Critical thinking and analysis

You already use critical thinking in everyday life. For example, you might compare different products before buying something, question a claim you see online or change your opinion when new evidence becomes available.

At university, you develop this approach by questioning ideas more systematically, considering evidence and explaining how you reached your conclusions.

Start by asking questions that help you understand what you are examining:

• What? What is being claimed, explained or proposed?

• Who? Who is making the claim, and whose perspectives are represented?

• How? How does something work, or how was a conclusion reached?

• Why? Why might something happen, or why is a particular explanation being offered?

• What if? What other explanations, possibilities or consequences should be considered?

• So what? Why does this matter, and what can reasonably be concluded?

• What next? What further evidence, action or investigation might be needed?

Different questions help you explore different aspects of a topic. You do not have to ask them in a fixed order or use every question for every task.

Look for assumptions

An assumption is something that is taken to be true without necessarily being explained or established.

For example, imagine someone claims that the most popular solution to a problem must be the best solution.

This assumes that popularity is a reliable measure of quality. You could question that assumption by asking what makes a solution effective, who benefits from it and what evidence supports its advantages.

Recognising assumptions does not automatically mean they are wrong. It helps you consider whether they are reasonable and sufficiently supported.

You can explore a similar questioning approach in the University of Leeds' model for critical thinking.

University assessments often ask you to describe, analyse, discuss, evaluate or critically examine a topic.

These activities are connected, but they place different demands on your thinking.

Description: what is it?

Description establishes the relevant facts, characteristics or background. It helps you explain what something is, what happened or what an author says.

For example, you might describe the main features of a theory, summarise research findings or explain the circumstances of a problem.

Description is important because you need to understand what you are examining before you can analyse or evaluate it.

Analysis: how and why?

Analysis involves examining the parts of something and considering how they relate to one another.

You might investigate:

• How different factors contribute to a problem.

• Why an event or outcome occurred.

• How an argument is constructed.

• How evidence supports or challenges an explanation.

• What relationships, patterns or differences are important.

Analysis helps you move beyond stating what happened or what someone said towards explaining how and why it matters.

Evaluation: how convincing or significant is it?

Evaluation involves making a judgement using appropriate evidence and criteria.

You might consider:

• How strong or convincing an argument is.

• Whether a research method is suitable for its purpose.

• How reliable or relevant particular evidence is.

• Which of several explanations is better supported.

• What the limitations or implications of a proposed solution might be.

A good evaluation explains the reasons for the judgement. Simply calling something effective, unreliable or important is not enough.

Developing an argument or conclusion

An academic argument brings together your reasoning and evidence to support a position or conclusion.

Your conclusion should follow from the analysis and evaluation you have undertaken. It may support one interpretation, favour a particular solution or explain why further evidence is needed.

These are useful ways of thinking, not rigid stages. Description, analysis, evaluation and argument often overlap, and the appropriate balance depends on your subject, assessment and the instructions from your tutor.

Imagine you are working on an assessment that asks:

Would introducing free bus travel be an effective way to reduce car use in a city?

You could approach the question at several levels.

1. Describe the proposal

Begin by establishing what is being considered.

The proposal would remove fares for passengers using local bus services, with the aim of encouraging more people to use buses instead of cars.

This identifies the proposal and its purpose. However, it does not explain whether the proposal is likely to work.

2. Analyse how it might work

Next, examine the factors that could influence its effectiveness.

For example:

Removing fares might encourage some people to switch from cars to buses. However, the effect could depend on other factors, including route coverage, journey times, service reliability and why people currently choose to drive.

This moves beyond description by considering relationships between different factors.

It also identifies assumptions that need examination. For instance, the proposal assumes that ticket prices are an important reason people choose not to use buses.

3. Evaluate the evidence and alternatives

To judge the proposal, you would need to investigate how well the available evidence supports it.

You might ask:

• What evidence is available from places that have introduced similar schemes?

• Did free travel reduce car journeys, or mainly increase journeys by people already using public transport?

• How much would the scheme cost, and how would it be funded?

• Would improving routes or service frequency be more effective?

• Who would benefit, and who might still face barriers to using buses?

The answers would help you weigh the proposal's likely benefits, limitations and alternatives.

4. Reach a reasoned judgement

A possible provisional conclusion might be:

Free bus travel could encourage some people to reduce their car use, particularly where fares are an important barrier. However, its effectiveness would also depend on the quality and availability of bus services. A recommendation to introduce the scheme would therefore need evidence about local travel behaviour, likely costs and the effectiveness of alternative measures.

This conclusion does not simply accept or reject the proposal. It identifies what might work, explains relevant limitations and recognises the evidence needed to justify a decision.

The example is hypothetical. In an actual assessment, you would need to investigate and reference relevant evidence rather than rely on these possible explanations alone.

Critical thinking is not limited to evaluating what other people have written. It can help you approach many different tasks at university.

Reading academic material

Identify the author's main argument and examine how it is supported. Consider assumptions, evidence, limitations and alternative interpretations.

See Reading for practical guidance on reading academic texts actively and critically.

Researching and evaluating information

Consider whether information is suitable for your purpose, how the evidence was produced and how much weight it should carry.

Be aware of your own assumptions. You may be more inclined to accept evidence that agrees with what you already believe.

See Evaluating Information for methods and questions to help you assess sources.

Comparing different arguments or findings

When sources disagree, try to understand why.

They may use different definitions, methods, assumptions or types of evidence. Their findings might apply to different circumstances or populations.

Rather than automatically choosing one source, examine what each contributes and whether the differences can be explained.

Interpreting data

Look for patterns, relationships and differences, but consider what the data can reasonably demonstrate.

For example, two factors may be associated without one necessarily causing the other.

Consider how the data were collected, what may be missing and whether alternative explanations are possible.

Solving problems and making decisions

Identify the problem, examine contributing factors, compare possible responses and consider their likely consequences.

A justified solution should take account of relevant evidence, practical constraints and the needs of those affected.

Developing academic arguments

Use analysis and evaluation to explain what the evidence means and how it supports your conclusions.

A critical argument is not simply a collection of quotations or a list of different opinions. It explains the relationships between ideas, weighs the evidence and makes clear why a particular conclusion is justified.

See Writing for further academic writing guidance.

Before completing an assessment or reaching a decision, consider the following questions.

• Understanding: Have I understood the issue, argument or evidence accurately?

• Assumptions: Have I recognised important assumptions, including my own?

• Analysis: Have I examined relevant factors, explanations and relationships rather than simply describing them?

• Evidence: Have I considered whether the available evidence supports the claims being made?

• Alternatives: Have I considered relevant competing explanations, interpretations or solutions?

• Judgement: Can I explain why my conclusion is reasonable and acknowledge important limitations or uncertainties?

You do not need to reach a definite conclusion about every question. Sometimes the most justified outcome is to explain why the evidence is mixed, incomplete or insufficient.

Critical thinking is not always visible simply because you have asked questions or considered alternatives privately.

When your assessment calls for analysis or evaluation, explain your reasoning so that the reader can follow how you reached your conclusions.

For example, instead of writing only that a study is limited, explain which limitation matters, why it affects the findings and how much confidence can reasonably be placed in the conclusion.

Similarly, when comparing different arguments, explain which points are supported by stronger evidence and why.

The particular expectations will depend on your discipline and assessment. Use your assessment brief, marking criteria and feedback, and ask your tutor if you are unsure what critical analysis should look like in your work.