data-viz-workshop-2021

Five qualities of great visualizations

1. Truthful

Your graphic should be based on thorough and honest research.

Whenever a designer, journalist, PR person, advertiser, or your own sweet Auntie Julie shows you a visualization with just a few figures resulting from adding up, rounding, or averaging tons of data, distrust them. If someone hides data from you, it’s probably because he has something to hide. - Alberto Cairo.

Truth and untruth aren’t absolutes, and they are the extremes at either end of a spectrum.

Here is an example of a deceptive and dishonest graphic. The graphic below shows the production cost of two products. They co-vary, don’t they? Maybe not. Notice that the chart has two Y-axes; it is a dual-axis chart. Using two vertical axes and omitting zero from either or both opens a statistical beauty parlor with many cosmetic possibilities.

Not all charts need a zero baseline, but being careless with scales and axes is always dangerous. The data look quite different if we plot the lines on the same scale:

2. Functional

Your graphic should constitute an accurate depiction of the data. And it is built in a way that lets people do meaningful operations based on it.

If getting your information right is the most important step in creating any visualization, the second one is helping the audience interpret it correctly.

In the following graph, the percentages in the second pie chart are hidden on purpose. The goal of these charts is to help people estimate change – that’s the explicit headline. Try to compare the popularity of hip-hop in 1994 and in 2014. Was reggae more popular in 2014 than in 1994? And Samba? It is clear that country and classic were equally famous in 1994, but what about 2014?

A slope chart could be better used to display the exact same data:

The purpose of your graphics should somehow guide your decision of how to shape the information.

3. Beautiful

Your graphic should be attractive, intriguing, and even aesthetically pleasing for its intended audience – scientists, in the first place, but the general public, too.

Of the two charts, which is more aesthetically pleasing?

Regardless of age, gender, race, or educational background, an overwhelming majority of readers would agree that the second chart feels more aesthetically pleasing (and, therefore, closer to being beautiful) than the first one. They both present the same content, but the second one makes it simpler, clearer, and more elegant.

What matters isn’t if the objects of our creation are beautiful or not per se, but if they are experienced as beautiful by as many people as possible. It can be all relative, too.

4. Insightful

A graphic should reveal evidence that we would have a hard time seeing otherwise. The purpose of visualization is insight, not pictures.

Here is an example of an insightful graphic included in the paper “Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group”:

5. Enlightening

If we grasp and accept the evidence depicted by the graphics, it will change our minds for the better. - Source: TTA.

Ultimately, the goal of any candid visual communicator is to give people access to the information they need to increase their well-being. Great visualizations change people’s minds for the better, and they are enlightening.

An enlightening graphic is a consequence of paying attention to the previous four qualities. A truthful, functional, beautiful, and insightful graphic has the potential of being enlightening as well. But there’s something else to consider at this point: the topic of the visualization.

Choosing topics ethically and wisely – casting light over relevant issues – matters a lot.