  Helping students become proficient problem-solvers is one of the primary
goals of physics courses. In part 1 of this article, we summarized the vast
research on problem-solving relevant for physics instruction, and here we
discuss a concrete example of problem solving in the context of waves from
introductory physics. The goal of this research was to investigate how drawing
of diagrams affects students' problem-solving performance. An introductory
class was broken up into three recitations which received different
instructions related to diagrams on their weekly quizzes: one group was
provided a diagram, another was asked to draw one, and the third was the
comparison group which was given no instructions about diagrams. We find that
students who were provided a diagram performed significantly worse than
students in the other two groups. Furthermore, we find that irrespective of the
condition, students who drew diagrams as part of the problem-solving process
performed better overall despite primarily using a mathematical approach to
solving the problem. Lastly, we conducted think-aloud interviews with students
who solved the same problem to further understand their solution approaches as
well as how drawing a diagram is useful even in situations where a primarily
mathematical approach is used.
