What Does the Asterisk (*%) Mean on a Turnitin AI Score?

When Turnitin's AI detector finds AI-generated content below the 20% threshold, the report shows an asterisk (*%) instead of a number. No percentage is displayed, and no highlights are attributed. This is not an error or a glitch. Turnitin explains that "to avoid potential incidence of false positives, no score or highlights are attributed for AI detection scores in the 1% to 19% range."

So if your report displays *% where you expected a number like 5% or 12%, the detector did find some AI-like text. It just chose not to assign a specific percentage or highlight specific passages, because the confidence level in that range is too low to justify a firm score.

The asterisk exists to protect you from false positives. A false positive happens when human-written text gets flagged as AI-generated. Turnitin is aware that in the 1% to 19% range, the risk of false positives is higher. What a 1% false positive rate means shows how many students that rate touches once a university submits at volume. Rather than assigning a specific percentage that could mislead an instructor into thinking you used AI, Turnitin shows the asterisk as a neutral signal.

The key quote from Turnitin's documentation is: "When AI is detected below the 20% threshold in the report, it is now indicated with an asterisk (*%) and no percentage is attributed." The phrase "no percentage is attributed" is important. The detector did detect something, but it is not willing to commit to a number. This is a conservative approach, and it works in your favor if you wrote the text yourself.

When you get a normal percentage score, Turnitin highlights the specific passages it believes are AI-generated. With the asterisk, no highlights appear at all. The reason is the same: the confidence level is too low. "No score or highlights are attributed" means Turnitin is not pointing to any specific section of your document as problematic.

This can feel frustrating if you want to know which parts triggered the detection. But it also means no specific accusation is being made. Without highlights, there is no evidence to rebut, because no evidence is being presented.

The asterisk is not a finding of academic misconduct. It is a signal that the detector found something below the threshold where it is comfortable making a firm claim. Your instructor may or may not choose to follow up on it. But the absence of a percentage and highlights means there is no concrete evidence to challenge.

If you know you wrote the text yourself, the asterisk is consistent with that. Low-level AI-like patterns can appear in human writing, especially in formal or technical prose, which is the whole argument in why AI detectors flag well-written essays. The detector picked up on something, but not enough to commit to a score.

If you did use AI tools for brainstorming or outlining but wrote the final text yourself, the asterisk may reflect that residual similarity. AI-assisted vs AI-generated is where that line actually sits for Turnitin. The score is too low for Turnitin to act on, which is why it stays as an asterisk.

In most cases, the asterisk does not require any action. If your instructor asks about it, you can explain that the asterisk means the score was below 20% and no percentage was assigned. What your instructor is told to do when your AI percentage is high is the guidance they are working from. You can also note that no highlights were attributed, which means no specific passages were flagged.

If you want to be cautious and reduce the asterisk further, review your document for passages that might read as formulaic or generic. Tightening your phrasing and adding your own analysis can help. If you already have a higher score on a different submission and want to address those flagged passages, you can focus your effort there instead.

Eligible passages can be re-run at no charge, so if you do choose to revise, you can refine your text without additional cost.