Turnitin overview (content courtesy of the University of Reading 'Citing References' libguide).
Turnitin is a software program that compares a submitted text to other texts in its database. The database includes published books, journal articles, webpages and other submitted assignments. It checks the originality of the submitted text against these texts and produces a report that shows the percentage of writing that is original, and the source of non-original text.
Although Turnitin has been described as a plagiarism detector, it is actually better described as an originality checker. So a piece of work submitted to Turnitin may have a high percentage of writing that is not original, but this may include a lot of common phrases or acknowledged quotes.
At present, some but not all students at ITT have access to Turnitin before they make their final submission to help them to check their work and correct any errors. If you have this opportunity, here is a guide to interpreting the reports:
1. Check your overall similarity index – the percentage at top right of the report:
Average similarity index – up to about 50% of matches
It is quite normal for an essay to have up to 50% of matches to other items; or even more. This does not mean you are guilty of plagiarism. Remember, Turnitin counts anything in your work which matches another source as unoriginal: so, e.g., if you have used a quotation – in quote marks and correctly attributed – this will be counted as unoriginal material. By counting innocent material in this way, you can build up a significant “similarity index” without being guilty of plagiarism.
High similarity index – coloured amber or red
For reasons given above – regarding an average reading – a high score does not necessarily mean you are guilty of plagiarism: provided you have put all quotations in quote marks, or presented them as indented quotations, and correctly attributed them. But a high score does at least suggest that you have used a lot of quotations; this will make your work seem very derivative. You are unlikely to get you a good mark if your work is a collection of quotations without much of your own input.
Low similarity index – coloured yellow or green
This is a good sign: but does not necessarily mean your work is free of plagiarism. See below.
2. Look at the highest matches – listed 1, 2, 3, etc. on the right of the screen:
A number of small matches is perfectly normal – indeed inevitable – and should not in itself be a cause for concern.
Matches to other students
You might be alarmed to see that Turnitin says content of your coursework matches work by other students. Again, this is not necessarily a cause for concern; this happens if other students have used the same quotations as you. Provided you have used quote marks, or indentation, and correctly attributed the quotation(s) this is not a problem.
Any substantial match, e.g. approaching 10% or more
A substantial match might be a cause for concern. But, it can be entirely innocent: it may be a long quotation, or series of quotations, where you have used quote marks, or used indentation, and correctly attributed the quotation(s). But if the matching material – which you can see by scrolling through the text of your coursework, numbered and colour-coded to match, on the left of the screen – is not in quote marks, or indented, and fully attributed, this will be a cause for concern.
Adapted from School of Law (2012), LLB Programme Handbook 2012-13, University of Reading.