When mathematics as a tool for thought is not congruent with mathematics as a model for a physical phenomenon : Junior high school students' understanding of relationships among electric current, pressure, and resistance

The present study examined the effects of instruction that avoids the cognitive conflict between mathematics as a tool for thought and mathematics as a model for physical phenomena. Students in four classes of public junior high school received two types of instructions concerning electric current. Students under the experimental condition learned the qualitative relationships among electric current, pressure, and resistance first, and then designed experiments for themselves to obtain the quantitative relationships among these three values. On the other hand, students under the control condition ran experiments that examined electric current when they increased electric pressure for a device with a certain amount of resistance, and learned the quantitative relationships among the three values. It was found that students under the experimental condition did better on tests about the calculation based on the relationships among electric current, pressure, and resistance than students under the control condition