Plagiarism prevention and detection

Plagiarism of projects submitted by students for evaluation in courses at the undergraduate level is a problem that produces increasing concerns in instructors in universities, since detection of plagiarized documents is becoming harder in continuously assessed courses, where the number of projects delivered by students is huge. Plagiarism presents particular features in Computer Science and related degrees, such as: (i) students must learn distinction between plagiarism and software reutilization as a basis of professional honesty, (ii) project-based assessment is widely extended and cannot be fully based on individual interviews with students, (iii) implementation-related skills are assessed by reviewing the source code of projects and (iv) sharing of knowledge has to be promoted among students. 1.2. Alternatives In this paper we describe a study on plagiarism detection in programming projects of 8 courses of a BSc in Computer Science. 865 projects of different size (from 20 to 2000 source code lines) written in C and Modula-2 programming languages were screened using two plagiarism detection software tools that produce originality reports for each project including a global similarity index (SI). The reports were individually analysed in detail by the instructor of each course showing that eve