Common logic errors made by novice programmers

Errors in the logic of a program (sometimes referred to as semantic errors) can be very frustrating for novice programmers to locate and resolve. Developing a better understanding of the kinds of logic error that are most common and problematic for students, and finding strategies for targeting them, may help to inform teaching practice and reduce student frustration.

In this paper we analyse 15,000 code fragments, created by novice programming students, that contain logic errors, and we classify the errors into algorithmic errors, misinterpretations of the problem, and fundamental misconceptions. We find that misconceptions are the most frequent source of logic errors, and lead to the most difficult errors for students to resolve. We list the most common errors of this type as a starting point for designing specific teaching interventions to address them.