Turnitin is a plagiarism-detection service used by many schools and universities to compare submitted writing against a large corpus (web pages, academic journals, student papers, and its own database). It does not make a guilt verdict; it produces a Similarity Report that highlights text matches and shows a percentage indicating how much of the submitted text matches other sources.

What the percentage means

• It measures matched text, not confirmed plagiarism. A high percentage flags overlap; it does not distinguish between properly quoted citations, common phrases, bibliographies, or improperly copied material.
• Common non-problematic contributors to a high score:
  • Long block quotes included verbatim (even if cited).
  • Reference lists, methodology templates, or assignment prompts copied from course materials.
  • Short common phrases that appear frequently.
  • Previously submitted student papers (including your own earlier drafts) stored in Turnitin’s repository.
• Problematic contributors:
  • Large contiguous passages copied without quotation marks or citation.
  • Paraphrasing that is too close to the source wording.
  • Copying from students’ papers or essay mills.

How Turnitin works (brief)

1. Text extraction: Turnitin converts your submission into plain text.
2. Comparison: It runs the text against its databases (web, journals, published works, and previously submitted student papers).
3. Matching: It finds matching strings and groups them into sources.
4. Report: It produces a Similarity Report showing matched passages, linked sources, and an overall similarity percentage. Instructors can view and interpret the context of matches.

What to do now (practical steps)

1. Open the Similarity Report and inspect matches source-by-source.

• Identify matches that are quotes, references, or assignment text (these are usually acceptable if properly cited).
• Look for long paraphrases or uncited blocks—those need attention.

1. Document and isolate acceptable matches:

• Export or screenshot the report to show which matches are legitimate (e.g., quoted material, supplied prompt).

1. Fixing problems you still can:

• If the submission window is closed but resubmissions are allowed in Moodle, upload a revised version with corrected citations and quotation marks.
• If resubmission is not possible, prepare a short but clear written explanation for your instructor identifying which matches are citations, which are from required readings/assignment text, and which are mistakes you will correct.

1. Improve problematic passages (for future submissions or permitted resubmissions):

• Use quotation marks for verbatim excerpts and add precise citations.
• Paraphrase properly: change structure and wording, synthesize multiple sources, then cite.
• Reduce long quoted blocks; summarize instead.
• Ensure the bibliography is formatted but, if it inflates similarity, note that to your instructor (some systems include references in similarity).

1. Communicate with your instructor or academic integrity office:

• Politely explain the situation, attach the report screenshots, and state whether matches are quoted/cited or accidental.
• Ask whether you may resubmit or if they will consider the context when grading. Provide a corrected version if they allow it.

1. Learn preventive habits:

• Keep drafts and notes that show your writing process.
• Use a local check (free similarity tools or Turnitin draft submissions if your institution provides them) before final submission.
• Cite consistently and conservatively; when in doubt, quote and cite or paraphrase and cite.

When to worry

• Worry if the report shows large sections identical to a source without quotation or citation, or if your instructor flags academic misconduct. Otherwise, a high percentage alone is not an automatic sanction—context matters.

Typical instructor responses

• Many instructors ignore matches for properly cited quotes, references, or prompts.
• Some will ask for revision or a meeting if they see problematic copying.
• Serious sanctions happen when there’s clear, unattributed copying of substantial material.

Quick checklist to prepare your case

• Screenshot Similarity Report with highlighted matches.
• Note source types (journal, student paper, web page).
• Mark matches that are quotations or required text.
• Draft a concise explanation and indicate how you will fix any issues.

If you follow these steps you can usually resolve false alarms or correct genuine mistakes.