What Content Does Turnitin AI Skip? Non-Prose, Code, and More

Turnitin's AI detector does not analyze every part of your document. The FAQ states: "This qualifying text includes only prose sentences, meaning that we only analyze blocks of text that are written in standard grammatical sentences and do not include other types of writing such as lists, bullet points (short non-sentence structures), or other non-sentence structures." The model also "does not reliably detect AI-generated text in the form of non-prose, or code." The FAQ adds: "In addition, we are not pursuing ChatGPT code detection at this time." One Turnitin help article provides a broader list: "The model does not reliably detect AI-generated text in the form of non-prose, such as poetry, scripts, or code, nor does it detect short-form/unconventional writing such as bullet points, tables, or annotated bibliographies." This means your AI score reflects only the prose sentences in your document, not the full content.

The FAQ defines what the model examines:

"This qualifying text includes only prose sentences, meaning that we only analyze blocks of text that are written in standard grammatical sentences and do not include other types of writing such as lists, bullet points (short non-sentence structures), or other non-sentence structures."

The next sentence: "This means that a document containing several different writing types would result in a disparity between the percentage and the highlights."

The percentage you see is not the percentage of your entire submission. It is the percentage of qualifying prose text only. If your document is 50% equations, 20% bullet points, and 30% prose, the AI score reflects only that 30%. How to read a Turnitin AI writing report covers where that gap shows up on the page.

The FAQ is direct about non-prose content:

"The model does not reliably detect AI-generated text in the form of non-prose, or code, nor does it detect short-form/unconventional writing such as bullet points (short non-sentence structures)."

The FAQ also states: "In addition, we are not pursuing ChatGPT code detection at this time."

This means code blocks, regardless of origin, are not analyzed for AI generation. The detector evaluates only the surrounding prose. A rewriting tool has to respect the same boundaries: what happens to citations, tables and equations in an AI humanizer.

One Turnitin help article provides a broader list of content types the model does not reliably detect:

"The model does not reliably detect AI-generated text in the form of non-prose, such as poetry, scripts, or code, nor does it detect short-form/unconventional writing such as bullet points, tables, or annotated bibliographies."

The next sentence: "This means that a document containing several different writing types would result in a disparity between the percentage and the highlights."

This list comes from a single help article, not the FAQ. If your assignment includes poetry, script-style dialogue, or annotated bibliography entries, those sections may not be analyzed at all.

A release note from August 2023 describes updates:

"We are now able to process long-form prose text in tables."

The next sentence: "Resubmit to reprocess existing submissions that contain tables."

The same release note also says: "Bibliographies are now excluded when processing the AI writing report." Again, the next sentence requires resubmission for existing submissions.

This means tables with long-form prose sentences are now analyzed, but raw data and short labels in tables remain non-prose. Bibliographies are excluded entirely from AI detection processing, which is why Turnitin appearing to flag your references almost always turns out to be something else.

The detection model processes qualifying prose by splitting it into overlapping segments:

"When a paper is submitted to Turnitin, sentences from the submission are extracted and segmented into overlapping sections for prediction analysis. Each segment is classified by the AI detection model and given a value between 0 and 1, denoting the probability of the text being likely human or AI-generated."

Only qualifying prose sentences are extracted and segmented. Non-prose content is not included in this process. The document-level percentage is computed from the qualifying prose segments only.

To summarize what we have covered:

• The AI detector only analyzes qualifying prose sentences written in standard grammatical sentences.
• Code, bullet points, lists, and non-sentence structures are not analyzed.
• The FAQ says Turnitin is not pursuing code detection.
• One help article lists poetry, scripts, and annotated bibliographies as not reliably detected.
• Tables with long-form prose are now processed, but raw data and labels are not.
• Bibliographies are excluded from AI detection processing.
• The percentage reflects only qualifying prose, not your entire submission.

If you receive a Turnitin AI report and want to address the flagged passages, import the report and work on them. Eligible passages can be re-run at no charge.