The referencing mistakes that cost the most marks
Short answer
Referencing mistakes
The four referencing errors that cost the most marks are: paraphrased ideas with no citation, in-text citations that do not match the reference list, mixing Harvard variants within one document, and citing sources you have not read. The first is the most serious — unattributed paraphrase is plagiarism even when the wording is entirely your own.
Unattributed paraphrase
Students often believe that changing the words removes the need to cite. The opposite is true: the idea is what requires attribution, not the phrasing.
If you learned something from a source, cite it — even if you now express it entirely in your own words, and even if it seems obvious to you now that you have read it.
In-text and reference list must reconcile
Every in-text citation needs exactly one matching reference, and every reference must appear at least once in the text. Orphans in either direction are penalised and are trivially easy for a marker to spot.
Check both directions before submitting. Reference managers do not do this reliably, particularly after you have cut a paragraph.
Harvard is not one style
Cite Them Right Harvard, Leeds Harvard, Coventry Harvard and AGPS Harvard differ in punctuation, italicisation and element order. Mixing them inside one document is one of the most common technical failures.
Use the guide your own institution publishes, and use only that one. If a generator's output disagrees with your library's guide, the library guide wins.
Citing what you have not read
If you found a claim in Smith citing Jones, you cannot cite Jones directly unless you have read Jones. The honest form is secondary citation: 'Jones (1998, cited in Smith, 2019)' — and the reference list entry is Smith, because that is what you read.
Overusing secondary citation signals shallow reading. Where the source matters to your argument, find and read it.
Fixing a high similarity score properly
A similarity percentage is not a plagiarism score. Correctly quoted and cited material shows as a match and is entirely legitimate.
Open the report and look at what is matching. Properly cited quotations are fine. Uncited paraphrase must be cited. Over-quotation should be paraphrased and analysed. Matches against your own earlier submissions are self-plagiarism, which most institutions treat seriously.
Fix the causes. Do not rewrite sentences purely to defeat the software — that changes nothing about the underlying integrity problem, and article-spinning is itself detectable.
Frequently asked questions
- What is a good Turnitin similarity score?
- There is no threshold. A well-referenced literature review with legitimate quotations can show 25% and be entirely sound, while a 6% score can contain serious unattributed paraphrase. Read the report, not the number.
- Do I need to cite common knowledge?
- No, but the test is whether it is common knowledge within your discipline and would be uncontested by any reader in the field — not whether you personally already knew it. When genuinely unsure, cite.
- Can I reuse my own previous work?
- Not without permission. Most institutions class submitting the same work twice as self-plagiarism. If you want to build on earlier work, ask your tutor first and cite your previous submission properly.
- How do I cite AI tools?
- Most institutions now require disclosure of any generative AI use, and many prohibit it for assessed writing entirely. APA 7 treats it as a software citation. Check your own institution's policy before using it at all — the rules have changed rapidly and vary widely.
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