Divergent Stacked Bars & Survey Data

Last week, a colleague asked me to produce a visualization based on some recent survey data he had collected.  Prior to this project, I had only briefly worked with survey data for a small-scale project at work.  So I dug around in my Evernote archive and found some old articles that I had saved on how to effectively display survey data.

Here's the result I came up with...

As usual, I landed on a bar chart as the basis for my display.  Although I'd refer to this as a "divergent stacked bar chart" rather than a typical bar chart.

I had to do a bit of manual reshaping of the data in Excel to get it to play nicely with Tableau.  In particular I assigned a positive/negative string to each of the responses.  I then created a calculated field in Tableau that allowed me to plot the negative responses as a negative value, thus orienting them to the left of the base line.  Plotting the "negative" responses to the left of zero and the "positive" responses to the right of zero are what make this a divergent stacked bar chart.

I prefer the divergent stacked bar visual for this type of survey data because it allows the audience to easily compare the positive and negative responses.  It also clearly presents some relationships and insights.

Take for example, the relationship between age and interest in politics.  The divergent stacked bar approach very clearly shows that interest in politics increases with age, while increasing even more in respondents over the age of 65.

A typical bar chart (or column chart) as seen below doesn't communicate that message quite as effectively...

The divergent stacked bar approach also has the advantage of offering a large canvas for all of the demographic segments that are usually associated with survey data.  In this case I'm able to very succinctly communicate all of the responses from each demographic segment.

Once again, we see the power of the bar chart, or more appropriately, the effectiveness of assigning a value to the length of a bar.  It's not necessary to over-complicate a visualization that's tied to a somewhat complex data set (like survey data can often be).  Keep it simple, and make the bars work for you!

An interactive version of my survey sample can be seen here.  And a wealth of information on divergent stacked bar charts and communicating Likert survey results can be found here on Steve Wexler's fantastic Data Revelations blog.