Turnitin High Similarity from References: How to Exclude the Bibliography

If your Turnitin similarity score is high because of your references, the bibliography filter is either switched off or Turnitin could not recognise where your reference list starts. Reference lists match other papers that cite the same works, so an unfiltered bibliography can add several percentage points to your score. Here is how to tell, and how to fix it.

How to tell your references are the problem

• Scroll to the last pages of your report. If the reference list is full of highlights, it is being counted.
• Look at the filter list on the report. If "Bibliography" is not shown as excluded, it is included in your score.
• Look at the sources. Many small matches to journal articles or other students' papers, each under 1%, often come from reference entries.

Why Turnitin includes references

The filter is off

Your instructor decides whether the bibliography is excluded. Many do exclude it, but not all. Students cannot change filters on a course submission.

Turnitin cannot find your reference list

Turnitin detects the bibliography by its heading. It works best when the list starts with a clear heading such as References, Bibliography, Works Cited or Reference List. Problems happen when:

• The heading is missing, or styled as normal text inside a text box or table.
• The heading is unusual, for example "Sources I used".
• Appendices come after the references, so the end of the document is not the reference list.
• References are inside footnotes rather than a separate list.

How to bring the score down

1. Give your reference list a plain heading: "References" (APA, Harvard) or "Works Cited" (MLA).
2. Make the heading real text, not an image or text box.
3. Ask your instructor whether the bibliography filter can be applied, and whether quotes are excluded.
4. Check in-text citations are formatted consistently, so cited text can be recognised.
5. Re-check the paper before you submit and compare the score with and without references.

In-text citations and quotations

Quoted passages with citations still count unless your instructor excludes quotes. The newer Turnitin report places these in the Cited and Quoted match group, which markers generally do not worry about. Long block quotations are the main reason a well-cited paper still scores high.

A worked example

Take a 3,000-word essay with a 400-word reference list. If 300 words of the reference list match other papers and 150 words of the body match sources, the score is 450 out of 3,400 words, about 13%. Exclude the bibliography and the score becomes 150 out of 3,000 words, 5%. The writing has not changed; only the filter has.

A report with the bibliography excluded

In this sample, bibliography, quoted text and cited text are all excluded. The paper scored 1% similarity.

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Screenshots shown for illustration. Your own reports arrive as full PDFs in your dashboard.

See also: how the similarity score is calculated and acceptable Turnitin scores for a dissertation.

Frequently asked questions

Does Turnitin count references in the similarity score?

Only if the bibliography filter is off or Turnitin cannot recognise where your reference list starts.

How does Turnitin find the reference list?

By its heading. A clear heading such as References, Bibliography or Works Cited works best.

Can students exclude the bibliography?

Not on a course submission. Filters are set by your instructor.