I examined the impact of a self-diagnosis activity on students’ conceptual understanding and
achievements in physics. This activity requires students to self-diagnose their solutions to
problems that they have solved on their own—namely, to identify and explain their errors—and
self-score them—that is, assign scores to their solutions—aided by a rubric demonstrating how to
solve each problem step by step. I also examined a common practice in the physics classroom in which
teachers manage a whole class discussion during which they solve, together with their students,
problems that students had solved on their own. Three 8th-grade classes studying force and motion
with the same teacher participated. Students were first taught the unit in force and motion. Then a
first summative exam was administered. Next, two classes (59 students) were assigned to the
self-diagnosis activity and the other class to the whole class discussion (27 students). To assess
students’ learning with these a…