A diverging bar chart is a bar chart that has the marks for some dimension members pointing up or right, and the marks for other dimension members pointing in the opposite direction (down or left, respectively). What’s unique about a diverging bar chart is the marks flowing down or left do not necessarily represent negative values. The divergent line can represent zero, but it can also be used to simply separate the marks for two dimension members, to represent a goal, or – as often seen with survey data – to show the break between desired and undesired responses. The drawback to using diverging bar charts is that it’s not as easy to compare the values across dimension members as it is with a grouped bar chart. If, on the other hand, your primary objective is to compare the trend of each individual dimension member, a divergent bar chart is a good option. I also feel that this chart type helps declutter a grouped bar chart, making the data more engaging and easier to understand. In this post, we will reverse engineer my viz, 50 Years of AFC vs. NFC Matchups, to show you two different approaches to creating diverging bar charts in Tableau.
