Mastering Data Storytelling: 5 Steps to Creating Persuasive Charts and Graphs
Data storytelling is one of those “buzzwords” that in actuality is not really a buzzword–it’s reflective of a necessary change in the way humans are making sense of the inordinate amount of information out there today.
It is estimated that by 2020, the digital universe will reach 44 zettabytes, or 44 trillion gigabytes, which is 10 times as much information as there was in 2013.
If you can’t fathom how much that is, then imagine the amount of information represented by the memory in a stack of tablets stretching from the Earth to the moon–six and a half times. Now that’s big data!
It’s no wonder then that making sense of otherwise meaningless numbers through storytelling is a must-have skill for the future. We may live in a digital era, but storytelling is still our primary tool for making sense of the world around us.
Sadly, many communicators are scared to death of numbers. They would rather stick to being wordsmiths, using the occasional stat to back up their points. But in the era of open access data, in which even math-averse journalists are becoming adept at handling large volumes of data, you can only get by with this mindset for so long.
If you’re determined to venture into this brave, new world of data viz, let’s start with some of the basics of telling stories with data and common missteps you should avoid.
The first step to creating effective and persuasive data visualizations is to understand how human perception works.
Contrary to what you may have learned in high school, the process of perceiving an object is much more complex than the conceptual model of a digital video camera, in which our eyes act as a lens, our optic nerves as cables and our brains as processors and hard drives.
Alberto Cairo, in his book The Functional Art, delves deeper into the mechanics of human perception and explains how illusion plays an important role in the way we see the world.
For example, as you’re looking at the screen in front of you, it seems like you can see everything within an 180-degree angle, but in actuality, you can only see with full accuracy those things that lie in a very narrow 2-degree field straight ahead of you.
How is it then that we don’t see a blurry mass of things?
Thanks to rapid eye movements called saccades, our eyes quickly dart around scenes to create composite images from the aggregate information, thus creating the very believable illusion that our eyes act like a 180-degree lens.
What we think we see looks something like the image on the left below, but what our eyes are actually doing is sending “small snapshots” of different points, like the ones on the right.
What does this have to do with information design? It’s useful to know that our eyes don’t fixate on random points in a scene or image but rather prioritize. They first detect basic features and focus on things that stand out such as moving objects, bright-colored patches and uncommon shapes.
These basic features are also called preattentive features: Before we’re even consciously aware of them, our brain is already processing these properties.
For example, when our eyes look at a scene, such as the one above, the first thing our brains detect is the difference between the background and foreground. They can detect where the passageway starts and ends, where the trees begin and end, etc. The higher the contrast between the elements, the easier it is for the brain to discern the difference.
Because our brains are designed in this way, we can quickly make out the bear in the first two images below but not the last:
Since the brain is much better at discerning differences in color rather than shape, the best data visualizations deliberately use shade differences to draw attention to certain key pieces of information.
To save time, the brain has also evolved to group similar objects together and quickly identify objects that are different.
Take a look at these images below.
