Relationship between extensions and intensions in categorization: A match made in heaven?

The present study investigated the relationship between category extension and intension for 11 different semantic categories. It is often tacitly assumed that there is a (strong) extension-intension link. However, a recent study by Hampton and Passanisi (2016) examining the patterns of stable individual differences in concepts across participants called this hypothesis into question. To conceptually replicate their findings, two studies were conducted. We employed a category judgment task to measure category extensions, whereas a property generation (in Study 1) and property judgment task (Study 2) were used to measure intensions. Using their method, that is, correlating extension and intension similarity matrices, we found nonsignificant correlations in both studies, supporting their conclusion that similarity between individuals for extensional judgments does not map onto similarity between individuals for intensional judgments. However, multilevel logistic regression analyses showed that the properties a person generated (Study 1) or endorsed (Study 2) better predicted her own category judgments compared to other people's category judgments. This result provides evidence in favor of a link between extension and intension at the subject level. The conflicting findings, resulting from two different approaches, and their theoretical repercussions are discussed. (PsycINFO Database Record

Feature taxonomy: What type of features do children associate with categories and how do they fare in predicting category judgments?

The present study investigates category intension in school-aged children and adults at two different levels of abstraction (i.e., superordinate and basic level) for two category types (i.e., artefacts and natural kinds). We addressed two critical questions: what kind of features do children and adults generate to define semantic categories and which features predict category membership judgment best at each abstraction level? Overall, participants generated relatively more entity features for natural kinds categories, compared to artefact categories, as well as for basic level categories, compared to superordinate categories. Furthermore, the results showed that older children and adults generated relatively more entity features than younger children. Finally, situation features play the most important role in the prediction of category judgments at both levels of abstraction. Theoretical implications and comparable results from previous studies are described in detail.

The Typicality Ranking Task: A New Method to Derive Typicality Judgments from Children.

An alternative method for deriving typicality judgments, applicable in young children that are not familiar with numerical values yet, is introduced, allowing researchers to study gradedness at younger ages in concept development. Contrary to the long tradition of using rating-based procedures to derive typicality judgments, we propose a method that is based on typicality ranking rather than rating, in which items are gradually sorted according to their typicality, and that requires a minimum of linguistic knowledge. The validity of the method is investigated and the method is compared to the traditional typicality rating measurement in a large empirical study with eight different semantic concepts. The results show that the typicality ranking task can be used to assess children's category knowledge and to evaluate how this knowledge evolves over time. Contrary to earlier held assumptions in studies on typicality in young children, our results also show that preference is not so much a confounding variable to be avoided, but that both variables are often significantly correlated in older children and even in adults.