This Document Contains Chapters 8 and Appendix Chapter 8 Structuring System Data Requirements 1) The characteristics of data captured during data modeling are crucial in the design of databases, programs, computer screens, and printed reports. Answer: True 2) Processes, rather than data, are the most complex aspects of many modern information systems. Answer: False 3) The purpose of the conceptual data model is to show as many rules about the meaning and interrelationships among data as possible. Answer: True 4) The names of data stores on primitive-level data flow diagrams often correspond to the names of data entities in entity-relationship diagrams. Answer: True 5) The primary deliverable from the conceptual data modeling step within the analysis phase is an entity-relationship diagram. Answer: True 6) A deliverable from conceptual data modeling is a set of entries about data objects to be stored in the project dictionary or repository. Answer: True 7) 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. Answer: True 8) The bottom-up approach to data modeling derives a data model by reviewing specific business documents. Answer: True 9) 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?" Answer: True 10) An entity is a person, place, object, event, or concept in the user environment about which the organization wishes to maintain data. Answer: True 11) Social security number, last name, and first name are entity types. Answer: False 12) Book, supplier, and state are entity types. Answer: True 13) An ellipse represents an entity on an entity-relationship diagram. Answer: False 14) Use a verb or verb phrase to name an entity. Answer: False 15) 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. Answer: True 16) An entity instance is a single occurrence of an entity type. Answer: True 17) Employee identification number, name, address, and skill are attributes. Answer: True 18) An order number is a good example of a candidate key. Answer: True 19) A faculty identification number can serve as an identifier. Answer: True 20) A primary key should be null. Answer: False 21) An identifier is a candidate key that has been selected as the unique, identifying characteristic for an entity type. Answer: True 22) 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. Answer: True 23) Analysts should use intelligent keys as identifiers. Answer: False 24) Analysts should substitute single-attribute surrogate keys for large composite keys. Answer: True 25) Referencing an employee entity, an employee's skills are a multivalued attribute. Answer: True 26) One way to handle repeating data within an entity is to separate the repeating data into another entity, called a weak entity. Answer: True 27) A multivalued attribute is an attribute that may take on more than one value for each entity instance. Answer: True 28) A repeating group is a set of two or more multivalued attributes that are logically related. Answer: True 29) A join is an association between the instances of one or more entity types that is of interest to the organization. Answer: False 30) Relationships are labeled with verb phrases. Answer: True 31) The goal of conceptual data modeling is to capture as much of the meaning of data as possible. Answer: True 32) A ternary relationship is a relationship between the instances of one entity type. Answer: False 33) A unary relationship is the most common type of relationship encountered in data modeling. Answer: False 34) A ternary relationship is the equivalent of three binary relationships. Answer: False 35) Cardinality is the number of instances of entity B that can (or must) be associated with each instance of entity A. Answer: True 36) 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. Answer: True 37) A plural relationship is a relationship that the data modeler chooses to model as entity type. Answer: False 38) 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. Answer: True 39) On an entity relationship diagram, total specialization is shown by a single line from the supertype to the subtype. Answer: False 40) 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. Answer: False 41) Universal data models and industry-specific data models are two types of packaged conceptual data models. Answer: True 42) Entity integrity means each instance of an entity type must have a unique identifier that is not null. Answer: True 43) Referential integrity constraints are rules concerning the relationships between entity types. Answer: True 44) Triggers are constraints on valid values for attributes. Answer: False 45) Domains are other business rules that protect the validity of attribute values. Answer: False 46) Business rules are specifications that preserve the integrity of the physical data model. Answer: False 47) Domains are constraints on valid values for attributes. Answer: True 48) Triggering operations are other business rules that protect the validity of attribute values. Answer: True 49) 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 Answer: D 50) 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. Answer: C 51) The most common format used for data modeling is: A) state-transition diagramming B) entity-relationship diagramming C) process modeling D) decision table diagramming Answer: B 52) 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 Answer: A 53) 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 Answer: C 54) 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 Answer: A 55) An E-R model with attributes is prepared during: A) design B) project identification and selection C) analysis D) project initiation and planning Answer: C 56) 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 Answer: B 