How to find and judge evidence for an essay.

What counts as evidence

Evidence is anything a reader could check that supports or challenges a claim. In a short argumentative essay, the most useful kinds are:

• Data: statistics, survey results and measurements, ideally from the organisation that collected them.
• Research: studies and reviews published by universities, research institutes and journals.
• Cases: real examples of a policy, product or change that has already been tried somewhere.
• Primary documents: laws, official reports, company statements and court decisions.
• Expert analysis: the reasoning of people who study the subject, used to explain evidence, not to replace it.

Opinion, including well-known people's opinion, is not evidence on its own. It can show that a view exists, but not that it is right.

Where to look

You don't need paid databases. These free sources cover most questions about the next ten years:

A good search habit: search for your narrowed question plus words like “report”, “data”, “evidence review” or “statistics”, and look for results from organisations rather than blogs.

Trace every number back

Statistics travel. A figure from a careful study gets quoted in a newspaper, rounded in a blog post and repeated on a hundred websites, often without the context that made it true. By the time you find it, it may be out of date, exaggerated or about a different country.

Before you use a number, follow it back as far as you can: from the article you found, to the report it cites, to the original data. Then check three things at the source: what exactly was measured, where, and when. If you can't find where a number came from, don't use it.

Five questions for judging a source

1. Who made it, and why?A government statistics office, a university research team, a campaign group and a company selling a product all have different reasons to publish. That doesn't make any of them wrong, but it tells you what to check.
2. How do they know?Look for the method: how many people were surveyed, what was measured, how the study was done. A source that doesn't explain how it knows something is weaker than one that does.
3. When was it published?For fast-moving topics, such as technology, prices or online behaviour, evidence from five years ago may describe a different world.
4. Does it say what I think it says?Read the relevant part, not just the summary or headline. Studies often find something more limited or more careful than the coverage suggests.
5. Who disagrees?Search for criticism of the source or for studies that found something different. If serious people disagree, say so in your essay.

These questions cover the same ground as checklists you may have met at school, such as the CRAAP test (currency, relevance, authority, accuracy, purpose). One more check matters: relevance. A reliable source that answers a slightly different question won't help your argument.

Read sideways, not just down

Professional fact-checkers rarely judge a website by reading it closely. They open a new tab and search for what others say about the organisation or author behind it. This is called lateral reading, and it takes a minute: search the organisation's name with words like “funding”, “criticism” or “who runs”.

Can I use Wikipedia?

Use it to start, not to cite. Wikipedia is often a good overview and its references can lead you to strong sources. Follow those references, check that they say what the article claims, and cite the original source instead of the Wikipedia page.

Primary and secondary sources

A primary source is the original: the dataset, the study, the law, the speech. A secondary source describes or interprets it: a news article, a textbook, a blog. Secondary sources are useful for finding and understanding evidence, but cite the primary source when you can, because that is where the detail is accurate.

Using evidence in your argument

Evidence doesn't speak for itself. Each time you use a piece of it, do three things in order:

• Claim: say what you are arguing in this paragraph.
• Evidence: give the fact, figure or example, with its source.
• So what: explain why it supports your claim, and how far.

The third step is the one most essays skip, and it is where your reasoning shows. How to build each paragraph shows the same pattern at paragraph level. Two or three pieces of strong, well-explained evidence persuade more than ten facts in a row.

Evidence that cuts against you

You will find evidence that doesn't fit your argument. Don't leave it out. Use it. Showing that you have seen the strongest evidence against your position, and explaining why your conclusion still holds (or how you have adjusted it), makes your essay more convincing, not less. Judges and markers look for evidence used fairly, including evidence that cuts the other way.

Record sources as you go

Keep a running list of every source you might use, with the author or organisation, title, year and link. It takes seconds at the time and saves an hour of searching at the end.

If your teacher or the competition doesn't set a referencing style, any consistent style is fine, as long as a reader can find the source. How to reference sources in an essay shows the patterns for web pages, reports and data. In many essay competitions references don't count towards the word limit, but check the rules for yours.

A note on AI tools and sources

AI tools can help you find leads, but they sometimes invent sources that look real, with plausible titles, authors and links. Check that every source exists and says what you are using it for before it goes in your essay. Many schools and competitions also set rules on AI use, so check them and declare any use. Ten Years From Now's AI-use policy, for example, allows AI for finding sources but not for writing, rewriting or structuring an entry.

Further reading

These guides from university writing centres go further on the same ideas. They are written for university students, but most of the advice applies to a 1,000-word competition essay.

• Evidence, The Writing Center, University of North Carolina at Chapel Hill
• Fallacies, The Writing Center, University of North Carolina at Chapel Hill
• Our World in Data, University of Oxford and Global Change Data Lab

Try it on this year's questions

Ten Years From Now is a free essay competition for students aged 14–18, anywhere in the world. Choose one of three questions and make an evidence-based case in up to 1,000 words, judged against six published criteria. Round 1 closes on 28 February 2027 and Round 2 on 15 June 2027.

Next: How to structure an argumentative essay.

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