Group:
hypertext
Topic:
abstraction by resemblance
Topic:
database change management
Topic:
definition by example
Topic:
design for change
Topic:
disorientation in a user interface
Topic:
file
Topic:
hypertext as unstructured information
Topic:
language flexibility
Topic:
limitations of hierarchical structures
Topic:
non-constraining system
Topic:
non-hierarchical classification and multiple classification
Topic:
personal information
Topic:
problem of classifying information
Topic:
problems with fragmentation in hypertext
Topic:
problems with disorientation in hypertext
Topic:
problems with information retrieval
Topic:
schemas for hypertext
Topic:
semi-structured text
Topic:
text markup and structured text
Topic:
size of hypertext nodes
Topic:
XML data type
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Summary
Data may be loosely structured. While computers work best with precisely defined data (e.g., a pair of 64-bit floating point real numbers aligned on a quad-word boundary), real-world data is often ill-defined. Text is the canonical example. For example, books are often divided into chapters, chapters into sections, and sections into paragraphs. These divisions differ between books and may vary within a single book.
Another example is personal address books. An address book may be carefully alphabetized with separate entries for phone number, address, and birth date, or it may be scraps of paper with names, phone numbers, and addresses intermingled.
What is the proper representation of ill-defined data? Text is good enough for many applications. When needed, search and pattern matching can extract data from the text, especially if manual processing can resolve ambiguities. Keyword-value pairs provides a simple markup for non-hierarchical text, while XML can represent arbitrary combinations of attributes, hierarchy, and text. (cbb 8/06)
Subtopic: database vs. text 
| Quote: databases have either well-defined record structures, or unstructured text files [»akscRM5_1984]
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Subtopic: groups vs links
| Quote: structure arises out of the grouping of similar items and intergroup relationships; and not from hypertext links between items [»kaplSJ7_1990]
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Subtopic: file vs dynamic structures
| Quote: users of file systems must keep track of files and the cluttered relationships between them [»nelsTH1_1988]
| | Quote: a personal information system must allow free format text, dynamically defined structure, and arbitrary report formats [»kaplSJ7_1990]
| | Quote: the information world should be without files; i.e., interconnections, multiple versions, and multiple views are easily visible [»nelsTH12_1986]
|
Subtopic: arbitrary structures
| Quote: all structures and hierarchies are totally arbitrary [»nelsTH_1974]
| | Quote: with computers, totally arbitrary structures are possible; don't have to be in sequence [»nelsTH_1974]
| | Quote: the world needs a universal form of storage which does not slant the data [»nelsTH12_1986]
| | Quote: evolutionary list file for ill-defined information that changes [»nelsTH8_1965]
|
Subtopic: serial file
| Quote: the serial file is the fundamental data structure; explored sequentially
|
Subtopic: semi-structure messages
| Quote: semistructured messages increase flexibility by allowing nonstandard communications [»maloTW4_1987]
| | Quote: an electronic mail message consists of a header of formatted data and an unstructured body [»tsicD1_1983]
| | Quote: unstructured information by 'comments' field [»kentW_1978]
| | Quote: Partially Shared Views (PSV) consists of shared object types, translation rules between object types, and default translations via shared "parent" types [»leeJ1_1990]
|
Subtopic: specialization hierarchy
| Quote: Agenda categories form a hierarchy; items implicitly assigned to their parents [»kaplSJ7_1990]
| | Quote: automatic translation is practical if groups share a specialization hierarchy; helps preserve the meaning of messages [»leeJ1_1990]
|
Subtopic: predicate-based sets
| Quote: predicate data model: identify subset of a database, a set of records, by a predicate [»giffDK12_1985]
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Subtopic: hypertext
| Quote: Hypertext as independent, unstructured documents or as semantic links for graph-traversal; pattern-matching vs. browsing [»frisME7_1988]
| | Quote: Hypertext of structured information for querying and unstructured information [»clifC9_1988]
|
Subtopic: frame structures
Quote: schemas (a structure of frames) more flexible than types for databases
[»akscRM5_1984]
|
Related Topics
Group: hypertext (44 topics, 786 quotes)
Topic: abstraction by resemblance (13 items)
Topic: database change management (12 items)
Topic: definition by example (26 items)
Topic: design for change (76 items)
Topic: disorientation in a user interface (13 items)
Topic: file (22 items)
Topic: hypertext as unstructured information (4 items)
Topic: language flexibility (34 items)
Topic: limitations of hierarchical structures (10 items)
Topic: non-constraining system (25 items)
Topic: non-hierarchical classification and multiple classification (16 items)
Topic: personal information (41 items)
Topic: problem of classifying information (42 items)
Topic: problems with fragmentation in hypertext (13 items)
Topic: problems with disorientation in hypertext (18 items)
Topic: problems with information retrieval (51 items)
Topic: schemas for hypertext (7 items)
Topic: semi-structured text (17 items)
Topic: text markup and structured text (25 items)
Topic: size of hypertext nodes (8 items)
Topic: XML data type
(22 items)
|
