In my previous post, I looked into the magic mirrors of business leaders, more commonly called dashboards, as one example of how data visualization is used.  In this post, I want to look at what we use to look — our eyes — and how they process whatever data we visualize.

In his book Incognito: The Secret Lives of the Brain, David Eagleman explained how our brain samples just a small bit of the physical world, making time-saving assumptions and seeing only as well as it needs to.  As our eyes interrogate the world, they optimize their strategy for the incoming data, arbitrating a battle between the conflicting information.  What we see is not what is really out there, but instead only a moment-by-moment version of which perception is winning over the others.

Therefore, our visual perception works not by building up bits of captured data, but instead by matching our expectations to the incoming sensory data — and it’s our expectations that can distort the data we visualize a lot more than we may realize.

In her blog post Seeing Will Be Believing for the Business, Beth Schultz explained “data visualizations are sure to open a few eyes.  Data visualizations might be a great way to deliver analytical insights to business users, but that doesn’t mean you load up the visual dashboard and get out of the way.”

I agree with Schultz because even though seeing will be believing for your business users, sometimes you will not believe what business users see in your data visualizations.

And I don’t just mean poorly designed data visualizations, which are more like a 3D autostereogram painting that has to be viewed cross-eyed in order to be able see its hidden image.

I am not trying to convince you to not use data visualizations.  However, since some business users might not look deeper into the data beyond what is visualized in dashboards, it begs the question, when it comes to understanding data, do the eyes have it?

And even if you think they do, it’s always a good idea to ask your business users what exactly is the it that their eyes have found in your data visualizations, since their answers may be eye-openers.