Results of 11 studies of classroom practices used with activity-based elementary science programs were combined quantitatively using a composite category system. One finding reported is that teachers trained in program use spent less time talking and more on activities than untrained teachers using the programs. (Author/JM)

Reports on a study which investigated the order of acquisition of intuitive notions of qualitative speed. Results indicated that an array of prerequisites, equivalent, and independent relationships existed among the tasks administered. Confirmed the evolution of reasoning for notions of qualitative speed found by Piaget. (Author/TW)

Describes a study of the mental processes college students use in thinking about speed. Piagetian-type tasks dealing with speed, time, and distance were used in an individual interview format. Males outperformed females on tasks relating to speed, but not on the other tasks. (TW)

Uses two studies to examine developmental and task effects in estimation problems. Results are discussed in terms of student and task characteristics and the implications of such variables on information processing model of learning. Implications for science teaching, learning problem diagnostics, and science curricula are also discussed. (TW)