How can science teachers support students in developing an appropriate declarative knowledge base for solving problems? This article focuses on the question whether the development of students' memory of scientific propositions is better served by writing propositions down on paper or by making drawings of propositions either by silent or…

Describes an audiovisual teaching unit on the chemical laboratory technique of recrystallization which was developed along problem-solving lines and based on observation of student laboratory behavior. Discussion includes usual procedures for developing such units, how this unit solves problems typically associated with teaching, and its general…

This paper examines ways in which coherent reasoning about key concepts such as variability, sampling, data, and distribution can be developed as part of statistics education. Instructional activities that could support such reasoning were developed through design research conducted with students in grades 7 and 8. Results are reported from a…