Tracing vs. Writing Code: Beyond the Learning Hierarchy

Much work has been done on the achievement gap between code tracing and code writing in CS1 students. The generally accepted explanation for this gap is that tracing and writing form separate steps in a learning scaffolding; students must first learn to trace code before they can be expected to write code. The expectation is that once students have mastered these skills, future grades will be driven by their ability to understand the deeper learning concepts, and so the gap between tracing and writing should disappear. In this paper, we detail and evaluate a study on 384 CS2 students to evaluate whether a tracing-writing gap still exists, and assess whether anything can be deduced about students who continue to exhibit such a gap. We find that not only does the gap seem to have closed by CS2, students are equally likely to show a reverse gap in the writing-tracing direction. However, further analysis shows a strong correlation between students who do continue to have a gap (in either direction) and poor overall performance in the course.