Page 246 - Foundations of Cognitive Psychology : Core Readings

252 Eleanor Rosch

The fifth part is a report of initial attempts to base an analysis of the attributes,
functions, and contexts of objects on a consideration of objects as props in cul-
turally defined events.
It should be noted that the issues in categorization with which we are pri-
marily concerned have to do with explaining the categories found in a culture
and coded by the language of that culture at a particular point in time. When
we speak of the formation of categories, we mean their formation in the culture.
This point is often misunderstood. The principles of categorization proposed
are not as such intended to constitute a theory of the development of categories
in children born into a culture nor to constitute a model of how categories are
processed (how categorizations are made) in the minds of adult speakers of a
language.

The Principles

Two general and basic principles are proposed for the formation of categories:
The first has to do with the function of category systems and asserts that the
task of category systems is to provide maximum information with the least
cognitive effort; the second has to do with the structure of the information so
provided and asserts that the perceived world comes as structured information
rather than as arbitrary or unpredictable attributes. Thus maximum informa-
tion with least cognitive effort is achieved if categories map the perceived
world structure as closely as possible. This condition can be achieved either
by the mapping of categories to given attribute structures or by the definition
or redefinition of attributes to render a given set of categories appropriately
structured. These principles are elaborated in the following.
Cognitive Economy
The first principle contains the almost common-sense notion that, as an or-
ganism, what one wishes to gain from one’s categories is a great deal of infor-
mation about the environment while conserving finite resources as much as
possible. To categorize a stimulus means to consider it, for purposes of that
categorization, not only equivalent to other stimuli in the same category but
also different from stimuli not in that category. On the one hand, it would
appear to the organism’s advantage to have as many properties as possible
predictable from knowing any one property, a principle that would lead to
formation of large numbers of categories with as fine discriminations between
categories as possible. On the other hand, one purpose of categorization is to
reduce the infinite differences among stimuli to behaviorally and cognitively
usable proportions. It is to the organism’s advantage not to differentiate one
stimulus from others when that differentiation is irrelevant to the purposes at
hand.
Perceived World Structure
The second principle of categorization asserts that unlike the sets of stimuli
used in traditional laboratory-concept attainment tasks, the perceived world is
not an unstructured total set of equiprobable co-occurring attributes. Rather,
the material objects of the world are perceived to possess (in Garner’s, 1974,