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QuoteRef: kentW_1978

topics > all references > ThesaHelp: references i-l



ThesaHelp:
references i-l
Group:
information
Topic:
limitations of artificial intelligence and cognitive science
Topic:
the effect of scale
Topic:
what is a computer
Group:
artificial intelligence
Topic:
problem of assigning names
Topic:
database as a model of reality
Topic:
entity-relationship database model
Topic:
using a computer as a communication/information medium
Topic:
symbolic representation
Topic:
entities
Topic:
problem of classifying information
Topic:
fundamental concepts such as type, attributes, relationships are all the same
Topic:
heterogeneous database
Topic:
database change management
Topic:
Thesa compiler and loader
Topic:
database schema
Topic:
kinds of relationships between data
Topic:
database record
Topic:
existence of database entities
Topic:
data type by lexical constraints
Topic:
objects as a set of attributes
Topic:
unique names
Topic:
facts as relationships between entities
Topic:
hypertext links
Group:
information retrieval
Topic:
alias names
Topic:
names defined by context
Topic:
using a description as a name
Topic:
objects without names
Topic:
renaming
Topic:
configuration management
Topic:
unique numeric names as surrogates
Topic:
names independent of objects
Topic:
graphs
Topic:
hypertext nodes
Topic:
database entities
Group:
naming
Topic:
private language argument for skepticism about meaning
Topic:
fact-based analysis for database design
Topic:
object and value equivalence
Group:
relationship information
Topic:
descriptive naming
Topic:
name of a relationship
Topic:
restricted and extended types
Topic:
roles of a relationship
Topic:
data type as a set of variables
Topic:
database consistency and reliability
Topic:
representing a relationship
Topic:
symmetry
Topic:
relationship as an object
Topic:
attribute-value pairs as information
Topic:
Thesa data model
Topic:
data as a named set of data objects
Topic:
value as an abstraction
Topic:
number representation
Group:
data type
Topic:
classification
Topic:
non-exclusive data type
Topic:
set construction
Topic:
set definition by extension or intension
Topic:
data type as a set of values
Group:
sets
Topic:
models of reality
Group:
database model

