Evaluate Arguments and Evidence Critically

The key idea

Choose your judgement by checking an argument's relevance, reliability, sufficiency, and possible bias.

What is it for?

Learn to judge arguments fairly, examine evidence, and express criticism precisely and politely.

What you need to know

Check whether the evidence directly supports the main claim.
Consider whether the source is reliable and the sample is sufficient.
Look for bias, hidden assumptions, and unsupported generalisations.
Separate a link between two events from proof that one caused the other.
Explain both the strengths and weaknesses before giving your final judgement.

1. Check the evidence against clear criteria

A confident statement is not necessarily a convincing argument. Check four things before accepting its conclusion. Each criterion helps you find a different weakness.

Relevance: Does the evidence support the exact claim?
Reliability: Can you trust the source and its methods?
Sufficiency: Is there enough evidence to support the conclusion?
Bias: Does the source favour one side or leave out important facts?

A shop claims that its new bags last longer because one customer used one for a year.

The example is relevant, but one customer cannot prove the claim.

A survey of 600 shoppers gives stronger evidence than a survey of six.

A larger sample can help, but its quality also matters.

2. Identify the weakness, not just the conclusion

Look at the steps between the evidence and the conclusion. A weak step can make the whole argument less convincing. Name the problem and explain its effect.

Generalisation: One example is used to describe a whole group.
Correlation: Two things happen together, but one may not cause the other.
Hidden assumption: The argument depends on an idea that remains unproved.
Missing evidence: The writer makes a claim without enough support.

Three customers complained, so every customer dislikes the service.

This generalises from three people to all customers.

Ice cream sales rise when more people visit the beach, so ice cream causes beach visits.

Both may increase because the weather is warmer.

3. Criticise ideas politely and precisely

Focus on the claim, evidence, or reasoning. Do not attack the writer. A precise criticism explains what is missing and why it matters.

Use 'this overlooks' to identify missing information.
Use 'it rests on the assumption that' to expose an unproved idea.
Use 'the sample is too small to' when the data cannot support a broad claim.
Use 'the evidence does not establish that' when proof is incomplete.

The argument overlooks customers who stopped using the service.

This identifies missing evidence without insulting the writer.

The conclusion rests on the assumption that all shoppers have similar needs.

This names an assumption that needs further support.

4. Weigh the evidence before deciding

A strong critique does not reject every opposing idea. It recognises useful evidence and explains its limits. Then it gives a balanced judgement.

Acknowledge a genuine strength before discussing a weakness.
Compare the quality and amount of evidence on both sides.
Use 'more convincing' when one explanation has stronger support.
Use 'on balance' to introduce your final judgement.
Avoid absolute claims when the evidence remains incomplete.

Although the survey suggests a clear preference, its narrow sample limits the conclusion.

The sentence recognises a strength and explains a weakness.

On balance, the second explanation is more convincing because it uses wider data.

The judgement identifies why one argument has stronger support.

5. Build a clear critique paragraph

A critique paragraph moves from the claim to the evidence, then to your judgement. Each sentence should help explain your decision.

Claim: State the argument you are examining.
Evidence: Identify the main support offered.
Evaluation: Explain its strengths and weaknesses.
Judgement: Decide how convincing the argument is.
Support your judgement with a clear reason.

The proposal claims that longer opening hours increase sales. Its figures show a small rise in one shop. However, the report gives no information about other shops or extra costs. The evidence is relevant but insufficient. On balance, the proposal needs wider testing.

The paragraph moves from the claim to evidence, evaluation, and judgement.

How to do it, step by step

Identify the main claim and the conclusion.
Find the evidence offered to support the claim.
Check relevance, reliability, sufficiency, and possible bias.
Explain the strongest weakness and any useful supporting evidence.
Give a balanced judgement and explain your reasons.

Formulas and key language

Use it for	Example	Another example
The evidence is relevant because ...	The evidence is relevant because it measures actual customer spending.	The evidence is relevant because it records weekly travel costs.
The source may be unreliable because ...	The source may be unreliable because the figures are not explained.	The source may be unreliable because the survey method is unclear.
The sample is too small to ...	The sample is too small to represent all local shoppers.	The sample is too small to support a national conclusion.
This overlooks ...	This overlooks families who cannot afford the new service.	This overlooks workers who travel outside normal hours.
The argument rests on the assumption that ...	The argument rests on the assumption that every customer wants faster service.	The argument rests on the assumption that all workers have similar schedules.
The evidence does not establish that ...	The evidence does not establish that longer hours increase total profits.	The evidence does not establish that the new menu attracts more customers.
A more convincing explanation is that ...	A more convincing explanation is that lower prices attract more shoppers.	A more convincing explanation is that warm weather increases outdoor activity.
Although this supports ..., it does not prove ...	Although this supports the proposal, it does not prove that costs will fall.	Although this supports the claim, it does not prove that every customer agrees.
On balance, the argument is ... because ...	On balance, the argument is partly convincing because the figures cover only one month.	On balance, the argument is weak because important costs remain unknown.

