Examines preschoolers' understanding of non-observable causal mechanism in causes of illness. Three studies were conducted using subjects from university child care centers. Subjects average five years of age. Results indicated that preschoolers recognize that appearances may be deceiving when it comes to judging causes of illness. Discusses…

Examined whether spatial classification is discovered during play and if external products of play lead children to use space to represent similarity. Found through two experiments--a longitudinal study of four children's classification behaviors, and the examination of play behavior with two types of objects--that comparison of different kinds…

Examined how children's and adults' initial conceptions of objects and space influence predictions about the physical world, but lead the naive person to misconstrue a dynamic event. Found that participants proficiently anticipated where an oscillating screen would contact a hidden object, but underestimated the distance until contact.…

Tested children with apparatus that dropped balls through clear or opaque interwoven tubes. Found that older children could solve configurations with greater number of tubes than younger children. Success with clear tubes did not transfer to opaque tubes. Significantly, errors were consistently directed to location directly below ball's last seen…