A Theoretical Framework for Operationalizing Basic Level Categories in Knowledge Organization Research

Research on categories indicates that superordinate categories lack informativeness because they are represented by only a few attributes while subordinate categories lack cognitive economy because they are represented by too many attributes (e.g., Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976). Basic level categories balance informativeness and cognitive economy: They represent the most attributes common to category members and the fewest attributes shared across categories. Green (2006) has suggested that the universality of basic level categories can be used for building crosswalks between classificatory systems. However, studies of basic level categories in KO systems have assumed that the notion of a basic level category is understood and have failed to operationalize the notion of "basic level category" before applying it in the analysis of user-generated vocabularies. Heidegger‘s (1953/1996) notion of handiness (i.e., zuhandenheit, or being ―at hand‖) can provide a framework for understanding the unstable and relational nature of basic level categories and for operationalizing basic level categories in KO research. A substantial body of research indicates that basic level categories are the first categories formed during perception of the environment, the first learned by children, and those most used in language (e.g., Mervis & Crisafi, 1982; Tversky & Hemenway, 1983). In his seminal article, Roger Brown (1958), who is often identified as the first researcher to have theorized the existence of a basic level of categorization (e.g., Lakoff, 1986; Murphy 2002), described how parents teach their children to name and categorize objects. He argued that the ―name of a thing, the one that tells what it ̳really‘ is, is the name that constitutes the referent as it needs to be constituted for most purposes‖ (p. 17). Brown points out that, while some names given to an object are ―recategorizations‖ that represent ―acts of imagination‖ (p. 17), the names of things as they really are serve as true representations of the referent. Brown's contention that category names of things represent things "as they are" -as the thing "needs to be constituted for most purposes" -foreshadowed Eleanor Rosch‘s theory of basic level categories. Drawing inspiration from Brown‘s (1958) observations and from Wittgenstein‘s (1953/1963) discussions of language use, Rosch and her colleagues (Rosch & Mervis, 1975; Rosch et al., 1976) developed the theory of basic level categories. Rosch (1978) argued that, in the perceived world, information-rich bundles of perceptual and functional attributes form natural discontinuities and that basic cuts in categorization are made at these discontinuities (p. 31). Working from these assumptions, Rosch et al. (1976; Rosch, 1978) defined basic level categories as most inclusive because they convey "the most information, possess the highest cue validity, and are, thus, the most differentiated from one another‖ (Rosch et al., 1976, p. 383). According to Rosch and Mervis (1975): Basic objects (for example, chair, car) are the most inclusive level of abstraction at which categories can mirror the correlational structure . of the environment and the most inclusive level at which there can be many attributes common to all or most members of the categories. (p. 586) Thus, while experimental studies have suggested that superordinate categories lack informativeness because they are represented by only a few attributes and that subordinate categories lack cognitive economy because they are represented by too many attributes (Rosch & Mervis, 1975), basic level categories provide a balance between informativeness and cognitive economy because they represent the most inclusive level of abstraction: the level at which the greatest number of attributes are common to category members (e.g.,