Sail Forth- Steer for the deep waters only. Reckless O soul, exploring. I with thee and thou with me. For we are bound where mariner has not yet dared go. And we will risk the ship, ourselves, and all.
-Walt Whitman
I consider myself a novice, for now, staying safe in the shallow waters of data visualization. I’ve learned to create clean and modern-looking bar, column, and {gulp!} the occasional pie charts. I follow basic safety rules, dispensing with the unnecessary – gridlines, tick marks, superfluous axis labels and legends. I avoid default colors, and proudly leave 3D charts to the real amateurs. To venture beyond that, into the deep current of dashboards and interactivity, I would need a life jacket and tow rope. Recently, though, I waded a bit deeper, and experimented with two variations – back-to-back bar charts and small multiples. In this post, I share how I created my first back-to-back bar chart. Part II will tackle the small multiples.
I created a back-to-back bar chart to display some common public school data. Much of this process I learned from Stephanie Evergreen’s blogs on dataviz. I chose a back-to-back bar chart because I have two datasets that people need to see in one chart, yet they don’t necessarily need to compare one dataset (Math) to the other (ELA). What they do want to compare is one year to the next for each grade level.
Here is how to do it:
- Create one horizontal bar chart.
- Make these basic changes:
- DELETE gridlines, x-axis tick marks and line, y-axis, chart border. (NOTE: I could have deleted the x-axis as well, but I left it in this chart for the purpose of drawing the reader not just to the absolute scores, but to the scores as compared to 100%)
- ADD data labels and title.
- FORMAT fonts (larger, bold).
- ADJUST colors (I used colors associated with the organization)
- REDUCE gap width (I chose 40% for this graph).
- When you have everything looking the way you want it to on the first graph, create the second by copying the first and editing the data.
- Click “select data” and edit to get the correct data on the chart.
- FLIP the graph on the left (my Math graph) by right clicking on the x-axis, and checking “values in reverse order.”
- INSERT text boxes in the top bars of each graph to identify the years (this eliminates the need for the legend).
- INSERT text boxes in the center (between the two graphs) for the shared y-axis (I created one – Grade 3), then copied, pasted, and aligned it, and then replaced the text for the other grade levels).
- OUTLINE the bars in white, (a cool trick I learned from Ann K Emery’s blogs about dataviz) and increase the line weight bit (I put it up to 1.25).
- GROUP graphs by selecting both along with all text boxes and right click to “group” them. Grouping can be tricky in Excel and when you go to copy and paste, be sure to grab the grouped object, rather than just the graph.
SUCCESS! Go on, try it yourself! You know you want to…
Look for Part II on small multiples…coming soon.