A similarity score is calculated by digitally scanning a submission against a database of journals, papers, and publications to detect text that is similar (potential plagiarism). It is important to encourage students not to focus too much on a high similarity score, but rather to focus on checking their work against what the similarity report highlights to them. The same logic should be applied when marking work.
Once a student has submitted an assignment using Turnitin, a similarity report is generated. In most cases, this is shortly after submission, unless you have set it to only be generated on the due date. If a student has submitted 3 times within 24 hours, then subsequent simiarity reports take 24 hours to generate, or the due date/time, if that comes first.
This can be viewed by staff and, usually, by students.
The Academic Misconduct policy notes that: "It is strongly recommended that students are provided with opportunities to test their draft assignments for plagiarism matches with the software used by the University so that they can gain an understanding of acceptable and unacceptable academic practice in a formative way." (Section 3.1.4 - Academic Misconduct by students)
The similarity score represents the percentage of a student’s writing that is like something found on the internet, in the Turnitin databases, or in someone else’s paper. Similarity does not mean that this work is plagiarized. Consider a student’s use of quotations, citations, and bibliographic material when reviewing this number.
Step 1: Go into your assignment and click on the paper title or similarity score for the paper you want to check.
Step 2: On the right-hand side of the Feedback Studio, you’ll see a bar with red icons in it. You can use this to review any flags, see the score, and make adjustments to the filter or exclusion list.
We’ll go through each of the icons in this bar in order:
Flags – this will highlight any activity that Turnitin has determined to be abnormal. It may not be a cause for concern, but you should always read these to determine if you need to investigate anything further. We’ll go over this in more detail later.
Number – this number is the overall Similarity Score and if you click on this, it will list the sources that match a student’s writing, listed from greatest to least. The colours in this list match the colours highlighted in the student’s writing so you can identify the source and where it is used in the student’s paper.
Bar graph pointing down – this tab shows a breakdown of the sources that match the text in a student’s paper.
Filter – you can use this to exclude certain information like citations, quotes, or bibliographic information from a student’s score.
Cancel icon – this will show sources that have been excluded from a student’s similarity report. Sources can be excluded in the All Sources tab.
The Flags Panel can assist you in determining when a student is explicitly trying to trick the Turnitin system. Note that this may highlight both activity that is suspect, and innocuous activity.
In the example given below, clicking the Flag Report gives one integrity insight to view as a priority. By clicking hidden text, you can see how many suspect characters there are (773 in the example). Consider the presence or absence of each of these elements when addressing questionable student work:
In the example given, there has been a white vertical pipe inserted into every space which Turnitin has picked up and highlighted.
However, if there was white text added on top of a dark background in a stylised document, this would not be a cause of concern.
It is always worth looking at these flags to determine any next steps.
For more details on the similarity score, please see the student focussed guide