The authors examined inductive reasoning among experts in a domain. Three types of tree experts (landscapers, taxonomists, and parks maintenance personnel) completed 3 reasoning tasks. In Experi-ment 1, participants inferred which of 2 novel diseases would affect "more other kinds of trees " and provided justifications for their choices. In Experiment 2, the authors used modified instructions and asked which disease would be more likely to affect "all trees. " In Experiment 3, the conclusion category was eliminated altogether, and participants were asked to generate a list of other affected trees. Among these populations, typicality and diversity effects were weak to nonexistent. Instead, experts ' reasoning was influenced by "local " coverage (extension of the property to members of the same folk family) and causal-ecological factors. The authors concluded that domain knowledge leads to the use of a variety of reasoning strategies not captured by current models of category-based induction. Cognitive psychologists are increasingly interested in concep-tual functions beyond categorization (e.g., Barsalou & Hale, 1992; Markman, Yamauchi, & Makin, 1997; Pazzani, 1991; Ross, 1996, 1997; Wisniewski, 1995). Particularly, they have focused on the use of categories in reasoning and have proposed a number of formal models of category-based reasoning (e.g., Heit, 1998; Mc-

this article should be addressed to Simone Nguyen, Department of Psychology, University of North Carolina, 601 South College Road, Wilmington, NC, 28403-5612. Electronic mail may be sent to nguyens@uncw.edu

Rather than having universal linguistic categories for some sets of common objects, languages develop their own, idiosyncratic naming patterns for them. Accounting for these patterns requires reference not only to the understanding of stimulus properties by individual speakers of a language, but also to the linguistic and cultural histories of the language they speak. To better understand how these two sources of influence work together to produce linguistic categories, we examined the relations among linguistic categories for 60 common containers for speakers of English, Spanish, and Chinese. We discriminated among several possibilities that imply different relative contributions of the two sources of influence. No single type of relation dominated; the contributions of the two influences varied across different parts of this single domain. We suggest an interaction that is constrained by structure in the stimulus space.

A central question in cognitive research concerns how new properties are generalized to categories. This article introduces a model of how generalizations involve a process of causal inference in which people estimate the likely presence of the new property in individual category exemplars and then the prevalence of the property among all category members. Evidence in favor of this causalbased generalization (CBG) view included effects of an existing feature’s base rate (Experiment 1), the direction of the causal relations (Experiments 2 and 4), the number of those relations (Experiment 3), and the distribution of features among category members (Experiments 4 and 5). The results provided no support for an alternative view that generalizations are promoted by the centrality of the to-be-generalized feature. However, there was evidence that a minority of participants based their judgments on simpler associative reasoning processes. Keywords: Causal-based induction; Generalization; Causal reasoning 1.

Abstract not found

One of the main goals of information architecture is to organize an informational domain into a usable taxonomy. This is, however, a difficult task: final users can classify the same domain differently from experts, differences can arise between different groups of users, and the same users can create different taxonomies for different goals (goal derived taxonomies). Even using a participatory design – employing the card sorting technique – the resulting classification would be a sort of compromise, with some categories and items having a good consensus among users, and others being more problematic. The aim of this paper is twofold. The first purpose is to propose some measure of the fitness of a taxonomy as a both whole and as individual items. Three measures will be presented: a) the consensus analysis; b) an index adapted from Tullis and Wood (2004), here called auto-correlation and c) a new measure, called category validity, conceptually similar to the cue validity introduced by Rosch and Mervis (1975). All of these measures can be calculated from the results of the card sorting. The second goal is to present a contextual navigation that could ameliorate the findability of those items whose classification has been proven to be problematic, and to increase the information scent of the whole domain. An example will illustrate the use of the category validity and the implementation of the contextual navigation.

Traditionally, theories of concepts in psychology assume that concepts are a single, uniform kind of mental representation. But no single kind of representation can explain all of the empirical data for which concepts are responsible. I argue that the assumption that concepts are uniformly the same kind of mental structure is responsible for these theories ’ shortcomings, and outline a pluralist theory of concepts that rejects this assumption. On pluralism, concepts should be thought of as being constituted by multiple representational kinds, with the particular kind of concept used on an occasion being determined by the context. I argue that endorsing pluralism does not lead to eliminativism about concepts as an object of scientific interest.

Four experiments provided evidence for a class of ‘dual character concepts. ’ Such concepts are characterized in terms of both (a) concrete features and (b) abstract values. Three experiments found that when an object fulfills only one of these two criteria, it is judged to be a category member in one sense but not in another. A fourth experiment showed that dual character concepts also support a distinct form of normative judgment.

concept kinds