Originally published at the IBM Center for Applied Insights blog.

Susanne Hupfer, IBM Center for Applied Insights, April 16, 2014

 

Information graphics — visual representations of information, data, knowledge, or concepts – have been around for millennia, and humans have long mapped data in order to organize what they see, filter out extraneous details, reveal patterns, suggest further exploration, and ultimately better understand the world around them.

Why should we be interested in visualization? Because the human visual system is a pattern seeker of enormous power and subtlety. The eye and the visual cortex of the brain form a massively parallel processor that provides the highest-bandwidth channel into human cognitive centers. At higher levels of processing, perception and cognition are closely interrelated, which is the reason why the words ‘understanding’ and ‘seeing’ are synonymous.

— Colin Ware, Information Visualization: Perception for Design, Academic Press, 2000

More recently, with the advent of the Internet and social media, infographics have been exploding in popularity. The New York Times, USA Today, and even the White House make regular use of infographics to present information that would be unwieldy to understand in its raw form, and there are several web sites now featuring an “infographic of the day” (Daily Infographic, Fast Company Infographic of the Day).

Anyone responsible for creating infographics in order to communicate complex information effectively can benefit by taking advantage of lessons from visual perception research.

Prof. Colin Ware, of the Data Visualization Research Lab at the University of New Hampshire, explains:

… the visual system has its own rules. We can easily see patterns presented in certain ways, but if they are presented in other ways, they become invisible. … The more general point is that when data is presented in certain ways, the patterns can be readily perceived. If we can understand how perception works, our knowledge can be translated into rules for displaying information. Following perception-based rules, we can present our data in such a way that the important and informative patterns stand out. If we disobey the rules, our data will be incomprehensible or misleading.

One important lesson we can leverage from vision science is an understanding of which elements will prominently “pop out” of an image — thanks to a mechanism known as “pre-attentive processing.” As our brains start to process an image, massively parallel processes detect image elements that are differentiated by low-level characteristics such as form, color, motion, and spatial position. The principles of pre-attentive processing govern which visual elements grab our attention first, before we’ve even begun to consciously process the image.

Here’s a simple example to illustrate the point. Count the number of 9’s appearing in this set of digits:

15483267910345782397345610238845923091236529573535279123853568223017452729283

Not so easy, was it? You had to scan all the digits in sequence. Now count the 9’s again:

15483267910345782397345610238845923091236529573535279123853568223017452729283

This time was a lot easier and quicker, thanks to the fact that our brains process lightness pre-attentively.

Some features that are pre-attentively processed include: color (hue and intensity), form (line orientation, line length and width, size, shape, curvature), motion (flicker, direction), and spatial position (2D position, spatial grouping).

For some more pre-attentive fun, visit the demo at this site, choose a feature, and see how immediately and easily your visual system is able to process it.

Understanding what kinds of features are pre-attentively processed has important implications for visual displays. When designing for critical situations such as air traffic control, flight display, or clinical care dashboards, it’s crucial to understand how to make certain symbols or elements stand out from others so they can be interpreted and acted upon immediately.

Likewise, if you’re designing infographics, it’s also important to understand which elements will be seen at first glance — they’re your first chance to grab your reader’s attention, even before conscious processing. Using color, size, shape, orientation, and other pre-attentive attributes, you’ll need to carefully craft which are the most important elements that should “pop out” first.

But choose carefully; not every element of your infographic can stand out. Vision science tells us that pre-attentive elements become less distinct as the assortment of patterns increases. Imagine a bumblebee swarming among flies; the bee is easy to pick out. Now imagine wasps, hornets, and yellowjackets joining the swarm, and the bumblebee will get lost in the mix. So it is with an infographic: As the multitude of competing pre-attentive elements increases, their “power to pop” will be diminished.

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