Five questions to ask any infographic

Infographics are built to be believed quickly. That is their strength, and also why a bad one spreads so easily. Before you trust one, or share it, run through five questions. It takes about a minute.

1. Who made it, and from what?

Look for the source line. A good one names an organization and a dataset or report, with a year. "Source: survey" or no source at all is a reason to slow down. So is a source that turns out to be the company selling the thing the infographic praises. That doesn't make the numbers wrong, but it tells you whose story you're reading.

If you can, follow the source to the original. Numbers tend to change slightly every time they're copied from one graphic to the next.

2. What exactly is being counted?

"Users," "income," "unemployment" and "inflation" each have several definitions. An infographic that compares two countries may be using different ones for each. Check who was counted (adults, households, full-time workers) and when. A statistic from 2017 presented as current is one of the most common problems we see.

3. Does the chart fit the numbers?

A few quick checks:

• Do the bars start at zero? If not, differences look bigger than they are.
• In a pie, do the slices add up to 100 percent?
• If icons or circles are different sizes, is it the area or the height that matches the value?
• Is a money comparison across decades adjusted for inflation?

Any one of these can turn accurate data into a misleading picture.

4. What's the comparison?

A number on its own rarely means much. "3 million people" is a lot for a city and few for a country. Good infographics give you a comparison: last year, another group, a share of the total. If the piece gives you only big raw numbers, ask what they should be compared with.

5. What might be missing?

Every infographic leaves things out, and it has to. The question is whether the omission changes the conclusion. A chart that starts in the year after a big drop can make a recovery look like growth. A ranking of ten countries may skip the eleventh that breaks the pattern.

You won't always be able to answer this one. Asking it still makes you a more careful reader, and if you make infographics yourself, it is the question to ask about your own work before anyone else does.

Our mistakes guide covers the same ground from the designer's side.