Memory & Cognition, 2006, in press (original) (raw)

Effects of classification context on categorization in natural categories

2006

Abstract The patterns of classification of borderline instances of eight common taxonomic categories were examined under three different instructional conditions to test two predictions: first, that lack of a specified context contributes to vagueness in categorization, and second, that altering the purpose of classification can lead to greater or lesser dependence on similarity in classification.

Classification in well-defined and ill-defined categories: evidence for common processing strategies

Journal of experimental psychology. General, 1980

Early work in perceptual and conceptual categorization assumed that categories had criterial features and that category membership could be determined by logical rules for the combination of features. More recent theories have assumed that categories have an ill-defined structure and have prosposed probabilistic or global similarity models for the verification of category membership. In the experiments reported here, several models of categorization were compared, using one set of categories having criterial features and another set having an ill-defined structure. Schematic faces were used as exemplars in both cases. Because many models depend on distance in a multidimensional space for their predictions, in Experiment 1 a multidimensional scaling study was performed using the faces of both sets as stimuli, In Experiment 2, subjects learned the category membership of faces for the categories having criterial features. After learning, reaction times for category verification and typ...

The conceptual base view of categorization

Journal of Psycholinguistic Research, 1985

An experiment was designed to show that some categories, called Type C categories, are mediated by an abstract, interpretively derived conceptual base. To this end, each of four groups of subjects ranked 10 sentences (instances) in terms of how well they illustrated the figurative meaning of a proverb (Proverb group), or how well they illustrated the meaning of an excellent interpretation of the proverb (Excellent Interpretation group), or a poor interpretation of the proverb (Poor Interpretation group), or an unspecified, unstated underlying meaning (Control group). The Excellent Interpretation groups' rankings correlated highly with standard ranks established by the Proverb group, but the Poor Interpretation group's and the Control group's ranking were uncorrelated with these two group's rankings. Apparently, the subjects in the Proverb group accomplished their rankings by using a conceptual base or microtheory similar in meaning to the interpretation used by the Excellent Interpretation group. Discussion centered on the question of whether the Classical, Probabilistic, or Exemplar Views of categorization (Smith & Medin, 1981) could account for the results. It was argued that they could not, basically because Type C categories are more dependent upon interpretive processes than the more perceptually based Type P categories to which these views have traditionally been applied.

The development of contextual categories

Cognitive Development, 1987

Two experiments were conducted to investigate the representation of categories of kitchen and bathroom things in 14-and 20-month-old children. These contextual categories are based on spatiotemporal relatedness rather than on the similarity of form or function that underlies the more frequently studied taxonomic categories. In the first experiment, a preferential-looking technique was used that demonstrated sensitivity to a kitchen category but not to a bathroom category. In the second experiment, an object-manipulation task was used that demonstrated sensitivity to both categories. The object-manipulation task was also used to show the presence of a basic-level category of cars and a more global category of animals. The data indicate that a variety of categories are represented at an early age.

The Cognitive Structure of Social Categories*

Cognitive Science, 1985

Support for the prototype theory of categorization was found i n a study of the structure of social categories. Though occupational terms such as DOCTOR are socially defined, they do not have the classical structure their clear definitional origins would predict. Conceptions of social categories are richer and more complex than those of physical object categories and subjects agree upon them. Comparison of various instructions for eliciting attributes of categories showed that whether subjects are asked to define a term, give characteristics, or describe ways they recognize members of categories, the attributes they list contribute to a prototype structure. These data provide evi dence against the view that prototype structure is relevant only to an identification procedure and not to the care of concepts, as has been suggested.

Concepts and Categorization / 1 Concepts and Categories: Memory, Meaning, and Metaphysics

Not only do people categorize in order to understand new entities, they also use the new entities to modify and update their concepts. In other words, categorization supports learning. Encountering a member of a category with a novel property-for example, a flashlight that has a siren for emergenciescan result in that novel property being incorporated into the conceptual representation. In other cases, relations between categories may support inference and learning. For example, finding out that flashlights can contain sirens may lead you to entertain the idea that cell phones and fire extinguishers might also contain sirens. Hierarchical conceptual relations support both inductive and deductive reasoning. If all trees contain xylem and hawthorns are trees, then one can deduce that hawthorns contain xylem. In addition, finding out that white oaks contain phloem provides some support for the inductive inference that other kinds of oaks contain phloem. People also use categories to instantiate goals in planning (Barsalou, 1983). For example, a person planning to do some night fishing might create an ad hoc concept, THINGS TO BRING ON A NIGHT FISHING TRIP, which would include a fishing rod, tackle box, mosquito repellent, and a flashlight. Concepts are also centrally involved in communication. Many of our concepts correspond to lexical entries, such as the English word "flashlight." In order for people to avoid misunderstanding each other, they must have comparable concepts in mind. If A's concept of cell phone corresponds with B's concept of flashlight, it won't go well if A asks B to make a call. An important part of the function of concepts in communication is their ability to combine in order to create an unlimited number of new concepts. Nearly every sentence you encounter is new-one you've never heard or read before-and concepts (along with the sentence's grammar) must support your ability to understand it. Concepts are also responsible for more ad hoc uses of language. For example, from the base concepts of TROUT and FLASHLIGHT, you might create a new concept, TROUT FLASHLIGHT, which in the context of our current discussion would presumably be a flashlight used when trying to catch trout (and not a flashlight with a picture of a trout on it, though this may be the correct interpretation in some other context). A Concepts and Categorization / 4 major research challenge is to understand the principles of conceptual combination and how they relate to