JPlag: finding plagiarisms among a set of programs

Abstract

JPlag is a system that finds pairs of similar programs among a given set of programs. It has successfully been used in practice to detect plagiarisms among student Java exercise submissions. Support for the languages C, C++ and Scheme is also available. This report presents the design of JPlag, in particular the comparison algorithm, and carefully evaluates JPlag's performance on 12 rather different sets of Java programs. The results indicate that JPlag will find all plagiarisms with only very few exceptions. The execution time is less than one minute for submissions of 100 programs of several hundred lines each.