What it looks like
An example from Biology.
Kettlewell’s experiments in the 1950s found that more dark peppered moths survived than pale ones in polluted woods. This proves that birds caused the spread of the dark form.
Kettlewell’s experiments in the 1950s found that more dark peppered moths survived than pale ones in polluted woods. But critics argued that he released moths at far higher densities than occur naturally, which may have made them easier for birds to find. A later, larger experiment by Majerus (Cook et al., 2012) used low densities and let moths choose where to rest, and still found that birds ate more of the less camouflaged form. So the case for bird predation is strong — but it rests on more than Kettlewell’s work.
Why markers write it
A source is only as good as the way it was produced. Markers look for signs that you can tell strong evidence from weak — a small sample, an artificial setting, a claim that goes further than its data. In most UK marking criteria, that judgement is what moves an essay from accurate summary into the 2:1 range.
How to fix it in your next essay
- 1Ask how the evidence was producedWho gathered it, from whom, and how? A small sample, an artificial task or a biased source limits what it can show.
- 2Match the claim to the evidenceSwap “proves” for “suggests” unless the evidence really settles it. Say how far it supports your point, not just that it does.
- 3Test it against other evidenceDoes a later or larger study agree? Where sources clash, say which is more convincing, and why.
Phrases that help
How much it costs
In most UK marking schemes, critical analysis is what the 2:1 descriptors ask for, so an essay without it often stays in the 2:2 range, however accurate and well read it is.
Typical wording — every university words its bands a little differently. Your module’s criteria have the exact version.
Other ways markers say it
- “Needs more critical analysis”
- “Not critical enough”
- “Accepts sources uncritically”
- “Takes evidence at face value”
- “Limited critical engagement”
Often written alongside
Common questions
- What’s the difference between analysis and critical analysis?
- Analysis explains what evidence shows. Critical analysis also asks how far you can trust it — its methods, its limits and how it fits with other evidence.
- Do I have to criticise every source?
- No. Test the evidence your argument leans on most. One sharp point about a key study beats a stock limitation tacked onto every one.
- Does critical mean negative?
- No. Critical means judging, and the judgement can be positive — explaining why a study is convincing counts too.