Settling the Debate: Bars vs. Lollipops (vs. Dot Plots)

Studying the efficacy of data visualization archetypes with a user testing experiment

Examples of the chart types studied in this post, presented as candy. The Y-Axis represents silliness and, in the case of the bar chart, each bar’s height represents its own violation of the data-ink-ratio principle.

In 2017, some people were arguing on the internet. Notably, a few of them were thoughtful characters in the data visualization community, such as Stephen Few, Andy Cotgreave, Alberto Cairo, and Jeffrey Shaffer, to name a few.

The topic: What’s the value of a Lollipop chart? Is there something to the aesthetic (per Andy’s point)? Is the extra white space between symbols easier on our eyes (per Alberto)? Or are Lollipop charts just a “less effective version of a bar graph,” inspired by “the same thing that has inspired so many silly graphs: a desire for cuteness and novelty” (per Stephen)?

The discussion takes place in the comments on Stephen’s blog. Andy responds inline and with a post of his own. And, recently, Hicham Bou Habib summarized the discussion on Twitter, which is how I first discovered the controversy. (Thanks, Hicham!)

The debate unfolded over 24 days, from May 17 to June 10, 2017. The comments totaled about 10,000 words in response to a 400 word blog post.

Why not just test it?

What stood out to me: Why not just test it out? What’s the opportunity cost for…