Reference

Kent, W., Data and reality, Amsterdam, North-Holland, 1978. Google

Notes

lines 100-continued at kentW_1978x

Quotations
vi ;;Quote: information may be too ambiguous and subjective to be embodied in a computer
vii ;;Quote: the real mystique of computers is their elaborate behavior from limited capabilities
viii ;;Quote: problems aggravated in computerized data bases since fewer conversations about the data
1 ;;Quote: a database models a small, finite subset of the real world
1 ;;Quote: database entities correspond to real entities
2 ;;Quote: information in a database is part of a communication process between people; with translations to and from formal languages
2 ;;Quote: resemblance between a database's contents and the original information depends on a common understanding of what references mean
3 ;;Quote: when are two things instances of the same thing
3 ;;Quote: in a bibliography, each book is an entity; in a library each copy of book is an entity
4 ;;Quote: a manual may be a 'book' in one library, but not a book in another (because it has a soft cover)
5 ;;Quote: the boundaries and extent of a classification can be arbitrary
6 ;;Quote: words are ambiguous because we must use a finite set to communicate a non-denumerable set of concepts
12 ;;Quote: in a mystery, the murderer and butler are separate entities; afterwards they are the same
13 ;;Quote: there is not a natural set of categories; a system defines its categories
13 ;;Quote: the same piece of information can be a category, an attribute, or a relationship; e.g., parents and children
13 ;;Quote: a person on leave may be an employee for benefits but not for payroll
17 ;;Quote: even though a database doesn't model reality, it is still useful
19 ;;Quote: a database models the way people process information about reality
25 ;;Quote: with an integrated database, new applications can borrow data already collected for other applications
25+ ;;Quote: changes in an integrated database are automatically made everywhere
28 ;;Quote: in traditional databases, data files and their descriptions are stored separately
31 ;;Quote: data which can be extracted from a system is not necessarily stored in the system
32 ;;Quote: the meaning of a field in a data record is usually implicit; e.g., joe smith and 95
32 ;;Quote: a database model is how users get to know and agree upon the meaning of data items
33 ;;Quote: list test for existence: if symbol on a list, then it exists
34 ;;Quote: syntactic checks for existence: a symbol is numeric, alphabetic, fixed length
34 ;;Quote: syntactic test of existence works for numbers, but not for strings, e.g., addresses
34 ;;Quote: correspondence between database model and real world is rather ad hoc
38 ;;Quote: can't represent a thing by its description; due to its relationships to other things
39 ;;Quote: representations should map one-to-one with real things
39 ;;Quote: linked representations and the existence of representations is the fundamental basis for representing information
40 ;;Quote: information associated with a representative must be asserted explicitly
41 ;;Quote: an information system is for entering and extracting information about entities
41 ;;Quote: a person has many names
42 ;;Quote: a name can be meaningless unless you know its category, e.g., Colt
43 ;;Quote: a person's name may have several correct spellings
43 ;;Quote: in Hawaii, people often use first few syllables of long last names
47 ;;Quote: qualified names resolves ambiguities by defining context; scope can be nested
49 ;;Quote: often things do not have individual, unique names, e.g., a nail
50 ;;Quote: qualified names, e.g., an employee's children, has problems of uniqueness, singularity, no qualifier, changing qualifier
53 ;;Quote: names do change
53 ;;Quote: how and how long should you handle references to old names or synonyms
54 ;;Quote: when versions are available, is it one object (the current version) or many versions
54 ;;Quote: a surrogate stands for a real thing within a system; its symbols can be different
55 ;;Quote: use objects and links to represent things; use character strings for description and communication
55 ;;Quote: with surrogates, symbolic names can be described independently of real objects
55 ;;Quote: a thing object is a node on a graph; its label may be changed, deleted, or duplicated
56 ;;Quote: names can have different relationships to things; e.g., legal name, maiden name, descriptive name
56 ;;Quote: a particular day is a single concept, but its names come in various forms
56 ;;Quote: by separating objects and names can have different types of names for the same thing, e.g., legal name and employee number
56 ;;Quote: with surrogates, can avoid confusing assertions about real things, about names, and about relationships
57 ;;Quote: in ordinary communication, the ability to stretch and modify meanings is essential
59 ;;Quote: a fact consists of identifying a relationship between surrogates
59 ;;Quote: surrogates are globally unique
59 ;;Quote: surrogates are information free; they do not imply additional information
59 ;;Quote: surrogates are atomic, unstructured units
59 ;;Quote: with surrogates, a fact is an association of surrogates that correspond to objects in the fact
60 ;;Quote: when are two names the same; equality testing by match, surrogate, list, and procedural
60 ;;Quote: in the match test, two names are the same only if they are identical
60 ;;Quote: in the surrogate test, two names are the same only if the reference the same surrogate
60 ;;Quote: in the list test, two names are the same if they occur on the same list of synonyms
60 ;;Quote: in the procedural test, two names are the same if a procedure says so
60 ;;Quote: if aliases are supported, which name is returned in answering a question
63 ;;Quote: almost everything in an information system is a relationship
63 ;;Quote: a relationship is a set of associations between things for a given reason
63 ;;Quote: the name of a relationship is a statement of a reason for an association
63 ;;Quote: an important part of a relationship is the reason for an association
64 ;;Quote: a relationship could be between an object and a set of objects, but Kent does not pursue this option
64 ;;Quote: a domain is the set of things that can occur in a given role of a relationship
65 ;;Quote: a relationship is specified by a set of roles; the degree of a relationship is the set's size
65 ;;Quote: a database model should allow arbitrary combinations of constraints on relationships
67 ;;Quote: a role can be constrained to a single domain, several domains, or unconstrained
66 ;;Quote: a relationship direction can map one to one (simple) or one to many (complex)
68 ;;Quote: even though both roles of a relationship can have the same domain, a thing may or may not be related to itself
68 ;;Quote: a relationship may be optional or mandatory for all objects in a domain
68 ;;Quote: a system may allow only one relationship between each pair of domains
70 ;;Quote: a relationship may be transitive
70 ;;Quote: a relationship may be symmetric; but such relationships are seldom supported
71 ;;Quote: a relationship can be anti-symmetric
71 ;;Quote: a relationship may be composed from other relationships
71 ;;Quote: a relationship may be a subset of another relationship
71 ;;Quote: a one-many relationship may have a maximum size
72 ;;Quote: a relationship instance may have attributes or relationships of its own
72 ;;Quote: a system should be able to list the relationships for an object or a pair of objects
72 ;;Quote: a relationship may have no name, one name, or a name for each direction
75 ;;Quote: every computable procedure represents a relationships
75 ;;Quote: an ordering between objects is a computed relationship
76 ;;Quote: even though uncle is derived from father and brother, sometimes only know the uncle relationship
76 ;;Quote: computed relationships are not modifiable; instances can be infinite, without attributes or relations
77 ;;Quote: much of information is the attributes of things
79 ;;Quote: attributes and relationships are the same kind of information
80 ;;Quote: a value, e.g., 'six feet', is an entity with many representations
82 ;;Quote: categories and attributes are the same kind of information
85 ;;Quote: things are classified into types for naming scope, validity constraints, and relationship domains; groups are mutually exclusive
88 ;;Quote: types should be non-exclusive
90 ;;Quote: minimal set predicate: the set of things having relationship x to object y
90 ;;Quote: a type is the abstract idea of a set (its intension), not its contents
90 ;;Quote: traditional set theory defines sets by their contents -- not relevant to types
91 ;;Quote: a set can be object that is related to its members
93 ;;Quote: a model or world view is a basic system of constructs used to describe reality
93 ;;Quote: a model shapes and limits our view of reality; it can distort reality to make it fit the view
94 ;;Quote: existing database models are highly structured, rigid, and simplistic
95 ;;Quote: corporations are defining their database schemas; this will be a major asset
97 ;;Quote: some authors equate signs with information, but lose the meaning of that information
98 ;;Quote: hierarchical, relational, and network models are variations of the data record model


