Accepted Turnitin Percentage

Turnitin is a widely used tool for checking text similarity in academic work. When a paper is submitted, Turnitin generates a similarity report that provides a similarity score—a percentage representing how much of the submitted document matches other sources.

These sources can include web pages, previously submitted student papers, and academic sources like journals and periodicals. However, a high similarity score does not automatically mean plagiarism; it’s simply a flag that something needs review.

What Is a Similarity Report?

The similarity report highlights portions of the text that match content from the vast Turnitin database. Instructors and students can see which parts of the document have been flagged and compare them to the source of the match. While Turnitin doesn’t identify plagiarism directly, it provides the tools necessary to detect potential issues with originality.

Key Features of the Similarity Report

• Percentage of Matched Text: The similarity index percentage shows how much of the submitted work matches external sources.
• Matched Text: Specific portions of the document that match sources are highlighted for easy reference.
• Plagiarism vs. Similarity: A high similarity score does not necessarily mean plagiarism has occurred. Properly cited quotations, common phrases, and even properly sourced references can appear in the report, contributing to the overall similarity score.

Understanding Acceptable Similarity Scores

There is no universal answer for what makes an acceptable similarity score. Guidelines vary depending on the institution, instructor, and type of assignment. Generally, here are some common thresholds:

Similarity Score	Evaluation
0-15%	Very good
15-30% Acceptable	Acceptable
30-40% High	High
40%+	Very high (requires review)

Institutions and teachers may have specific guidelines for an acceptable similarity percentage. Some might allow higher percentages for assignments involving research and citations, while others may expect lower percentages for creative writing or original work.

Similarity Score Colors: What Do They Mean?

Turnitin uses a color-coded system to help both students and instructors quickly assess the originality of a document. These colors correspond to different ranges of similarity index percentages, offering a visual aid to indicate how much of the document matches other sources.

Breakdown of Color Codes

Color	Percentage Range	Meaning
Blue	A high percentage of the matched text. This indicates a serious issue with originality.	No matching text. This suggests highly original work.
Green	1-24%	Small percentage of matching text. Generally acceptable, especially for research papers.
Yellow	25-49%	A moderate amount of matching text. Requires review for overuse of sources.
Orange	50-74%	A large amount of matching text. Substantial revisions are needed.
Red	75-100%	High percentage of matched text. This indicates a serious issue with originality.

The blue and green scores are often considered acceptable, especially for longer papers where matching phrases or commonly used academic terminology may appear. However, yellow, orange, and red scores should be carefully reviewed. These high percentages could indicate improper paraphrasing or over-reliance on external sources, even if citations are provided.

Managing Similarity Scores

Maintaining a low similarity score is essential to meeting academic integrity standards. A high similarity score can raise questions, even if all sources are cited properly. Here are strategies for managing and minimizing your similarity score while maintaining originality.

1. Understand Assignment Instructions

One of the most common reasons for high similarity scores is the misinterpretation of assignment instructions. Failing to understand guidelines on citations and the use of external sources can lead to unintentional plagiarism. Always make sure you clearly understand how much external content is allowed and how to cite it properly.

2. Use Properly Sourced Quotes

When you include direct quotations, ensure they are correctly cited. Quotes are often flagged in plagiarism detection tools, which can raise your similarity score. To mitigate this, make sure all quotes are appropriately attributed. Many institutions allow students to request that their instructors exclude quotes from the final similarity report if they are correctly cited. This helps to lower the overall score without compromising the quality of the submission.

3. Exclude Small Matches

Some similarity reports flag short, common phrases or names that may appear in many documents. For instance, in academic writing, technical terms or industry-specific jargon might be flagged. Instructors or students can use filters to exclude small matches that do not contribute significantly to the overall content.

4. Avoid Over-Reliance on Previous Submissions

Resubmitting previously submitted work, also known as self-plagiarism, can result in an inflated similarity score. Even if the content is your own, Turnitin will flag these matches. To avoid this, either rework the content or request that your previous submissions be excluded from the report.

