Source: Diagrams by Arthur Lockwood published in 1966. “Graph from scientific magazine showing US annual energy consumption of various energy sources: wood, hydro-electricity, gas, oil and coal. Use of third dimension to differentiate and dramatize information.”
From COVID-19 cases to the election and beyond, we’ve seen a lot of charts and graphs in the past year. And these include maps, bars, pies, dendrograms, heat, bubbles—frankly people are using everything they can think of to explain the data.
Graphs and charts are a great way to show information, but they need to make a point and they need to be trustworthy. In Data Visualization, Andy Kirk explains, “Being truthful and avoiding deception in how you portray data visually are fundamental obligations.”
If a chart is complicated, it’s hard for people to understand it and relate to the information it contains. In successful charts you don’t always need a multitude of words, labels and numbers. Check out the visualization from Reuters showing how plastic bottles are piling up in the world. This graphic needs no numbers because the explanation and the visual tell the complete story in a compelling way.
PowerPoint and Excel have, in a way, reduced charts to a generic and elementary form. These programs come with default chart types, typography and colors, and while helpful, they are just that—generic.
Below are some helpful tips for creating successful charts and graphs:
– Label each axis, this is simple but important
– Identify the components clearly—use a legend or some other way to describe what each color/shape/line means
– Quantify the units—is it a percentage or dollar amount or something else?
– Pay attention to geometry especially in charts that use bubble plots: circles should be measured by area, not diameter
– Always include sources
– Understand the prospective use. Is the chart part of a page in a presentation you’re giving? Or is it something your readers will keep and take the time to digest?
– Use simple typography and focus on readability
If the chart isn’t making the point you want, then perhaps you have the wrong data or need to show it in a different way.
Spread from Envisioning Information by Edward R. Tufte, 1990. (p. 24-25)
Do you love seeing the graphic representation of information? Here are some sources you might find interesting.
Data Visualization: A handbook for data driven design by Andy Kirk
From the renowned visual information design master, Edward Tufte, Envisioning Information, as well as other books he wrote.