Situations are rare when a submission receives 0%-5% similarity. It sometimes happens when students were supposed to create opinion pieces sharing their personal thoughts or findings or when text manipulation has occurred.

Whenever you enable Turnitin Similarity for the assignment, it will return some percentage of similarity to the content databases being available for your institution’s account. This could be anything from a direct quote to a works cited list.

If the highlights found constitute legal text borrowings, they shouldn’t contribute to the paper similarity score, and this is when “Exclusions” can come in handy.

Types of exclusions supported

Turnitin Similarity recognizes in-text citations, direct quotes, and a bibliography section. You can always choose to automatically omit them from search results either on the admin or assignment level. Additionally, you may want to make exclusions inside an online report on your own, which is easy to do in the “Settings” from the sidebar.

To skip small matches, you may also indicate the number of words to be ignored by the checker in "Settings" – "Small matches". This could be especially helpful for the assignments that need mentioning a lot of common knowledge or terminology, which is something that can’t be replaced by synonyms.

Individual and group exclusions

Excluding an individual source takes only a few simple steps. From the sources sidebar, choose a source view. For the top matches list, select "Sources Overview". To deep dive into the matches and find even minor overlapping, select the "All Sources" view.

Using the checkboxes, you can save a great deal of time and exclude several sources at once or even skip entire content repositories ("Settings" – "Search repositories").

Depending on your license setup, similarity checks can be run against different content repositories. For Turnitin Similarity, those may be “Internet,” “Publications,” “Global,” or “Private” student papers repository.

By excluding entire repositories, you receive fewer matching sources in the report and, as a result, spend less time reviewing the results. However, excluding repositories might result in some academic misconduct going unnoticed, so it must be considered carefully.

Navigating the excluded content sources

The paper similarity score gets immediately recalculated right after exclusions have been made. But not all of them will reduce the similarity percentage, as similar text overlapping could be found across many content sources, not just one.

To remind yourself of what exclusions have already been applied, you can either go back to the assignment settings or the “Settings” tab in the online report. Excluded sources and repositories can be re-included at any point.

Some of the remaining highlights may still need excluding. The reason could be improper formatting the student used to cite the source. Other than that, you’re all set to grade the paper.

And how often do you apply exclusions to the submission? What are those cases?

You’re very welcome to share your insights in the comments section.