Why Does Turnitin Show *% Instead of a Percentage?
Table of Contents
- What Does the *% Score Mean in the Turnitin AI Writing Report?
- How Does Turnitin Determine When to Display *% Versus a Numeric Score?
- Can I Preview My Turnitin AI Score Before Submitting My Paper to My Instructor?
- FAQ
- Sources
- Related articles
Direct Answer – Turnitin displays % instead of a numeric score for AI writing detection percentages below 20% to reduce the risk of misinterpretation. According to Turnitin's official documentation, internal testing found a higher incidence of false positives when the AI detection percentage falls between 0 and 19. To prevent educators and students from over-relying on low-confidence scores, the system replaces any sub-20% result with an asterisk (%) to signal that the result is less reliable and should not be interpreted as definitive evidence that no AI was used [1].
What Does the *% Score Mean in the Turnitin AI Writing Report?
When you see % in the Turnitin AI writing report, it means the detection model found that less than 20% of the qualifying text in the submission may have been generated by AI tools, but the exact percentage is intentionally withheld. Turnitin's AI writing indicator displays one of several possible states, and % is the designated display for scores in the 0–19% range [2].
The asterisk serves as a deliberate visual cue. Turnitin states that "in order to reduce the likelihood of misinterpretation, the AI indicator will display an asterisk (*) for percentages between 0 and 20 to call attention to the fact that the score is less reliable" [2]. This design choice reflects Turnitin's commitment to accuracy—low AI detection scores carry higher measurement uncertainty, and displaying them as precise numbers could give a false sense of certainty.
It is important to understand that % does not mean "0% AI" or "no AI detected." The 0% state is a separate indicator used only when the model identifies no qualifying text as likely AI-generated. Scores that fall into the % bucket could be 1%, 12%, or 19%—the system simply does not surface the exact number because confidence at those levels is insufficient for precise reporting [1].
For submissions processed before July 8, 2024, you may still see an exact numeric score below 20% in older reports. This change applies only to new submissions processed after that date [2].
How Does Turnitin Determine When to Display *% Versus a Numeric Score?
Turnitin uses a strict 20% threshold to separate % (asterisk) display from numeric percentage display. Any AI detection score at or above 20% is shown as an exact numerical percentage, while any score below 20% is masked as % [2]. This threshold was established based on Turnitin's extensive validation studies and internal testing of its detection model.
The rationale behind the 20% cut-off centers on false positive rates. AI detection models, including Turnitin's, are statistical classifiers that measure the probability that a segment of text was generated by an AI tool rather than written by a human. At lower detection levels, the model's confidence decreases, and the rate of false positives—incorrectly flagging human-written text as AI-generated—increases [1].
Turnitin's testing found that false positives occur significantly more frequently when the detection score falls below 20%. By masking low scores behind an asterisk, Turnitin aims to prevent educators from making high-stakes academic integrity decisions based on unreliable data [2]. The company emphasizes that the AI writing indicator should never be used as the sole basis for adverse actions against a student; instead, it is meant to be a starting point for discussion and further review.
This approach also aligns with broader best practices in AI detection. Leading AI detection researchers recommend treating low-probability scores as inconclusive rather than definitive, and Turnitin's *% policy operationalizes that recommendation directly in the report interface [3].
Can I Preview My Turnitin AI Score Before Submitting My Paper to My Instructor?
One of the most common questions students have after learning about the *% display is whether they can see their actual AI detection score before submitting an assignment. Unfortunately, Turnitin's official platform does not allow students to self-check their papers outside of an instructor-created assignment. Unless your institution has enabled Turnitin Draft Coach—which works only within Google Docs or Microsoft Word—you cannot preview your similarity or AI writing report through Turnitin's own system [4].
This limitation means most students submit their work without knowing their AI detection score in advance. If the report later shows *%, the student has no way of knowing whether their actual score is 2% or 19%, which can create unnecessary anxiety and uncertainty.
This is where third-party tools like Turnitin0.com become valuable. Turnitin0.com provides students with official-format Turnitin AI detection and similarity reports before they submit to their instructor. You upload your .docx, .pdf, or .txt file and receive two reports within minutes: a similarity/plagiarism report and an AI writing detection report that matches exactly what professors see in institutional Turnitin systems. This allows you to see your true underlying score—even if it would be displayed as *% to your instructor—so you can understand where your paper stands and make informed decisions before final submission.
FAQ
Does *% mean my paper is safe from AI detection?
No. *% simply means the score falls below 20% and Turnitin withholds the exact number due to lower confidence at that range. It does not guarantee that the paper is entirely human-written. The only indicator that means no AI was detected is the explicit "0%" state [1].
Can a *% score still trigger a review by my instructor?
Yes. The *% state is designed to reduce misinterpretation, not to hide potential AI involvement entirely. Instructors can see that the score falls between 0 and 19% and may choose to review highlighted segments in the AI writing report or discuss the submission with you [2].
Why did my older Turnitin report show a specific low number like 3% or 12%?
If your report was generated before July 8, 2024, it may still display an exact numeric score below 20%. The *% update applies only to submissions processed after that date and does not retroactively change older reports [2].
Can I use Turnitin0.com to check if my paper will show *%?
Absolutely. Turnitin0.com generates real Turnitin AI detection reports that show your complete score, including the actual percentage even if it falls below 20%. You get the same report format that instructors see, so you know exactly where your paper stands before submission.
Is the *% rule the same for all languages?
The *% threshold applies to English submissions processed by Turnitin's English AI detector. Spanish and Japanese AI detectors have separate capabilities and may display results differently. Always check your specific language settings [1].
Sources
- Turnitin's AI Writing Detection Capabilities FAQs — https://guides.turnitin.com/hc/en-us/articles/28477544839821-AI-Writing-Detection-FAQs
- Using the AI Writing Report — https://guides.turnitin.com/hc/en-us/articles/22774058814093-Using-the-AI-Writing-Report
- Turnitin Blog: AI Writing Detection and the Asterisk — What Changed in 2024 — https://www.turnitin.com/blog/ai-writing-detection-and-the-asterisk-what-changed-in-2024
- Can Students Check a Paper in Turnitin for Similarity Before Submitting? — https://helpcenter.turnitin.com/hc/en-us/articles/27811948436237-Can-students-check-a-paper-in-Turnitin-for-Similarity-before-submitting-it-to-an-assignment