Abstract
This paper proposes an approach to identify pitfalls of students in programming exercise by using snapshots of source code. Proposed method calculates distances between a snapshot and submitted source code by student. This method identifies pitfalls based on these distances and then, provides pitfalls to the lecturers. We applied our method into the snapshots which were recorded in the actual programming exercise. As a result, we identified 46 pitfalls from snapshots of 37 students. We confirmed the reasons of these pitfalls contained misunderstanding toward programming language specification, an algorithm to solve the exercise and content of the exercise. Lecturers can provide appropriate feedback to the students by using the proposed method.
