Most weak theses share the same handful of problems. After a decade of marking, I can tell you the ten mistakes that come up most often — what they look like, why they cost you marks, and how to fix each.
1. The thesis is too broad
Bad: "Social media affects society."
Why it fails: No paper of any reasonable length can defend this. It's a topic, not a thesis.
Fix: "Instagram's algorithmic feed reshaped the marketing strategies of small fashion brands between 2018 and 2023."
2. The thesis is a fact, not a claim
Bad: "There are many ways to teach reading."
Why it fails: A fact is not arguable. Theses argue.
Fix: "Phonics-based reading instruction outperforms whole-language methods in early literacy outcomes for struggling readers."
3. The thesis has no opposition
If no thoughtful person could disagree, your thesis is too weak. A real thesis is something a smart person could push back on. If yours is "exercise is good for health," your thesis is doing no work.
4. The thesis is two theses
Bad: "Climate policy needs reform AND education systems should incorporate environmental science."
Why it fails: One paper, one argument. The conjunction is fooling you into thinking it's coherent.
Fix: Pick one. Build the whole paper around defending it.
5. The thesis announces what the paper will do
Bad: "This paper will examine three approaches to climate policy."
Why it fails: "Examining" is not an argument. The thesis should state the conclusion of the examination.
Fix: "Of the three dominant approaches to climate policy, carbon-pricing models produce the most measurable emission reductions."
6. The thesis uses vague evaluative language
Words like "better," "important," "significant" without specifying compared to what or by what measure are signals of soft thinking. "Important" is a placeholder you should fill in.
7. The thesis assumes its conclusion
If the thesis already presupposes what you're trying to prove, you're begging the question. "We should ban this dangerous activity" assumes the activity is dangerous. Make the case for the danger first; let the policy follow.
8. The thesis is not falsifiable
"This research will improve our understanding of X" cannot be wrong. A real thesis can be argued against with specific evidence. If you can't imagine the evidence that would refute your thesis, the thesis is not yet specific enough.
9. The thesis is buried
It's in paragraph three of the introduction. It's in a sentence connected to two other ideas. Your reader (and your examiner) should know what your thesis is by the end of the first paragraph at the latest.
10. The thesis doesn't match the body of the paper
This one comes up when students write the thesis first, then drift while writing. By chapter three, they're arguing something different. The fix: rewrite the thesis last, after the paper is done. Make sure it actually describes what you ended up arguing.
The single biggest improvement
If you do nothing else: make your thesis specific enough that someone could disagree with it intelligently. Vague theses are easy to write and impossible to defend. Specific theses are harder to write and substantially easier to argue.
The 60-second test
Read your thesis to a friend who hasn't read your paper. Ask three questions:
- What am I arguing?
- What's the opposing view?
- Could this be wrong?
If your friend can answer all three, your thesis is doing its job. If they can't, you have rewriting to do.
