Computational models are powerful tools--too powerful, according to some. We argue that the idea that models can "do anything" is wrong, and we describe how their failures have been informative. We present new work showing surprising diversity in the effects of feedback on children's task-switching, such that some children perseverate despite this…

This article reviews a particular computational modeling approach to the study of psychological development--that of constructive neural networks. This approach is applied to a variety of developmental domains and issues, including Piagetian tasks, shift learning, language acquisition, number comparison, habituation of visual attention, concept…

An analysis of the quantitative processes underlying conservation of quantity is presented. Models of three quantitative operators--subitizing, counting, and estimation--are derived from adult performance in quantification tasks, and some features of the operators are described. The emergence of conservation is described in terms of the…