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 Answer: A 58) 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 Answer: B 59) 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 Answer: C 60) 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 Answer: D 61) A collection of entities that share common properties or characteristics defines: A) entity type B) entity instance C) entity occurrence D) entity collection Answer: A 62) A single occurrence of an entity type defines: A) entity instance B) entity appearance C) attribute D) data element Answer: A 63) A named property or characteristic of an entity that is of interest to the organization defines: A) attribute B) relationship C) instance D) gerund Answer: A 64) 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 Answer: C 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 Answer: C 66) 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 Answer: B 67) 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 Answer: B 68) 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 Answer: B 69) 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 Answer: B 70) A set of two or more multivalued attributes that are logically related defines: A) relationship B) gerund C) repeating group D) class Answer: C 71) 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 Answer: B 72) 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 Answer: B 73) A simultaneous relationship among instances of three entity types is a: A) unary relationship B) binary relationship C) ternary relationship D) multiple occurrence Answer: C 74) 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 Answer: A 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 Answer: B 76) 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 Answer: C 77) 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 Answer: B 78) 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 Answer: C 79) 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 Answer: A 80) 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 Answer: D 81) Which of the following specifies that an entity instance of the supertype is allowed not to belong to any subtype? A) total specialization rule B) partial specialization rule C) disjoint rule D) overlap rule Answer: B 82) Which of the following specifies that if an entity instance of the supertype is a member of one subtype it cannot simultaneously be a member of any other subtype? A) total specialization rule B) partial specialization rule C) disjoint rule D) overlap rule Answer: C 83) Specifications that preserve the integrity of the logical data model are: A) requirements specifications B) integrity restrictions C) business limitations D) business rules Answer: D 84) Which of the following addresses the rules concerning the relationships between entity types? A) referential integrity constraints B) triggering operations C) entity integrity D) domains Answer: A 85) Which of the following specifies that each instance of an entity type must have a unique identifier that is not null? A) referential integrity constraints B) triggering operations C) entity integrity D) domains Answer: C 86) Which of the following refers to the set of all data types and values that an attribute can assume? A) referential integrity constraints B) triggering operations C) entity integrity D) domains Answer: D 87) Which of the following refers to an assertion or rule that governs the validity of data manipulation operations such as insert, update, and delete? A) referential integrity constraints B) triggering operations C) entity integrity D) domains Answer: B 88) The set of all data types and ranges of values that an attribute can assume defines: A) cardinality B) constraint set C) domain D) reference set Answer: C 89) An assertion or rule that governs the validity of data manipulation operations such as insert, update, and delete is: A) triggering operation B) entity integrity C) referential integrity constraints D) domains Answer: A 90) The data manipulation operation (insert, delete, or update) that initiates the operation is called a(n): A) condition B) action C) user rule D) event Answer: D 91) A concise statement of the business rule to be enforced by the triggering operation refers to: A) user rule B) condition C) action D) event Answer: A 92) The condition that causes the operation to be triggered: A) condition B) action C) entity name D) user rule Answer: A 93) All of the following are benefits of database patterns and packaged data models EXCEPT: A) purchased models are proven from extensive experience B) systems analysis is facilitated C) purchased models are very specific D) purchased models anticipate future needs Answer: C 94) A ________ is a detailed model that captures the overall structure of organizational data that is independent of any database management system or other implementation considerations. Answer: conceptual data model 95) An ________ is a detailed, logical representation of the entities, associations, and data elements for an organization or business area. Answer: entity-relationship data model 96) An ________ is a single occurrence of an entity type. Answer: entity instance 97) An ________ is a named property or characteristic of an entity that is of interest to the organization. Answer: attribute 98) An ________ is a candidate key that has been selected as the unique, identifying characteristic for an entity type. Answer: identifier 99) A ________ is an attribute that may take on more than one value for each entity instance. Answer: multivalued attribute 100) A ________ is a set of two or more multivalued attributes that are logically related. Answer: repeating group 101) A ________ is an association between