Responds to Mandler's critique of authors' view of infant categorization. Maintains that their view of infant categorization is not characterized by a shift from one type of category to another but by gradual changes in the kinds of information infants can use in forming categories. Clarifies position regarding a single categorical process using…

This study examined how novel words foster the formation of object categories for 12- to 13-month olds. Results indicated that by 12 to 13 months, infants have begun to distinguish between novel words presented as count nouns versus adjectives in fluent, infant-directed speech, and that infants' expectations for novel words accord with this…

Evaluated infants' ability to form new object categories based on either visual or naming information at 16 and 20 months using an object manipulation task. Found that infants at both ages showed evidence of using visual information to categorize the objects. Only 20-month-olds used naming information. Found a correlation between vocabulary size…

Adapted Keil's predictability method to examine adults' and preschoolers' conceptions of numbers, focusing on the ontological distinction between numbers and sets of objects. Found that children, like adults, attribute spatial-arrangement properties to collections much more than to numbers, although both are considered to have quantitative…

Examined representation of pictorial exemplars of humans by 3- and 4-month olds. Results demonstrated an asymmetry regarding the exclusivity of categorical representations formed for humans and non-human animals. Categorical representations for humans included exemplar information, whereas categorical representation for non-human animals was based…

Examined whether 5- and 6-year-olds understand that addition and subtraction cancel each other and whether this understanding is based on identity or quantity of addend and subtrahend. Found that children used inversion principle. Six- to eight-year-olds also used inversion and decomposition to solve a + b - (B+1) problems. Concluded that…

Trained 3-, 5-, and 8-year-olds in temporal bisection task, with nonstandard comparison stimuli spaced linearly between short or long standard visual stimuli. Statistical analyses and results from different theoretical models of the data all suggested that temporal sensitivity was higher in the 8-year-olds than in younger groups, even when the…

The present study builds on earlier work by Meyer and Land (2003) which introduced the generative notion of "threshold concepts" within (and across) disciplines, in the sense of transforming the internal view of subject matter or part thereof. In this earlier work such concepts were further linked to forms of knowledge that are "troublesome",…

The development of the concept of matter was explored in children aged 3-13. Eighty four children were asked to classify four sets of objects and matter and to explain their classifications during interviews. Younger children tended to classify using a mixture of extensive properties (properties of objects) and intensive properties (properties of…

This study tested 148 preschoolers between the ages of 48 and 72 months on a Piagetian number conservation task. Children's judgment accuracy, estimation, and response latency were measured. Children were also questioned about the number conservation principle. A four-step developmental sequence was hypothesized: (1) nonconservation; (2) correct…

Two studies of 7-year-olds and college students tested the hypothesis of a developmental difference in the degree to which subjects' memory performance was controlled by categorical properties vs. specific instance properties of test items. (GO)

Investigated the intercorrelations among tasks that appear to require Piagetian formal reasoning to determine whether formal reasoning is used selectively or all-pervasively. Subjects were 60 undergraduate females. (SDH)

Points out the fact that Piaget's objections to tests as ways of identifying cognitive structures and processes have been largely ignored in most of the replication studies conducted by English and American psychologists. (PEB)

Preliminary evidence indicates that children begin to generalize knowledge in a new way at approximately 3 years of age. Forty children between 1.5 and 3.5 years of age were given two tasks of graded complexity. The first and simpler task used four nonoverlapping classes, each composed of four identical objects. Two of the classes were tagged with…