Turnitin flags non-native English writers as AI at 61%.
The failure that got Turnitin removed from a dozen universities.
Turnitin's AI detector flags non-native English writers as AI-generated at up to 61% — nearly 3× the rate for native speakers. In May 2026 a California family escalated a 76% Turnitin flag into federal court. A New York court reversed a student expulsion over a false Turnitin AI flag. American, Boston U, UC Berkeley, Colorado State, DePaul, Georgetown, Michigan State, NYU, University of Cape Town, and Curtin (as of Jan 1 2026) have quietly disabled Turnitin AI detection.
| Population | False-positive rate | Source |
|---|---|---|
| Native English writers | 5–20% | casrai.org 2026 |
| Non-native (ESL) writers | up to 61% | casrai.org 2026 / Turnitin internal |
| Truth-in-AI on German paraphrase | 0.4% (verified) | RAID.signed.json |
Signed proof of 99.6% AUC on German-language paraphrase attack — the same adversarial condition that breaks every commercial detector on non-English text.
Bring your own ESL corpus. We return an Ed25519‑signed score per document.
curl -X POST https://api.trigeochiral.com/detect \
-H 'Authorization: Bearer $TRIALKEY' \
-d '{"text": "Paste any ESL essay here"}'