Time for Turnitin to get rid of originality percentage scores?

For some time now, I’ve felt that the originality score in Turnitin is at best unhelpful, and at worst quite a dangerous statistic in the hands of people who don’t understand how to interpret it.

It’s a very blunt instrument, and there are plenty of tales of teachers setting an arbitrary cut off point beyond which they will reject work as being plagiarised, and below which they will consider it acceptable. This fails to take into account the difference between one large chunk of unoriginal work that has been copied and pasted verbatim and a collection of short attributed quotations which between them take the work over the arbitrary cut off point. Of course the latter may not be considered good academic practice, but that is an academic skills issue that can be addressed in the grade given and the feedback and feed forward rather than treating it as plagiarism, which it isn’t.

I have a search stream for turnitin on Twitter set up (in Hootsuite) and some of the comments from staff and students alike are eye opening, not to say eye watering.

  • “It makes grading so easy. 56 percent on Turnitin. Big F. Moving on to next paper.”
  • “On our course, we’re only allowed to submit coursework that has a Turnitin score less than 15% so try rewording some stuff.”
  • “No #turnitin.com .. I’m pretty sure I didn’t plagiarize my own name”
  • “Turnitin.com <<<<< I had 27% plagiarism"
  • “Turnitin saying that 3% of my essay was plagiarized”
  • “turnitin.com said that paper was 39% plagarized and i still got a high B? Looks like i’m changing my last name to Shakespeare”

These comments (which I have deliberately not attributed in fairness to the originators) demonstrate both teaching staff who are apparently using arbitrary cut off points rather than considering each originality report in depth and students who have been given access to the originality report apparently without them understanding the difference between originality and plagiarism and the limitations of Turnitin.

In an ideal world, the solution would be that staff and students receive appropriate training and instruction in how to interpret the originality report, but it’s the kind of thing that doesn’t have a natural home in the curriculum – particularly where Turnitin is introduced for continuing students who may not have the formal Study Skills modules that are common in the first year.

In my view, the percentage (and associated colour coding) serves no useful purpose – particularly with the advent of GradeMark and the ability to see text flagged as unoriginal highlighted in the background whilst marking – and tempts people to infer more from the headline percentage than is appropriate. Turnitin would be greatly improved by removing the percentage and colour coding.

I should say for clarity that I have no objection to showing the percentage match for specific sources within the main report view.



Filed under Turnitin

5 responses to “Time for Turnitin to get rid of originality percentage scores?

  1. CRwales

    We have colleges where the lecturer only “have time to read” the reports picked up by an administrator – how could this happen without rough percentages…..it couldn’t, I cynically reply, you would probably have to look at the reports yourself! However we seem to have a policy that plagiarism is only looked at after the initial marking which may then get the mark adjusted – seems a waste of effort to me!

    • That seems to be a remarkable arrangement. If your lecturers were to use GradeMark and switch the hybrid view on they would see the sections of text which match other sources in the background as they mark so it doesn’t need to be an extra effort.

      Here we’re very clear that looking at the originality reports is an academic responsibility, although of course support is available if they require help with interpretation or a second opinion.

    • Wow that’s an amazing arrangement. I can imagine students deliberately putting in a high percentage just to get a looking in to.

  2. Bob Cisneros

    I definitely agree that originality percentages can be quite misleading and may not be related to plagiarism at all. So many things are “automatically flagged” that often the score is quite inflated. I often look at the scores as a reflection of student writing…..a patchwork of direct quotes(perhaps with everything accurately referenced) rather than original thought.. I used a 25% cutoff in my class this spring, not as a plagiarism marker, but as a way to get the students to use their own thoughts more than just cutting and pasting the thoughts of others as direct quotes. Not sure if it would be better to just limit the number of direct quotes.

  3. I work as a Learning Technologist and always hear the “What percentage should I be looking to get?” question from both students and staff. When the users boil it down to such a blunt measure it’s hard not to agree with you on this point. I think that the percentages can be useful, but only when people understand what they mean. Sadly this can’t happen overnight.

    Over a few years of training though (we started using Turnitin about 5 years ago at our place), staff started to get used to the idea of the scores and what they are used for. I guess it takes constant support and reinforcement and training of staff, rather than a blanket ban.

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