Being an experienced teacher, Teacher A used his own established set of problems and required students to write strategies for between one-third and one-fourth of their assigned homework problems. He typically used the approach with more advanced problems (multiple steps, more advanced mathematics, or a combination of multiple principles) and utilized the two-column solution format in an informal way. In contrast, relatively inexperienced Teacher B relied exclusively on researchers'sample materials and copied the strategies word-for-word when writing on the board.
Students were provided with blank worksheet templates for writing strategies and two-column solutions and frequently worked with a partner or small group. In the control section of the class T eacher B used the same problems but formatted them in an equation-focused way. Teacher C used a mix of the researchers' problems and his own, and primarily implemented the approach for later topics (momentum and energy) in conjunction with cooperative learning groups. He had students practice the first steps of strategy writing (principle and justification) for between four and six problems in a worksheet packet and only solve one or two problems completely to present to the rest of the class.