Benefits and drawbacks of source code plagiarism detection in engineering education

Source code plagiarism is wide spread in beginners' programming courses. Especially, if programming is a minor subject, as for instance in engineering degrees. It is very tempting for students during a programming assignment to use a working copy of a fellow student rather than struggling with the time-consuming coding by themselves. But as learning programming requires a significant personal commitment, we confirm the results of other studies, that cheating leads to higher failure rates and lower scores in the examination. Automatic plagiarism detection systems are therefore measures against cheating. We analyzed the students' achievements and opinions during the last 5 years of operating an automated assessment system with plagiarism detection. The paper discusses in detail the benefits of such a system, e.g. the equal treatment of all students compared to manual plagiarism checks, and shows also the disadvantages, e.g. code obfuscation, that students perform in order to circumvent the system.