As a graphics designer, I have a love/hate relationship with circles. The humble form provides a relief from rigid rectangular chart structures that are pinned to x- and y-axes. The shape can certainly help to enliven a page and engage a reader. Using circles may come at a cost, however. The ability of a reader to make direct comparisons of exact measurements may be compromised (see a post I wrote in 2011 on the topic here–including the comments, which include a clarification). But depending upon the crux of the story, or context of the graphic, the tradeoff may be worth it.

A timeline in the form of a circle sparked a lively conversation on Twitter this past weekend. See designer and educator Alberto Cairo’s post “Redesigning a circular timeline,” in which he shares thoughts, responses and an alternate way to visualize the data presented in the original version of “Arab Spring” a graphic credited to Alexander Katin and Kir Khachaturov (featured by the Kantar Information is Beautiful Awards, 2013). His complaint: the original circular graphic was too hard to read, sacrificing the clarity of the information for the sake of beauty.

But something very important is missing: discussion of context. As I wrote in my 2011 post, “…context is key. I would hope that my doctor relies on excruciatingly clear and straightforward–if boring–data displays. Yet readers of Scientific American magazine may be better served by more engaging and dynamic charts.”

Not to say that I don’t consider those tradeoffs carefully and often opt to stick with a slightly less dynamic design solution when it better serves the information being presented. For example, for the upcoming March 2015 issue of the magazine, designer Tiffany Farrant-Gonzalez submitted several concept sketches, all based on the same data set (below). The circular form immediately captured my attention, but Farrant-Gonzalez and I agreed that one of the other versions would better serve the reader in the context of the story in our magazine.

Preliminary data sketches by Tiffany Farrant-Gonzalez

It all brings to mind one of my favorite sentiments from mathematician, science historian and poet Jacob Bronowski on the idea of context as a shaping force. In an essay on aesthetics and industrial design titled “The Shape of Things,” first printed in The Observer in 1952 (reprinted in The Visionary Eye) he wrote:

“The object to be made is held in a triangle of forces. One of these is given by the tools and the processes which go to make it. The second is given by the materials from which it is to be made. And the third is given by the use to which the thing is to be put. If the designer has any freedom, it is within this triangle of forces or constraints.”

To my mind, an information graphic or scientific illustration can be perceived as being wildly successful in one context, but fall flat in another context, simply due to the “use” variable.

Although some graphics can transcend their original context, every graphic is shaped by its initial triangle of constraints. I certainly have personal preferences and opinions about what makes a graphic more or less successful, and some solutions may ultimately work in many different contexts, but I love that there’s no single right answer. (For more of my thoughts on variation and experimental graphics, see “Behind the Curtain at Malofiej–Mecca for Visual Journalists”).