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Why reading charts is hard & How language and visual metaphors can help 

Steve Franconeri, (add photo of Steve) a Psychology professor at Northwestern and SILC advisory board member, studies how people process visual information. People often fail to perceive uncertainty in charts and take graphs as a literal representations. Northwestern Magazine feature Franconeri alongside Dr. Jessica Hullman  in the article, “Understanding Uncertainty” which touched on how better to present data visually so the layperson can best understand polling data.  Franconeri offered his expertise on how graphic systems relate to the human visual system to contribute data visualization suggestions to journalists. Here we expand on the spatial foundations of Steve Franconari’s work to shed light on how humans read charts, why it’s hard for some and how his visual spatial research helps.

Charts and bar graphs exist within a visual space and rely on the human visual system to extract relationships from the 2D information. The information extracted pertains to how the variables within the 2D system relate to each other on a visual plane. Reading a graph isn’t as cognitively simple as it may seem. A graph with three bars requires a viewer to consider multiple pieces of information and reach a conclusion. “In order to do that visually you have to do some visual spatial gymnastics in your head, where you have to imagine the average of just these two bars versus those two bars or the delta between these bars versus those bars. And that’s really tough to learn.”

No one fully understands how or why some people are naturally better at visually extracting information from 2D systems. However, research by Franconeri’s colleagues, have found language can help guide the reader’s attention to pull out spatial relationships (Link/ Introduce Article). Imagine a newspaper presents a three-bar-graph of the number of Democratic, Republican, and Third Party voters in Illinois, and someone asks you “Are there more Democrats than Republicans in Illinois?” Versus if this person asked you “Are there less Republicans than there are Democrats?” (Use another example from Steve’s research/ adult related) As a reader, you have to the consider the bars for each category, and depending on how the question is asked, you look at the bars in a different order because your brain processes this information differently. (Ask Steve to elaborate on this) This simple example illustrates how important it is to coordinate language with the visual space a viewer is asked to consider.   (add figure from article or related photo)

The human brain perceives simple reversals as very different sentences. “If I said I was at a party last weekend and said I met Hillary Clinton versus if I said I was at a party last weekend and Hillary Clinton met me.” Even though both sentences deliver the same information about the main event, you know there is a difference. “We try to show that the way that language guides your attention helps you pull spatial relationships out of the world.” Groups or people interested in data visulization, such as journalists, academics, or student, can leverage natural metaphors of seeing events unfold or looking at a set of objects using a visual spatial system to understand data presented.

Those who are more versed in statistics or accustomed to reading 2D visualizations of data may often use shapes to understand the relationships between variables on a chart. “The 2D visual spatial system lets you see patterns that are tough to see before. 2D patterns let you see relationships as shapes” said Franconeri. There are limits to how much the human brain can visualize even in people who are really good at doing this. The work of Franconeri is helping us understand what’s going on in the brains of people who are naturally able to perform complex visual spatial tasks to apply this knowledge in real world contexts.