In elementary school, we were introduced to graphs and charts. We were taught how to find the x- axis, the different types of graphs, and how to plot points. We also learned, that charts are like pictures–they help tell a story and add credibility. But graphs should really be looked at with a close eye, as some can skew data to support the writer’s own narrative and mislead readers.
The information isn’t always wrong, but the way in which it is presented can be deceptive. Take this scenario for example:
Hurricane Judy, a made-up storm, is headed to the eastern coast of the United States. To make sure they were in the clear, a student visits their local news site to track its progress. They breathe out a breath of fresh after seeing the outer rim of the cone of the storm had just missed their hometown, Miami. But, are they really in the clear? The answer is no. What most people don’t know is that hurricane maps are extremely oversimplified and do not give readers an accurate prediction of where the storm is going to go.
These cones only represent the range of possibilities of where the storm could be in five days. The path of a hurricane is always changing and growing in size, meaning there is room for uncertainty. Also, being outside of the perimeter of the cone does not take into account hurricane-like conditions, which include strong winds and flash floods. Graphs like these become a liability if people think they are in the clear when they are not.
This example is only a glimpse into how deceptive and misleading charts can be if you are not paying close attention. Alberto Cairo, associate professor and knight chair in visual journalism, is a leading expert on the subject and has appeared on numerous news outlets including The New York Times, BBC, and NPR to provide his insight. His new book How Charts Lie, in-stores Oct. 15, illustrates how students can navigate around misleading patterns and take advantage of the good ones to understand complex arguments. To ensure you aren’t getting caught up in the lies, here are the takeaways from Cairo’s new book:
We tend to associate charts with pictures, leading us to believe they are intuitive and don’t require focus to understand them. However, if a picture is worth a thousand words, we should be devoting the same amount of attention we would to an essay. Cairo suggests taking a couple of minutes to read the chart and interpret it before deeming it credible.
Check the source
Ever heard of fake news? In this post-truth era, we’ve been cautioned to be mindful of sources when you find a story too good to be true. If your graph is coming from a less-than-reputable source, chances are it’s not the most reliable, especially if there is no source at all.
”If the chart has no indication where it came from, just throw it away.” Cairo says.
A reliable graph should always cite the source.
Check for distortion
Cairo points out an easy way to know if a chart is skewed is when the margins have been distorted such as not having the baseline at zero. This can make differences in data seem more drastic than not. Check the margins to see if the author of the graph is expanding or compressing the scale which is another way writers manipulate how change overtime is presented.
The graph should indicate what is measured
A good visual argument has to declare what it is measuring to make it abundantly clear to its viewers. That includes defining axis labels as well as defining any terms. Cairo gives us an example of what happens when you look for statistics on inter-partner violence. Different sources from all over the world will give you different numbers based on how they define
inter-partner violence. Some might only count physical violence, while others include emotional abuse in their definition. It is important to take note of these subtleties, as they can make all the difference in your search for accurate information.
Don’t project your own bias
As humans, we tend to settle for the first piece of information that supports our own argument. This is when our own bias leads us to be manipulated by distorted data. Just like any argument, graphs are tools that enable conversation and make decisions. Try to be mindful of your own bias while analyzing data before sharing, as we tend to project the information we want to find.
Bottom line is, the ways graphs are distorted to mislead readers all boils down to how closely a graph is looked at. Misleading charts are much more common than people might think and can have serious repercussions if used inappropriately. If you see a very complex concept illustrated in a simple way, take a few extra minutes to examine the information before including it in a report or presentation.