Related Topics up

ThesaHelp: references i-l (342 items)
Group: information   (46 topics, 1160 quotes)
Topic: limitations of artificial intelligence and cognitive science (64 items)
Topic: the effect of scale (17 items)
Topic: what is a computer (62 items)
Group: artificial intelligence   (14 topics, 509 quotes)
Topic: problem of assigning names (25 items)
Topic: database as a model of reality (25 items)
Topic: entity-relationship database model (22 items)
Topic: using a computer as a communication/information medium (32 items)
Topic: symbolic representation (26 items)
Topic: entities (20 items)
Topic: problem of classifying information (42 items)
Topic: fundamental concepts such as type, attributes, relationships are all the same (37 items)
Topic: heterogeneous database (6 items)
Topic: database change management (12 items)
Topic: Thesa compiler and loader (23 items)
Topic: database schema (29 items)
Topic: kinds of relationships between data (16 items)
Topic: database record (22 items)
Topic: existence of database entities (19 items)
Topic: data type by lexical constraints (15 items)
Topic: objects as a set of attributes (39 items)
Topic: unique names (58 items)
Topic: facts as relationships between entities (22 items)
Topic: hypertext links (45 items)
Group: information retrieval   (25 topics, 674 quotes)
Topic: alias names (39 items)
Topic: names defined by context (36 items)
Topic: using a description as a name (21 items)
Topic: objects without names (7 items)
Topic: renaming (10 items)
Topic: configuration management (25 items)
Topic: unique numeric names as surrogates (67 items)
Topic: names independent of objects (34 items)
Topic: graphs (18 items)
Topic: hypertext nodes (19 items)
Topic: database entities (12 items)
Group: naming   (32 topics, 789 quotes)
Topic: private language argument for skepticism about meaning (34 items)
Topic: fact-based analysis for database design (15 items)
Topic: object and value equivalence (60 items)
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Topic: descriptive naming (29 items)
Topic: name of a relationship (5 items)
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Topic: roles of a relationship (8 items)
Topic: data type as a set of variables (11 items)
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Topic: representing a relationship (28 items)
Topic: symmetry (11 items)
Topic: relationship as an object (6 items)
Topic: attribute-value pairs as information (57 items)
Topic: Thesa data model (58 items)
Topic: data as a named set of data objects (22 items)
Topic: value as an abstraction (25 items)
Topic: number representation (16 items)
Group: data type   (34 topics, 730 quotes)
Topic: classification (65 items)
Topic: non-exclusive data type (16 items)
Topic: set construction (20 items)
Topic: set definition by extension or intension (18 items)
Topic: data type as a set of values (20 items)
Group: sets   (7 topics, 148 quotes)
Topic: models of reality (33 items)
Group: database model   (15 topics, 316 quotes)

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