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How do I apply Filters and Exclusions in Turnitin? | RL-19 | 2022 | Dr. Akash Bhoi thumbnail

How do I apply Filters and Exclusions in Turnitin? | RL-19 | 2022 | Dr. Akash Bhoi

eSupport for Research·
5 min read

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TL;DR

Click the similarity percentage in Turnitin to identify which source group contributes most to the score before making any exclusions.

Briefing

Turnitin similarity scores can swing dramatically when the report settings are off—especially when a student accidentally includes content from the wrong repository or when overlapping submissions aren’t excluded. In one example, a document shows 22% similarity in one place and 88% in another; the higher figure is traced to a configuration mistake (such as forgetting to select “no repository” during class/assignment setup) or to the same document being submitted under another Turnitin account. When that overlap is legitimate to remove—after checking with a supervisor—the fix is to exclude the specific matching sources tied to the inflated portion.

The workflow starts by clicking the similarity percentage (e.g., the 88% figure) to reveal the underlying sources. The report breaks the match into components, such as “82%” coming from the first source group. To remove that inflated overlap, the user selects the matching sources listed under that group and applies “Exclude sources.” After waiting for Turnitin to recalculate, the similarity score drops (in the example, from 88% down to 24%). The instructor stresses that exclusions should be done only with guidance from a supervisor and that excluded sources must be recorded so they can be documented in future submissions and audits. Excluding the wrong material—especially if it includes content that should remain—can create problems later.

Exclusions can be reversed using “Restore,” which brings back previously excluded sources and changes the similarity score again. This is useful for verifying whether a particular match is truly the source of the inflated percentage. The transcript also highlights that similarity reduction isn’t a substitute for academic integrity: simply changing keywords or minor wording may still count as plagiarism. The recommended approach is to rewrite based on understanding, and to cite the original ideas properly—prioritizing primary sources and also citing secondary sources when relevant.

Beyond excluding specific matches, Turnitin offers filter and setting options that target common categories of content. The transcript mentions excluding bibliography/“references” so that reference lists don’t inflate similarity, and excluding quoted material where permitted by institutional policy. It also notes word-based exclusion rules (e.g., excluding a limited number of consecutive words—such as 10 consecutive words—only if the university’s norms allow it). The final similarity view then reflects the adjusted report, including how much of the match comes from different source types (internet, student papers, published works, etc.).

Finally, the transcript covers downloading and managing the report. It advises selecting sources appropriately before downloading, since the downloaded view reflects the current similarity breakdown. The discussion also touches on administrative deletion of submissions: if a document must be removed from the system, the submission ID (and password, if available) can be used to request server-side deletion through administrators. The overall takeaway is that interpreting Turnitin results requires both correct settings and careful, policy-aligned exclusions—paired with proper citation and genuine rewriting.

Cornell Notes

Turnitin similarity percentages can be inflated by configuration issues or by overlapping submissions of the same document in different repositories/accounts. The transcript walks through clicking the similarity percentage to identify which source group drives the match (e.g., an 82% component inside an 88% report), then excluding those sources to force Turnitin to recalculate (dropping, in the example, to 24%). Exclusions should be done only after consulting a supervisor, and excluded items must be recorded for transparency in later submissions. “Restore” can reverse exclusions to confirm whether a particular match is responsible for the score. Even after score reduction, academic integrity still requires rewriting with proper citation of primary and secondary sources.

Why might a document show 22% similarity in one case and 88% in another?

A large jump is often linked to Turnitin settings and repository behavior. The transcript points to forgetting to select “no repository” when creating a class/assignment, which can cause parts of the student’s own work to be stored and matched later. Another cause is submitting the same document under a different Turnitin account or location, creating overlap that Turnitin counts as similarity. In both cases, the inflated percentage comes from identifiable matching sources that can be excluded if the overlap is legitimate to remove.

How does a user exclude the specific source group that drives a high similarity score?

The process starts by clicking the similarity percentage shown on the report (e.g., the 88% figure). The report then lists the contributing source groups, such as a first group accounting for 82%. The user selects the sources within that group and applies “Exclude sources,” then waits for Turnitin to recalculate. In the example, excluding those 15 sources reduced the similarity from 88% to 24%.

What’s the purpose of “Restore,” and what happens to the similarity score?

“Restore” reverses a prior exclusion. The transcript describes restoring one excluded source group and waiting for recalculation; the similarity score then increases again (e.g., from 24% up to 53% after restoring additional sources). This helps verify whether the excluded matches were truly responsible for the inflated score.

Why isn’t rewriting by only changing keywords enough, even after exclusions?

The transcript warns that minor edits—like swapping keywords or changing a few words—can still be flagged as plagiarism because the underlying text similarity remains. The recommended approach is to rewrite after reading and understanding, and to cite where the ideas came from. Proper citation credits the original author and reduces ethical and academic risk even if similarity remains nonzero.

What filter settings can reduce similarity without targeting specific sources?

The transcript mentions filter and setting options such as excluding bibliography/references and excluding quoted material, subject to institutional norms. It also notes word-based exclusions (e.g., excluding up to five consecutive words or ten consecutive words) only if the university’s policy permits it. These settings can lower similarity by removing content categories that are typically not meant to be treated as original text.

How should excluded sources be handled for future submissions?

Excluded sources should be documented. The transcript emphasizes consulting a supervisor before excluding and writing down which sources were excluded so another reviewer can understand the changes later. This prevents accidental removal of content that should remain and supports transparency if the report is checked again.

Review Questions

  1. When a similarity score is unexpectedly high, what steps should be taken to identify the exact source group causing the increase before excluding anything?
  2. How do “Exclude sources” and “Restore” differ in their effect on the similarity percentage, and why would a student use both?
  3. What combination of actions—beyond exclusions—is recommended to address similarity in a way that aligns with academic integrity (rewriting and citation)?

Key Points

  1. 1

    Click the similarity percentage in Turnitin to identify which source group contributes most to the score before making any exclusions.

  2. 2

    Exclude only the matching sources that correspond to legitimate overlap (such as repository/account duplication) and do so after consulting a supervisor.

  3. 3

    Record every excluded source so future checks can verify what was removed and why.

  4. 4

    Use “Restore” to confirm whether a specific exclusion is responsible for score changes by observing recalculated percentages.

  5. 5

    Reduce similarity through genuine rewriting based on understanding, not by minor keyword substitutions that can still trigger plagiarism detection.

  6. 6

    Apply filter settings carefully—such as excluding bibliography/references and quoted material—only within the limits allowed by institutional policy.

  7. 7

    If a submission must be deleted from Turnitin’s system, use the submission ID (and password if available) to request administrative/server-side removal.

Highlights

A high similarity score (e.g., 88%) can be driven by a specific internal component (e.g., an 82% source group), and excluding that group can sharply reduce the overall percentage (down to 24% in the example).
Exclusions are not a free pass: the transcript stresses supervisor consultation and documentation of excluded sources, plus proper citation and real rewriting.
Filter settings like excluding bibliography/references and quoted material can lower similarity, but only within university norms (including limits on consecutive-word exclusions).
“Restore” can bring back excluded matches and increase the similarity score again, making it a verification tool rather than a one-way fix.

Topics

  • Turnitin Similarity Interpretation
  • Excluding Sources
  • Restoring Excluded Matches
  • Filter and Settings
  • Citation and Rewriting

Mentioned