Twenty years ago when the author was student teaching, he quickly learned what geometry teachers and researchers (e.g., Senk 1985) have long known: High school geometry students struggle with proof. Throughout his career, he has tried to create instructional materials to make proof more accessible to his students. From field-testing materials with…

Five Canadian high school Chemistry classes in one school, taught by three different teachers, studied the concepts of dynamic chemical equilibria and Le Chatelier's Principle. Some students received traditional teacher-led explanations of the concept first and used an interactive scientific visualisation second, while others worked with the…

A training program designed to teach high school students to be specific in their writing is described in this booklet. The first section of the booklet explains the three stages of the program: (1) daily practice in translating a "telling" sentence into a "showing" paragraph; (2) application of "showing" writing to…

Senior high students who were given concepts simultaneously learned more than those who received concepts successively. A second variable, instructional control strategy, contrasted an adaptive (computer-assisted) control strategy with learner control. Performance was above the criterion level for the adaptive condition, but below it for learner…