  Drawing appropriate diagrams is a useful problem solving heuristic that can
transform a given problem into a representation that is easier to exploit for
solving it. A major focus while helping introductory physics students learn
problem solving is to help them appreciate that drawing diagrams facilitates
problem solution. We conducted an investigation in which 111 students in an
algebra-based introductory physics course were subjected to two different
interventions during recitation quizzes throughout the semester. They were
either (1) asked to solve problems in which the diagrams were drawn for them or
(2) explicitly told to draw a diagram. A comparison group was not given any
instruction regarding diagrams. We developed a rubric to score the
problem-solving performance of students in different intervention groups. Here,
we present some surprising results for problems which involve considerations of
initial and final conditions.
