Why Turnitin Shows 0% but Hides Scores Between 1% and 19%
This is the most misunderstood part of Turnitin's AI reports. Here's exactly how the detection thresholds work.
When Turnitin displays 0% AI, it means the system found no statistically meaningful AI-generated patterns in the text.
In other words, the linguistic patterns throughout the paper do not match the mathematical signature of an LLM. In this case, the detector is confident that the writing style is human-consistent.
When Turnitin detects some AI-like patterns, but the estimated likelihood falls below 20%, the platform does not display a numerical score.
This does not mean the paper is AI-generated.
It means the detected signal is too weak and too unreliable to present
as a concrete percentage.
*) is a deliberate design choice, not a glitch.
Once the AI likelihood reaches 20% or higher, Turnitin displays the percentage clearly.
At this level, the system has greater statistical confidence that AI-generated text is present. In academic work, a threshold is necessary to protect students who write clearly and formally.
A score of 0% means no AI signal. A score showing *% means weak, inconclusive signal — hidden on purpose. Only 20%+ is shown as a number, indicating higher confidence.