the instances of one or more entity types that is of interest to the organization. Answer: relationship 102) A ________ is a relationship between the instances of one entity type. Answer: unary relationship 103) A ________ is a relationship between instances of two entity types. Answer: binary relationship 104) A ________ is a simultaneous relationship among instances of three entity types. Answer: ternary relationship 105) ________ refers to the number of instances of entity B that can (or must) be associated with each instance of entity A. Answer: Cardinality 106) An ________ is an entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship between those entity instances. Answer: associative entity 107) A ________ is 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. Answer: subtype 108) A ________ is a generic entity type that has a relationship with one or more subtypes. Answer: supertype 109) The ________ specifies that if an entity instance of the supertype is a member of one subtype, it cannot simultaneously be a member of any other subtype. Answer: disjoint rule 110) The ________ specifies that an entity instance can simultaneously be a member of two (or more) subtypes. Answer: overlap rule 111) The ________ specifies that an entity instance of the supertype is allowed not to belong to any subtype. Answer: partial specialization rule 112) A ________ is the set of all data types and range of values that an attribute can assume. Answer: domain 113) A ________ is an assertion or rule that governs the validity of data manipulation operations such as insert, update, and delete. Answer: triggering operation 114) Define the following key data modeling terms: entity, attribute, relationship, degree, cardinality, and associative entity. Answer: An entity is a person, place, object, event, or concept in the user environment about which the organization wishes to collect and maintain data. An attribute is a named property or characteristic of an entity that is of interest to the organization. A relationship is an association between the instances of one or more entity types that is of interest to the organization. Degree defines the number of entity types that participate in a relationship. Cardinality specifies the number of instances of entity B that can (or must) be associated with each instance of entity A. An associative entity is a many-to-many (or one-to-one) relationship that the data modeler chooses to model as an entity type with several associated one-to-many relationships with other entity types. 115) Discuss unary, binary, and ternary relationships. Provide an example of each. Answer: The number of entity types participating in a relationship defines the degree of the relationship. The most common relationships are unary, binary, and ternary. A unary relationship is a relationship between the instances of one entity type. An example of this type of relationship is of the "person" entity. One person (or instance) can be married to another person (or instance). The binary relationship is a relationship between instances of two entity types. An example of this relationship is of a supplier and part. The binary relationship is the most common type of relationship encountered in data modeling. The ternary relationship is a simultaneous relationship among instances of three entity types. An example is a supplier shipping a part to a warehouse. 116) Contrast data modeling to process modeling and logic modeling. Answer: Data modeling, process modeling, and logic modeling provide complimentary views of the system. Data modeling focuses on the data that must be stored by the system. Process modeling graphically represents the processes that capture, distribute, and store data between a system and its environment. Logic modeling represents the internal structure and functionality of the system. 117) What are multivalued attributes and repeating groups? Provide an example of each. Answer: A multivalued attribute is an attribute that may assume more than one value for each entity instance. A repeating group is a related set of multivalued attributes. Using a student and the courses she takes as an example, the course number, name, and grade are multivalued attributes and repeat for each course that the student takes. 118) What is the role of CASE in conceptual modeling? What information is placed in the CASE repository during conceptual modeling? Answer: During conceptual modeling, CASE tools maintain E-R diagrams as a visual depiction of structured data requirements and link objects on E-R diagrams to corresponding descriptions in the CASE repository. Although the actual list of data elements varies, information about entities, attributes, and relationships is maintained in the CASE repository. 119) What is a triggering operation? What components are included? Provide an example. Answer: A triggering operation is an assertion or rule that governs the validity of data manipulation operations such as insert, update, and delete. A triggering operation includes a user rule, event, entity name, condition, and action. An example is an attempt to order an item that is not currently in stock. User rule: ORDER Quantity may not exceed PRODUCT In-Stock-Quantity Event: Insert Entity Name: ORDER Condition: ORDER Quantity > PRODUCT In-Stock-Quantity Action: Reject the insert transaction 120) Define domains for the following attributes: GPA, rank, and age. Answer: A student's GPA is numeric with two decimal places, ranges and allows values from 0 to 4.00, is not unique, and allows null values. (An entering freshman would not have a GPA until after her first semester.) Student rank is a numeric field, does not allow null values, and is not unique. Assuming all students are undergraduate students, the field contains values, ranging from 1 to 4. 