Recap
Evidence is sufficient when its quantity and quality provide apt support for the claim. The broader or stronger the claim, the more (and the more varied) evidence it needs. Weak evidence is too little, unrepresentative, irrelevant, out of date, from an unreliable source, or unexplained. Too much repetitive evidence can also weaken a paragraph. If evidence falls short, narrow the claim or add stronger or different evidence.
Key relationships
| Wording of the claim | What it demands |
|---|---|
| “Some…” | A few clear cases |
| “Most…” | A representative sample showing a majority |
| “All / always / never” | Almost impossible to support; narrow it |
| “Causes…” | Evidence of cause, not just of two things occurring together |
| “The worst / best…” | A comparison with alternatives |
Quantity and quality
- Quantity: is there enough for this claim?
- Quality: is each piece relevant, accurate, credible, representative and current?
- Strong quality can offset lower quantity, but no single source can carry a very broad claim.
Ways evidence falls short
- Too little (hasty generalisation).
- Unrepresentative sample or case.
- Irrelevant to the claim.
- Out of date.
- Unreliable or unnamed source.
- Only one type of evidence.
- No explanation.
Worked mini-example
Claim: “Mobile phones should be banned in all schools.” Evidence: a cousin’s grades and one confiscation. Problems: two anecdotes for a claim about all schools. Fix: narrow to “during lessons” and add a study of 12 schools (invented) plus a teachers’ survey and a concession for break time and emergencies.
The Declaration of Independence (1776) says: “To prove this, let Facts be submitted to a candid world,” and then lists many grievances. The claim (a design of absolute despotism) is about a pattern, so a long, specific list supplies the quantity and the checkability the claim needs.
Audience and sufficiency
- A friendly audience needs less evidence.
- A sceptical audience needs more, and more varied, evidence.
- A specialist audience expects rigorous sources.
- A general audience may accept a clear example plus a trusted statistic.
Mistakes to avoid
- Offering one example for a sweeping claim.
- Equating the amount of evidence with its strength.
- Using irrelevant or outdated evidence.
- Exaggerating the claim instead of narrowing it.
- Piling up similar examples without commentary.
- Treating one type of evidence as always enough.
Quick self-check
- When is evidence sufficient? When its quantity and quality provide apt support for the claim.
- What is a hasty generalisation? A broad claim based on too few or unrepresentative cases.
- How can you fix a claim that outruns its evidence? Narrow the claim or add stronger or different evidence.
- Why does the Declaration of Independence list so many grievances? Its claim is about a pattern of intent, which only many related acts can show.
- Why might a writer use several types of evidence for a sceptical audience? Different readers accept different kinds of proof.
For the full explanation and worked examples, return to the study guide.