In 1993 Carey and Smith conjectured that the most promising way to boost students' understanding of the nature of science is a "theory-building approach to teaching about inquiry." The research reported here tested this conjecture by comparing results from two Grade 4 classrooms that differed in their emphasis on and technological…

Students (n = 797) from 36 4th-grade classrooms were taught the control of variables strategy for designing experiments. In the instruct condition, classes were taught in an interactive lecture format. In the manipulate condition, students worked in groups to design and run experiments to determine the effects of four variables. In the both…