121) Assume you work for Technology Central, an organization that provides on-site technology seminars for various companies. Identify at least four entities that your company would track. Build a conceptual model. Answer: Technology Central tracks information about its courses, staff, locations, and students. The organization needs to identify which courses are offered at certain locations and which instructors are teaching these classes. The company also needs to associate students with a particular course offered at a particular location. 122) Briefly identify four important business rules for supertype/subtype relationships. Answer: Total specialization, partial specialization, disjoint, and overlap are four business rules for supertype/subtype relationships. The total specialization rule specifies that each entity instance of the supertype must be a member of some subtype in the relationship. The partial specialization rule specifies that an entity instance of the supertype is allowed not to belong to any subtype. The disjoint rule specifies that if an entity instance of the supertype is a member of one subtype, it cannot simultaneously be a member of any other subtype. The overlap rule specifies that an entity instance can simultaneously be a member of two (or more) subtypes. Chapter 8 Appendix: Objected-Oriented Analysis and Design: Object Modeling-Class Diagrams 1) An object class is a logical grouping of objects that have the same attributes and behaviors. Answer: True 2) Operations provide an external interface to a class. Answer: True 3) The technique of hiding the internal implementation details of an object from its external view is called incorporation. Answer: False 4) On a class diagram, an association is signified by a double-ended arrow that connects the participating object classes. Answer: False 5) An operation is an indication of how many objects participate in a given relationship. Answer: False 6) Multiplicity indicates how many objects participate in a given relationship. Answer: True 7) An aggregation expresses a Part-of relationship between a component object and an aggregate object. Answer: True 8) An aggregation expresses a Part-of relationship between a component object and an aggregate object. Answer: True 9) An entity that has a well-defined role in the application domain and has state, behavior, and identity characteristics defines: A) object B) attribute C) actor D) class Answer: A 10) Which of the following encompasses an object's properties and the values those properties have? A) behavior B) class C) state D) encapsulation Answer: C 11) Which of the following represents how an object acts and reacts? A) behavior B) class C) state D) encapsulation Answer: A 12) In UML, a class is represented by: A) a rectangle with three compartments separated by horizontal lines B) a circle in which the activity name is recorded C) a double-lined ellipse in which the activity name is recorded D) a diamond in which the activity name is recorded Answer: A 13) Showing the static structure of an object-oriented model — the object classes, their internal structure, and the relationships in which they participate — is the purpose of a: A) class diagram B) sequence diagram C) collaboration diagram Answer: A 14) Which of the following provides an external interface to a class? A) constructor B) operation C) view D) association Answer: B 15) The technique of hiding the internal implementation details of an object from its external view is called: A) disassociation B) encryption C) generalization Answer: C 16) 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 Answer: B 17) An entity that has a well-defined role in the application domain and has state, behavior, and identity characteristics defines: A) object B) attribute C) actor D) class Answer: A 18) Which of the following encompasses an object's properties and the values those properties have? A) behavior B) class C) state D) encapsulation Answer: C 19) Which of the following represents how an object acts and reacts? A) behavior B) class C) state D) encapsulation Answer: A 20) Which of the following provides an external interface to a class? A) constructor B) operation C) view D) association Answer: B 21) The technique of hiding the internal implementation details of an object from its external view is called: A) disassociation B) encryption C) encapsulation D) generalization Answer: C 22) ________ is the technique of hiding the internal implementation details of an object from its external view. Answer: Encapsulation 23) An ________ is a relationship between object classes. Answer: association 24) ________ is an indication of how many objects participate in a given relationship. Answer: Multiplicity 25) An ________ is a class that has no direct instances, but whose descendants may have direct instances. Answer: abstract class 26) ________ is a part-of relationship between a component object and an aggregate object. Answer: Aggregation 27) What is an operation? Briefly describe three types of operations. Answer: An operation is a function or a service that is provided by all the instances of a class. Constructor, query, and update are the three types of operations. A constructor operation creates a new instance of a class. A query operation accesses the state of an object but does not alter its state. An update operation alters the state of an object. Test Bank for Modern Systems Analysis and Design Jeffrey A. Hoffer, Joey George, Joseph S. Valacich, Joe Valacich, Jeffrey Slater 9780132991308, 9780134204925, 9780135172759, 9780136088219
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