Comparing Student Assignments by Computer

The possibilities offered by electronic methods of communication are increasingly being made use of these days in education. Course material is made available to students in electronic form. The students' assignments can be handed in via e-mail or Internet. Discussions between students or between students and their lecturer can now take place over the network. The Centre for Computers and Law has developed a program for evaluating the work handed in by students if that work has a digital form. Not only can the program assist in assigning a mark to the students' work, it can also check to see whether students have cheated. In this paper, an outline of the program is given as well as a description of the experiments that have been conducted to test the efficiency of the system. The program described in this paper is a result of the work the Centre has previously carried out on word similarity and conceptual retrieval. The program compares every document with every other document and then sorts all the document pairs on the basis of word similarity. Document pairs with the highest scores are examined by the lecturer and compared. Two experiments were carried out in order to test how effective the program was in detecting fraud. In the first experiment, we gradually changed one document by adding parts of a second document. The second experiment involved trying to fool the system by using synonyms. The results of these experiments were very satisfactory. It could, therefore, be concluded that the system was reliable.