What is an Acceptable Turnitin Score? 

An acceptable Turnitin similarity score depends on the context, but general guidelines are:

• Plagiarism checkers: Less than 5% similarity is generally acceptable.
• Turnitin specifically: Scores in the green (1% – 24%) and yellow (25%-49%) bands indicate properly attributed sources and are usually acceptable. Over 70% similarity often indicates plagiarism requiring investigation.

In the era of digital access to vast reserves of human knowledge, academic integrity policies have become crucial for educational institutions. Turnitin is a widely used plagiarism detection software that compares student work against an expansive database of web pages, academic journals, books, and previously submitted student papers.

It generates a similarity report highlighting passages in the student’s work that match or are similar to existing sources. But what amount of similarity is considered acceptable? Getting clarity on the proper interpretation of Turnitin scores is important for both instructors and students.

What is Similarity?

Similarity in Turnitin refers to the percentage of text in a submitted student paper that matches or is comparable to text that already exists in Turnitin’s database of webpages, academic journals/books, and previously submitted student works.

The similarity column score indicates the amount of overlapping or similar language between the student’s submitted paper and existing texts that Turnitin has in its repository. This includes both direct word-for-word matches as well as similar phrasing.

However, it’s important to note that similarity does not equate directly to plagiarism. Legitimate incorporation of quotes, widely used academic phrases, and properly cited facts/ideas can increase the similarity score without actually violating academic ethics standards. 

What’s the Difference Between a Match and a Source?

A match refers to extended passages or phrases that are copied verbatim from another text without being properly quoted or cited. Matches show areas where students have directly copied word-for-word from existing works.

A source refers to short phrases or more generic academic language that gets flagged as similar by Turnitin but is properly integrated with citations. Sources show areas where students have appropriately incorporated facts, quotes, or concepts from properly attributed outside texts.

The key difference is that a match indicates improperly used texts without attribution, while a source indicates properly incorporated ideas that are correctly cited. So high similarity could come from many properly attributed sources rather than wholly copied matches. This is why qualitative context matters in interpreting Turnitin scores for potential plagiarism issues.

Similarity Score Ranges

Color	Interpretation
Blue	No matching text
Green	One word to 24% matching text
Yellow	25-49% matching text
Orange	50-74% matching text
Red	75-100% matching text

Turnitin categorizes similarity scores into colored ranges to guide visual interpretation:

Blue (No matching text): This means no text from the work matches anything else in Turnitin’s database. A no-match, 0% similarity score does not guarantee an original work without plagiarism, but it does indicate that copied passages were not detected.

Green (One word to 24% matching text): This shows that some small phrases or widely-used language is generating matches, but overall scored similarity is low. Proper quoting and citation generally result in scores in this range.

Yellow (25-49% matching text): This mid-range band indicates a moderate amount of matching or similar text. Scores at the higher end may warrant some scrutiny of improperly used sources without attribution.

Orange (50-74% matching text): This range indicates a majority of the submitted work contains extensive matching or comparable text found in existing sources. Misused sources and plagiarism concerns are likely.

Red (75-100% matching text): Very high similarity detected. A majority of the text closely matches other sources in Turnitin’s database. Clear and pervasive academic ethics violations need investigation.

What Percentage of Plagiarism is Acceptable?

General guidelines for acceptable Turnitin similarity scores:

Plagiarism Checker: Scores of 5% or less similarity indicate properly referenced incorporation of some quotes or commonly used language. This is an acceptable level of accounting for legitimate overlaps.

Turnitin: Scores in the green and yellow bands, from 0% up to 24% (below 25%), or possibly 49% similarity, are generally acceptable levels indicating properly attributed sources. Over 70% similarity is problematic, with higher values indicative of plagiarism requiring further examination.

How Does Turnitin Detect Student Collusion?

In addition to matching text from existing sources, Turnitin also compares student work to that of classmates to check for potential collusion or unauthorized collaboration. Multiple submissions on the same assignment with very high text similarity can indicate students working together too closely without properly individualizing and citing content.

There are certain situations that can inadvertently inflate similarity scores despite not actually involving plagiarism:

• Student Name Matching: Students submitting assignments they previously uploaded to Turnitin can generate false name matching. Using the setting to exclude quotes and small matches helps avoid this.

• Draft Resubmissions: Students submitting multiple draft versions of the same paper to Turnitin can show high matches to their own previous work. However, this similarity of their own work does not violate academic ethics policies.

How to avoid a high similarity score percentage on Turnitin

Here are some tips to avoid getting a high similarity score percentage on Turnitin:

1. Properly paraphrase and summarize source material instead of directly quoting long passages. Use your own words to demonstrate understanding.
2. Enclose any short verbatim quotes from sources in quotation marks and cite them properly. This shows you are attribution the content.
3. Standard background information and discipline-specific academic language will generate some baseline similarity even when properly incorporated. This is normal, don’t try to avoid using relevant terminology.
4. Consistently follow a citation style guide like APA or MLA format to attribute sources rather than presenting outside ideas as your own.
5. Submit early drafts to Turnitin to check similarity scores before the final submission deadline. This allows time to identify any improper sourcing and make edits to reduce high similarity before submitting the final paper.
6. In your own analysis and conclusions, share insights that move beyond restating existing ideas from sources. This differentiates your work.
7. Exclude quotes, bibliographies, and small matches when generating the Turnitin report. This avoids improperly inflating the similarity score percentage.

The key approach is to properly integrate and cite sources while contributing original analysis rather than solely reusing long excerpts from existing works unlabeled as quotes. Following standard citation policies and styles legitimizes incorporating existing material into your submissions.

Difference Between Similarity and Plagiarism

The main differences between similarity and plagiarism are:

Similarity refers to the quantified percentage score Turnitin generates by comparing student work against its database. It is the amount of overlapping or comparable text.

Plagiarism is the qualitative act of presenting someone else’s words or ideas as your own without properly attributing the source. This violates academic integrity policies.

While related, some key differences exist:

• It is possible to have a low similarity score but still have plagiarized parts of a work without proper citations.
• Properly referenced quotes, discipline-specific academic phrases, and background information can yield high similarity scores despite not constituting plagiarism.
• The similarity score does not distinguish between appropriately attributed sources versus copied matches from uncited texts. Qualitative context matters.

So a high similarity percentage alone does not inherently indicate academic misconduct or plagiarism. Instructors have to interpret the Turnitin report in context rather than directly equating quantified similarity with plagiarism judgments. There are situations where similarity differs substantially from determinations of plagiarized content. Review beyond the score is crucial.

Key Takeaways (How to Interpret the Similarity Report)

Here are the key takeaways for properly interpreting Turnitin similarity reports:

1. The similarity score is a useful starting point but does not definitively indicate plagiarism on its own. Qualitative context around source attribution matters hugely when judging violations of academic integrity policies.
2. Distinguish between matches and sources. The matching or highly similar text could arise from proper quoting and citation rather than copied passages without acknowledgment. Identify whether flagged areas are attributed.
3. Acceptable similarity score thresholds depend on context. General guidelines are 0%-5% for plagiarism checkers and 0%-25% green band for Turnitin specifically. However, lower scores can still involve some plagiarism, while higher scores could predominantly reflect properly referenced source usage.
4. Consider allowing students to submit drafts and interpret similarity reports early on. This identifies improperly used sources needing attribution or paraphrasing to reduce similarity percentages prior to final submission.
5. Adjust settings like the bibliography exclusion to avoid improperly inflating scores when you generate a new similarity report. Small matches and student name matches can inappropriately increase percentages.