

Domains are other business rules that protect the validity of attribute values.

Question 45

Some systems developers believe that a data model is the most important part of the statement of information system requirements because:

A)the characteristics of data captured during data modeling are crucial in the design of databases,programs,computer screens,and printed reports
B)data rather than processes are the most complex aspects of many modern information systems and thus require a central role in structuring system requirements
C)the characteristics about data are reasonably permanent
D)all of the above

Question 46

The three main constructs of the entity-relationship modeling notation include each of the following except:

A)data entities
B)data flows
C)relationships
D)attributes

Question 47

Universal data models and industry-specific data models are two types of packaged conceptual data models.

Question 48

Business rules are specifications that preserve the integrity of the physical data model.

Question 49

Referential integrity constraints are rules concerning the relationships between entity types.

Question 50

Process,logic,and data model descriptions of a system must be consistent and complete because:

A)they each describe different but complementary views of the same information system
B)they are prepared during the analysis phase
C)they are constructed in parallel by separate analyst teams
D)programming tasks require the integration of the information contained in the diagrams

Question 51

Conceptual data modeling is typically done in parallel with other requirements analysis and structuring steps during:

A)logical design
B)physical design
C)analysis
D)implementation

Question 52

Which of the following is a true statement?

A)Data characteristics are dynamic.
B)A data model explains the transient form of an organization.
C)An information system design based on a data orientation,rather than a process or logic orientation,should have a longer useful life.
D)Data flow paths are permanent.

Question 53

Triggering operations are other business rules that protect the validity of attribute values.

Question 54

The most common format used for data modeling is:

A)state-transition diagramming
B)entity-relationship diagramming
C)process modeling
D)decision table diagramming

Question 55

Entity integrity means each instance of an entity type must have a unique identifier that is not null.

Question 56

During requirements structuring:

A)an E-R model represents conceptual data requirements for a particular system
B)the conceptual E-R data model is refined before it is translated into a logical format from which database definition and physical database design are done
C)an enterprise-wide data model with very broad categories of data and little detail is prepared
D)a specific E-R model is built to help explain the scope of a particular systems analysis and design effort

Question 57

The data modeling perspective that derives the business rules for a data model from an intimate understanding of the nature of the business,rather than from any specific information requirements in screens,reports,or business forms,is referred to as the:

A)top-down approach
B)bottom-up approach
C)overview approach
D)business approach

Question 58

A detailed,logical representation of the entities,associations,and data elements for an organization or business area defines:

A)entity-relationship diagram
B)conceptual model
C)entity-relationship model
D)data flow diagram

Question 59

A person,place,object,event,or concept in the user environment about which the organization wishes to maintain data refers to a(n):

A)attribute
B)data element
C)relationship
D)entity

Question 60

The primary deliverable from the conceptual modeling step within the analysis phase is a(n):

A)state-transition diagram
B)E-R diagram
C)context data flow diagram
D)decision tree

Question 61

Which of the following specifies that an entity instance can simultaneously be a member of two (or more)subtypes?

A)total specialization rule
B)partial specialization rule
C)disjoint rule
D)overlap rule

Question 62

A subgrouping of the entities in an entity type that is meaningful to the organization and that shares common attributes or relationships distinct from other subgroupings best defines:

A)child node
B)disjoined entity
C)subtype
D)supertype

Question 63

An attribute (or combination of attributes)that uniquely identifies each instance of an entity type defines:

A)data element occurrence
B)trigger
C)candidate key
D)gerund

Question 64

If each employee can have more than one skill,then SKILL is referred to as a:

A)gerund
B)multivalued attribute
C)nonexclusive attribute
D)repeating attribute

Question 65

When selecting an identifier,one should:

A)use intelligent keys
B)use large composite keys instead of single-attribute surrogate keys
C)choose a candidate key that will not change its value over the life of each instance of the entity type
D)choose a candidate key such that for each instance of the entity,the attribute is guaranteed to have valid values or is null

Question 66

If STUDENT and COURSE participate in a relationship,their relationship is a(n):

A)unary relationship
B)binary relationship
C)ternary relationship
D)extraordinary relationship

Question 67

A relationship that the data modeler chooses to model as an entity type best defines:

A)recursive relationship
B)associative entity
C)domain
D)complex relationship

Question 68

A simultaneous relationship among instances of three entity types is a:

A)unary relationship
B)binary relationship
C)ternary relationship
D)multiple occurrence

Question 69

A set of two or more multivalued attributes that are logically related defines:

A)relationship
B)gerund
C)repeating group
D)class

Question 70

The number of instances of entity B that can (or must)be associated with each instance of entity A refers to:

A)cardinality
B)domain
C)ternary occurrence
D)participation level

Question 71

A collection of entities that share common properties or characteristics defines:

A)entity type
B)entity instance
C)entity occurrence
D)entity collection

Question 72

For each entity,the name of the identifier is:

A)identified by using a double-lined ellipse
B)underlined on an E-R diagram
C)bold on an E-R diagram
D)written in all capital letters on an E-R diagram

Question 73

An association between the instances of one or more entity types that is of interest to the organization best defines:

A)occurrence
B)relationship
C)coupling
D)cardinality

Question 74

If entity B is a mandatory participant,then:

A)the minimum cardinality of the relationship is two
B)the minimum cardinality of the relationship cannot be defined
C)the minimum cardinality of the relationship is one
D)the minimum cardinality of the relationship is optional

Question 75

The minimum number of instances of entity B that may be associated with each instance of entity A defines the:

A)degree of the relationship
B)minimum cardinality of the relationship
C)maximum cardinality of the relationship
D)domain of the relationship

Question 76

A single occurrence of an entity type defines:

A)entity instance
B)entity appearance
C)attribute
D)data element

Question 77

A named property or characteristic of an entity that is of interest to the organization defines:

A)attribute
B)relationship
C)instance
D)gerund

Question 78

Which of the following specifies that each entity instance of the supertype must be a member of some subtype in the relationship?

A)total specialization rule
B)partial specialization rule
C)disjoint rule
D)overlap rule

Question 79

A candidate key that has been selected as the unique,identifying characteristic for an entity type is called a(n):

A)attribute
B)identifier
C)secondary key
D)gerund

Question 80

An attribute that may take on more than one value for each entity instance is referred to as a:

A)gerund
B)multivalued attribute
C)nonexclusive attribute
D)supertype