UK / US: British English often uses 'analyse' and 'centre'. American English uses 'analyze' and 'center'. Both forms are correct in their own variety.

Level up: Replace basic words (good, very, nice) with stronger ones. See our A2 to C1 upgrades page.

Model text

A Critique of Longer Opening Hours

1. Claim

The shop manager argues that keeping the store open two hours longer will increase weekly profits. The proposal rests on the assumption that extra opening time will attract enough additional customers to cover the higher staffing and energy costs.

The opening identifies the claim and exposes its main assumption.

2. Evidence

The manager supports this view with sales figures from one Friday evening. Sales rose by 15% during the extra hours, which suggests that some customers value later shopping. This evidence is relevant because it records actual purchases rather than customer opinions.

This part recognises useful evidence and explains its relevance.

3. Critical evaluation

Nevertheless, the figures cover only one evening, so the sample is insufficient to establish a lasting trend. The report also omits staffing costs, electricity use, and sales during normal hours. As a result, higher sales cannot automatically be treated as higher profits. The increase may reflect payday shopping rather than longer opening hours. This alternative explanation has not been examined.

This part identifies missing data and questions the claimed cause.

4. Judgement

On balance, the proposal has some merit, but its financial case remains unconvincing. A trial across several weeks would provide more reliable evidence. The manager should compare total profits, not sales alone, before making a permanent decision.

The conclusion weighs the evidence and recommends a practical next step.

Common mistakes

✗ This argument is stupid.

✓ This argument is poorly supported.

Criticise the reasoning, not the person or the idea with insults.

✗ One customer complained, so all customers are unhappy.

✓ One customer complained, but this does not represent all customers.

One example cannot establish what an entire group thinks.

✗ Sales increased with longer hours, so longer hours caused the increase.

✓ Sales increased with longer hours, but other causes remain possible.

Two events happening together does not prove that one caused the other.

✗ The survey proves that every worker wants shorter hours.

✓ The survey suggests that many workers want shorter hours.

Use careful language when the evidence cannot support an absolute claim.

✗ The report has figures, so the argument is reliable.

✓ The report has figures, but their source needs checking.

Numbers alone do not show that evidence is accurate or trustworthy.

✗ On balance the proposal is weak because costs remain unknown

✓ On balance, the proposal is weak because costs remain unknown.

Use a comma after the opening phrase and a full stop at the end.

Plan it, then check it

Plan

Write the main claim in one sentence.
List the evidence and check its source.
Choose the main weakness and explain its effect.
Compare the strengths and weaknesses before deciding.

Check

Does each criticism name a clear problem?
Have I checked the source and the amount of evidence?
Have I avoided confusing a link with a cause?
Have I criticised the argument rather than its writer?
Does my final judgement match the evidence?

Practice

EXERCISE:

Choose the strongest critical sentence

Choose the sentence that evaluates the argument fairly and precisely.

1.A shop uses feedback from four customers to claim everyone likes its new menu.

The second sentence identifies the evidence problem without making another unsupported claim.

2.A report says sales rose after a shop changed its opening hours.

The third sentence separates a connection from proof of cause.

3.A company claims its service is the fastest, using its own survey.

The first sentence identifies a possible source of bias without claiming dishonesty.

4.A family claims a new heater saves money but gives no cost figures.

The third sentence explains the limit without attacking the family.

5.A survey finds that many bus users prefer more frequent services.

The second sentence recognises useful evidence and identifies another factor.

6.A manager says one successful trial guarantees success in every shop.

The first sentence challenges an unsupported generalisation.

Now write

Your task

Write a critique of this made-up argument in 110-150 words. A local shop owner says longer opening hours always increase profits. The owner uses one Friday evening's sales figures. Sales rose by 15% during the extra hours. The owner gives no figures for wages, electricity, or other evenings. The owner also says every customer wants the shop to stay open later. Evaluate the evidence and reasoning. Identify at least two weaknesses. Recognise one useful point, then give your final judgement. Explain what extra information would help. Use polite, precise language. Do not attack the owner.

Target: 110-150 words

Word bank

relevant evidencereliable sourceinsufficient datapossible biassmall samplehidden assumptionunsupported claimgeneralisationcorrelationcause and effectoverlooksmore convincingon balancefinancial benefitfurther testing

Sentence starters

The owner argues that ...
One useful piece of evidence is ...
However, the figures do not establish that ...
The argument overlooks ...
A more convincing explanation may be ...
On balance, the claim is ... because ...

Use only made-up details. Do not include private information about yourself or others.

Instant feedback on your own text is part of Premium.

Check your writing

Have I identified the main claim and its supporting evidence?
Have I checked relevance, reliability, sufficiency, and possible bias?
Have I explained any hidden assumptions or logical weaknesses?
Have I criticised the argument politely rather than attacking its writer?
Does my final judgement match the strength of the evidence?

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