Using a chart or graph can be a simple and eye-catching way to display information that might otherwise need paragraphs (or pages!) of text to explain.
When done well, your audience should be able to scan and interpret your graphics quickly and easily. When done not-so-well, simple graphics can confuse a reader. Here are some things to avoid doing when visually displaying information.
3D and other special effects
Using 3D and blow-apart effects can make your data hard to interpret. Think about a 3D bar chart for a minute. The 3D effect is created by angling the bar upward. What part of the bar is your reader supposed to be looking at? The front (the lowest part) or the back (the highest)?
If you’re not there to explain the data, don’t be surprised if your readers can’t figure it out on their own.
Blow-apart effects, which we often see with pie charts, create similar issues. The parts of the pie are harder to compare when they’re blown apart, which can lead to misinterpretation of your data (source). Remember, your readers should be able to interpret a well-designed graphic at a glance. Don’t make them work for it.
Your readers should be able to interpret a well-designed graphic at a glance. Don’t make them work for it.
Another way to make your readers work is to challenge their assumptions. And most readers assume that most charts start at zero. Starting a scale with a number other than zero can distort your information, leaving the impression that your data has been skewed.
Trying to present too much information on a line graph reduces your readers’ understanding of what you’re trying to say, because it makes it difficult to find the data points on your graph. Similarly, too many bars in a bar chart can make it hard to distinguish between groups of data. You’ve seen these charts, where all the information just blends together.
If you have too much information to present, consider creating a series of charts by grouping different sets of data in a logical way. If that doesn’t work, it might be best to skip the chart in this case and tell your story with text.
Too many/non-contrasting colours
Eye-catching graphics use colour, but using too many colours can leave your chart looking messy. It can also confuse readers as they start to lose track of which colour was supposed to represent which piece of information.
Six is the maximum number of colours you should use, but most sources will tell you a three-colour palette is ideal. And if there’s any chance your chart will be printed out or viewed in black and white, choose a palette with plenty of contrast.
Skipping the text
A well-designed graphic is a great way to present information for visual learners. You know, those people whose eyes glaze over when they see paragraphs of text followed by more paragraphs of text. But don’t underestimate how important it is to reach all types of learners. There are plenty of people who will struggle to interpret a line chart no matter how simple it seems or how well it’s designed.
To make the biggest impact and reach the widest audience, use a mix of graphics and well written text. Your readers will thank you.