Recently, our cohort explored the amazing books available to us in The Information Lab library. One particular book caught my eye: The Truthful Art by Alberto Cairo.
Cairo is one of the big names in the field. He is an educator, consultant, and the Knight Chair in Visual Journalism at the University of Miami. As a scientist, I have always seen myself as devoted to the truth, only the truth, and nothing but the truth. So I dived right into this book with great enthusiasm and immediately loved his lively and gripping writing style.
In one chapter, Cairo describes the five qualities that make a visualization great:
- Truthful
- Functional
- Beautiful
- Insightful
- Enlightening
1. Truthful
“Truth and untruth aren’t absolutes. They are the extremes at either end of the spectrum.” (p. 45)
Even without outright "lying" by using made up data, you can deceive your audience in many ways. You can leave out data that does not fit your narrative, or aggregating it in a misleading way, you can use charts with dual axes that are not synchronized or start your axes at zero. It is not only morally wrong but will in the end harm your own credibility.
Cairo advises that truthfulness comes down to being honest with yourself and with your audience. This means applying critical thinking, not jumping to conclusions and avoiding succumbing to your own biases.
2. Functional
A functional chart chooses the right form for the task. For example, change over time is depicted clearly in a slope chart, but far less effectively in two separate pie charts.
3. Beautiful
Cairo argues that an aesthetically pleasing chart gets the message across better. Beautiful charts are elegant and simple; they lack "chart junk" and 3D effects, making them clearer to read and more pleasant to perceive.
4. Insightful
A visualization is insightful if it allows the audience to make a discovery that wouldn't be possible otherwise. Insight means both “spontaneous insight (an 'A-ha!' moment) and knowledge-building insight, coming from exploring the data gradually.”
A great visualization makes evident "what hid behind a veil of complexity." (p.60)
5. Enlightening
An enlightening visualization requires the previous four components but adds the ethical choice of topic. This is not meant as much in a dogmatic way, but that we should devote more of our limited time to data visualizations that are meaningful.
Cairo argues that “some topics do matter more than others indeed because they are more critical to the well-being of more people.” (p. 63)
My two cents
Personally, I think what makes a visualization "great" very much depends on the context. Cairo's work is all about journalism and infographics; here his list makes fully sense. In the world of business dashboards, being "enlightening" is less of a priority than being "actionable."
However, one item I personally would add to Cairo’s list is not a trivial one: a great visualization should be accessible. This goes for business dashboards as well as infographics. If your chart cannot be clearly perceived by someone who is colorblind, regardless of how beautiful or truthful it is, then it is not a great visualization.
Source:
- Book: The Truthful Art: Data, Charts, and Maps for Communication
- Author: Alberto Cairo (2016)
- Publisher: New Riders