Topic: taxonomy

topics > philosophy > Group: formalism

data type
type inheritance

abstraction by common attributes
decomposition of a system into levels
definition by example
hierarchical structures
non-hierarchical classification and multiple classification
object-oriented classes
object-oriented data types
personal information
problem of classifying information
problems with type inheritance
type hierarchy


A taxonomy is a hierarchical classification for some domain. Each class defines the genus for its sub-classes. Sub-classes are defined by differentia from the genus.

Taxonomies arise naturally in language, although they tend to be fairly flat with a large generic level. Filing systems follow some kind of taxonomy. Many fields have a formal taxonomy, the best known being biology.

A taxonomy is somewhat arbitrary, especially in distinguishing related classes. This problem is more or less solved by depending on experts to make the necessary choices. (cbb 4/94)

An exclusive classification requires a global, top-down view of the world. But classification depends on the actual objects which requires a bottom-up view. It is probably more natural to allow multiple classes and cross-references. This allows localized classification with eventual rationalization into a global classification. (cbb 1/90)

Subtopic: genus and differentia up

Quote: a class is defined by a genus and those attributes that distinguish members from other members of the genus [»maclBJ12_1983]
Quote: Aristotle defined categories for the primitive concepts (e.g., relation, time); build concepts from general type (genus) and differentia [»sowaJF_1984]

Subtopic: classification up

Quote: classification view of systems depends on a global perspective; communication view is localized and observable, like Plato's cave dwellers [»wegnP10_1986]
Quote: in classification want to identify membership in a class (top-down hierarchy) and understand relations between classes (bottom-up) [»wegnP10_1986]
Quote: object-oriented programming: decide on classes; provide a full set of operations for each class; sub-classes will inherit these operations [»stroB5_1989]
Quote: during application design need a bottom-up construction of classification because the domain is uncharted [»wegnP10_1986]

Subtopic: hierarchical classification up

Quote: in folk biology, hierarchically classify by life form, generic, specific and varietal; generic largest and defines the fundamental units [»berlB2_1973]
Quote: lexicographical hierarchies of names have a basic level where people can list many features; above it, descriptions are brief [»millGA7_1990]
Quote: in almost all folk biologies, life form and generic taxa named by primary lexemes; specific and varietal taxa named by secondary lexemes [»berlB2_1973]
Quote: in most folk biology classifications, the unique beginner is not named, e.g., "plant"

Subtopic: terminology model up

Quote: assign a category type for each query type; assign medical semantic types to category types; e.g., 'headache' to 'problems'; use common parent for sub-groups [»pratW7_1999]

Subtopic: filing information up

Quote: basic-level categories such as 'chair' or 'water' are human-sized; they depend on how people interact with objects [»lakoG_1987]
Quote: Agenda items tend to be filed in only a few places; why filing cabinets work acceptably [»kaplSJ7_1990]
Quote: if an Agenda category is exclusive, only one sub-category per item; mutual exclusion

Subtopic: problems with taxonomy up

Quote: phenomena can be taxonomized in an infinite number of ways at different hierarchical levels; interesting generalizations for each one
Quote: categorizing information is difficult; systems can help by automatic classification

Related Topics up

Group: data type   (34 topics, 730 quotes)
Group: type inheritance   (13 topics, 394 quotes)

Topic: abstraction by common attributes (19 items)
Topic: classification (65 items)
Topic: decomposition of a system into levels (49 items)
Topic: definition by example (26 items)
Topic: hierarchical structures (46 items)
Topic: non-hierarchical classification and multiple classification (16 items)
Topic: object-oriented classes (67 items)
Topic: object-oriented data types (29 items)
Topic: personal information (41 items)
Topic: problem of classifying information (42 items)
Topic: problems with type inheritance (20 items)
Topic: type hierarchy
(18 items)

Updated barberCB 2/05
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