Most dissertations that lose marks unnecessarily don’t lose them for lack of effort or weak ideas — they lose them to a handful of avoidable mistakes that repeat year after year. If you’re deep in dissertation season right now, this is worth a quick read before you submit, not after.
1. A research question the dissertation doesn’t actually answer
This is the single most common issue markers report. Somewhere between the proposal and the final draft, the dissertation’s focus drifts — new findings pull the discussion in a different direction, or the conclusion answers a slightly different question than the one posed in the introduction. Before submitting, go back to your original research question and check, sentence by sentence in your conclusion, that you’re actually answering it. If the answer feels indirect, your conclusion needs rewriting, not your research.
2. A literature review that summarises instead of argues
A literature review that goes source by source, describing what each one says, reads as a summary rather than a foundation for your own argument. Markers want to see the gaps, tensions, and debates between sources — and where your own research fits into that conversation. If your literature review could be rearranged into any order without losing meaning, it likely needs a stronger argumentative thread running through it.
3. A methodology that isn’t justified, just described
Describing what you did isn’t the same as justifying why you did it. “I conducted 12 semi-structured interviews” tells a marker your method. “Semi-structured interviews were chosen over surveys because this study aimed to capture nuanced individual experiences that a fixed-response format would have flattened” tells a marker you understood the trade-offs. The second version earns more marks even when the method itself is identical.
4. Findings and discussion that just repeat each other
Your findings chapter should present what you found. Your discussion chapter should interpret it — connect it back to your literature review, explain what it means, and address why it matters. When these two chapters read almost identically, markers read it as a missed opportunity for analysis. If you find yourself repeating the same sentences across both chapters, that’s the signal to add interpretation, not more description.
5. Limitations treated as an afterthought
A rushed, one-paragraph limitations section (“this study had a small sample size and limited time”) signals to markers that you haven’t thought critically about your own work. A stronger limitations section explains specifically how a limitation might have shaped your findings, and what a future study could do differently. This is one of the fastest sections to improve for real marks gained, because most students genuinely have more to say here than they write.
6. Inconsistent referencing that undermines a strong dissertation
This is the most avoidable mistake on this list, and one of the most common. Missing page numbers on direct quotes, sources cited in-text but missing from the reference list, inconsistent date formatting — none of these reflect the quality of your research, but they cost marks anyway, and they’re entirely fixable with a dedicated, systematic check before submission.
7. A conclusion that introduces new material
Conclusions should synthesise what’s already been argued, not introduce new evidence, new sources, or new arguments for the first time. If you find a new idea belongs in your conclusion, it usually means it’s missing from your discussion chapter, and that’s where it needs to move.
The common thread
Almost every mistake on this list isn’t about the quality of your research — it’s about how clearly that research is connected together, chapter to chapter. That’s exactly the kind of issue that’s hard to see in your own writing after weeks of close reading, and exactly what a structural review before submission is designed to catch.