Ben Curtis / AP

How to fact-check a politician's claim in 10 steps

From Johannesburg to Lagos, Washington to Buenos Aires, trust in politicians has rarely felt lower. Is the anti-politics mood justified? Not always.

In most countries, politicians, like people in many other professions, tend to offer a mixture of correct and incorrect statements when they speak. That's true in South Africa and in Argentina, whether they are presidents or prime ministers, town mayors or local councilors.

So, if the truth is uncertain and you want to know what is true and what isn't, how do you go about it? How do you fact-check a politician’s claims?

1. Discern whether the statement is a claim of fact.

If a statement you see on TV or online jumps out at you as wrong, ask yourself if it a claim of fact. Opinion and rhetoric have a place in public debate. So too does satire. You cannot fact-check opinion. And complaining about satire or the reasonable use of ‘poetic licence’ just makes you look unable to get a joke, overly literal, or both.

Fact-checkable claims are quite easy to spot. They sometimes feature tangible nouns (employment, healthcare, infrastructure), numbers and comparisons (my administration/country is doing better/worse than yours). They also contain statements about what a politician has achieved, or the state the town/country is now in thanks to them. Fact-checks of promises or claims about the future are not usually fact-checks.

2. Decide whether the claim matters.

Before you spend time checking a claim, ask yourself whether it will really affect you, or society at large, if people believe a suspect claim. If it will, then check it and spread the word. If not, move on to something else.

3. Ask for evidence. If the politician doesn’t respond, try to find evidence that supports their claim.

Whether you are a member of the public seeking information from your mayor or a journalist staking out the president’s office, ask the originator of the claim for evidence. You don’t need to be a journalist to do this. Most politicians have websites and Twitter feeds, so it’s easy to ask them for evidence.

If they don’t respond, seek the evidence yourself, even (or especially) if your gut instinct tells you the claim is wrong.

4. When you find evidence – test it.

If the politician does provide evidence, check it against a few standard tests:

- When was the information collected? Remember, it's a favorite trick to carefully choose start and end-dates for data to make the numbers look good. Zoom out to get a glimpse of the longer trend.

- How was it compiled, and by whom? What do you know about the source of the data? Are they credible? How was the information gathered? If it’s a survey, how many people were asked and by whom?

- Is the data comprehensive? A small, localized study will not necessarily tell you much about the national picture, and vice-versa.

- Has the evidence been tested by others? Scientists rely on so-called “peer-review” to test discoveries. Has this evidence been published and confirmed by other credible sources?

- Does the evidence actually show what the politician says it does? Read the evidence in full. Don’t take at face value the idea it supports the claim.

5. Think about the context.

Keep numbers in proportion and ask yourself what the claim leaves out. UK statistics experts said a key claim made in last year’s “Brexit” referendum was “potentially misleading” because numbers were presented out of context. The politician who says his opponent saw poor economic growth during his term may be misleading readers if he doesn’t admit his opponent inherited a recession when he came into office.

6. Are they claiming credit that is not due?

Another common trick is to claim credit for something that was the result of another politician’s policies. If a politician takes credit for economic growth during their first weeks in office, they could be misleading listeners. In the same way, politicians can mislead by complaining about rising crime numbers, for instance, without noting that the population has also grown.

7. Find reliable sources to test the claim against.

Depending on your country, the hardest part of fact-checking may be finding reliable sources of information to test a claim against. This is why several fact-checking organizations, such as Full Fact in the UK, have built guides to reliable sources. This is Africa Check’s. Depending on the sort of claim you are checking, the best sources may be government papers and official statistics, company records, scientific studies or think-tank reports. There is no simple guide to reliable sources, but here are some basic rules for fact-checkers: Don’t rely on just one source; check their methodology and their finances; be skeptical, not cynical. One rotten apple does not always turn the barrel.

8. Understand why someone might believe it.

If you want to write about the claim, remember a few rules: Don’t nit-pick. If a number is just slightly off, put it in the “mostly correct” category. Nobody respects a nit-picker, and no one is perfect. Don’t say someone is lying unless you have proof they know their claim is false. Do try to understand why someone else might believe a claim. You don’t win many arguments by calling someone stupid. So, think about why people might believe the claim and take that into account.

9. Accept that you’ll have critics.

It is important to accept that you will have critics. Many studies show that people of all political persuasions are often resistant to evidence that runs counter to what they believe is important and no amount of careful argument and linking to evidence will convince them otherwise. Don’t get into an argument. Move on.

10. Correct your mistakes.

Accept that your critics may sometimes have a point. Nobody is immune to mistakes, and that means you too. Correct your mistakes openly and you enhance your credibility. Hide or deny them and you will destroy it.