Plagiarism detection software: How effective is it?

The first thing to note about plagiarism detection software is that much of it is ephemeral. The available software tends to come and go: new software and websites surface and then disappear. It is difficult to predict how many stable products will emerge.

On the whole, plagiarism detection software can make a useful contribution to minimising plagiarism. The visible use of such software is a strong deterrent to students who are considering plagiarising material. It should be recognised, however, that the software provides no magical answers. Some is expensive; most is time-consuming. No software seems to discriminate between quotations which are properly cited and those which are unacknowledged: what the software detects and notifies is duplication. So reports issued by plagiarism software alert the user to what may appear to be plagiarized material that is in fact appropriately referenced. Manual checking and human judgement are still needed.

Some plagiarism detection schemes require students to submit their work electronically directly to the software company. The company then sends a report on submitted student work to the university. It is important to note that assignment formatting may be lost during the detection process. As a consequence, students must also submit either an electronic copy or hard copy of their work to the university as well - raising the question of how it can be ensured the two versions are identical. If students submit electronic copy, lecturers have to print out the assignment - time-consuming operations in cases where lecturers are assessing large numbers of students.

Some software programs concentrate on comparing the material submitted within a defined group of students; others compare the material submitted with either an in-house data base (compiled cumulatively by the software company), or the web, or both. A number of software plagiarism detection companies offer as part of their service the archiving of student essays, which in turn gives lecturers a specialized in-house data base and, in some cases, the possibility of a secure web environment which can be accessed by students for purposes related to group assessment and peer review.

It is worth remembering, of course, that 'traditional' plagiarism - text copied from books rather than downloaded from the Web - may well persist, but cannot be electronically detected.