Investigates Inhelder and Piaget's claim that ages six to nine or ten represent a stage in children's learning of the concepts of all and some. (HM)

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…

Explores the cognitive development of Nepalese students by administering Piagetian-type tasks and comparing geographically and culturally different children. Boys and girls (N=256) of ages 8, 10, and 12 were administered tasks of conservation, classification and seriation, and causality. Implications for curriculum development in Nepal are made.…

Discusses (1) the need for teachers to understand student conceptions; (2) alternative conceptions that students formulate; (3) changing conceptions; (4) representing conceptual knowledge for studying conceptual change; (5) strategies for inducing change; and (6) a taxonomy of conceptual change. (Contains 61 references.) (MDH)