5. Balance Paraphrasing and Quoting

Overusing direct quotes can inflate your similarity score. Instead, aim to paraphrase where possible, and make sure all paraphrased sections are cited. Paraphrasing shows you’ve understood the material and are expressing it in your own words, which helps reduce the amount of matching text while still respecting the original source.

6. Consult Your Institution’s Policies

Each institution has its own standards regarding acceptable similarity scores. Some may have stricter rules, while others may allow for more flexibility, especially in research-heavy disciplines. Make sure you’re aware of your school’s policies on acceptable similarity scores.

Common Match Patterns in Similarity Reports

When reviewing assignments for text similarity, certain common patterns frequently emerge. These patterns provide insight into how the matched text should be evaluated and what actions, if any, need to be taken.

1. Series of Small Matches

Often, small matches consist of common phrases, academic terms, or widely used expressions. These can contribute to a low overall similarity score (e.g., 1-3% per source). Such matches are usually not a cause for concern, especially if they are common in the field of study. Applying a small match filter or excluding bibliography and quotations can help refine the report and reveal more substantial issues.

2. Large Match to a Single Source

A large match to a single source often indicates over-reliance on that source. For example, a 14% match from one online source suggests that a significant portion of the content has been borrowed from that source. While proper citation is essential, the match breakdown can show how the source was used. Large matches, even if correctly referenced, might suggest poor paraphrasing or limited original content.

3. High Percentage Match to Previously Submitted Work

Occasionally, a similarity report will flag a high percentage match to a previously submitted paper, such as a 100% match to a draft. This could indicate self-plagiarism if the paper has been submitted in a previous assignment or by another student. Institutions often have procedures for investigating these matches.

4. Series of Matches to Several Sources

When multiple sources contribute to a high similarity score (e.g., 21%), it is essential to review each match individually. Proper referencing is key, and even small matches need to be examined in longer assignments to ensure citations are correct.

Student Collusion Detection

Turnitin plays a crucial role in identifying instances of student collusion. Collusion occurs when students share or copy work, which can artificially lower their initial similarity score but increase it later for other students who submit the same or similar work.

How Collusion Is Detected

Turnitin detects collusion by comparing student submissions against its institution’s paper repository and global database. When one student submits work that closely matches another student’s, the similarity report will flag the match.

In cases where collusion is suspected, the similarity report will highlight shared or copied sections of text, allowing instructors to investigate. Even if the submissions were made at different times, Turnitin compares all submissions within the course and flags any overlapping content.

Similarity Score Interpretation

Interpreting similarity scores requires an understanding that the similarity index percentage does not equate to plagiarism. Instead, it reflects how much of the document matches other sources.

• 0% (Blue Score): No matching text. Could indicate either originality or a lack of citations.
• 1-24% (Green Score): Typical for assignments that use external sources.
• 25-49% (Yellow Score): A higher percentage, suggesting over-reliance on external material.
• 50-74% (Orange Score): Substantial matches, indicating the need for revision.
• 75-100% (Red Score): Very high match, likely requires significant changes to avoid plagiarism concerns.

Key Takeaways for Managing Similarity Scores

To ensure academic success and maintain originality in your work, it’s essential to:

• Aim for a low similarity score: Generally, a score below 25% is acceptable, but always check your institution’s guidelines.
• Cite sources correctly: Use appropriate citation styles (APA, MLA, Chicago) to avoid accidental plagiarism.
• Paraphrase wisely: Rewriting information in your own words demonstrates comprehension.
• Use quotes sparingly: Where possible, prioritize paraphrasing over direct quotes to reduce the similarity score.
• Review the similarity report carefully: Ensure that all flagged matches are either properly cited or rewritten.

By following these strategies, students can ensure their work meets the highest academic standards, while also avoiding unnecessary high similarity scores.