bar graphs | Presentation Xpert

A Primer for Creating Diverging Stacked Bar Charts

When I first heard the name of this visual, diverging stacked bar chart, it seemed complex. As I learned more about it, I realized how valuable it is to know about this type of visual in business presentations.

Let’s start with an example of such a visual:

A diverging stacked bar chart is a bar chart that can have one or more segments on each side of a dividing line. The dividing line separates the two groups or categories of data. The above example has only one segment on each side of the dividing line (which is not explicitly shown) and the two groups of data are hardware sales (HW) and software sales (SW).

The reason that this type of graph works well is that it allows the viewer to easily compare the relative size of each group of related data. Each group starts at the dividing line and moves either right or left. In the above example, it is easy to see that in each year software sales are much larger than hardware sales.

Here is another example. In this case, there are multiple segments on each side of the dividing line. The dividing line here represents the goal for customer service ratings (8 out of a possible perfect score of 10). To the left of the line are the ratings below the goal and to the right of the line are the ratings above the goal. The more the overall bar is to the right, the more that call center has ratings above the goal.

It is easy for the audience to see how much of the bar is to the right of the dividing line, indicating performance above the goal. Because we wanted to also see the breakdown of scores on each side of the goal, the data is broken down into segments based on the score given by the customer (5 or lower, 6-7, 8-9, and 10). There are more good examples in this article by Darkhorse Analytics.

It seems like this would be a complicated graph to create, but it is actually much easier due to an online calculator I created. You can use the Diverging Stacked Bar Chart Calculator to calculate the values you enter into the data table for a regular stacked bar chart in Excel or PowerPoint. The values to the left of the dividing line are negative and the calculator organizes them so that they appear correctly. The calculator page has additional ideas on formatting the chart and adding text labels to create the type of charts you see above.

When you want to communicate the values of two groups of data that are related, consider whether a diverging stacked bar chart would work for you.

About the Author:

Dave Paradi runs the Think Outside the Slide website, is a consultant on high-stakes presentations, the author of seven books and a PowerPoint Most Valuable Professional (MVP.) For more information, visit www.thinkoutsidetheslide.com

Tired of Bar Graphs? Compare Values by Using Proportional Shapes

Last year I created an online tool to calculate the sizes of two shapes based on values that you input. This allows you to create a diagram with two proportional shapes (see below). I wrote about this calculator in an issue of my newsletter and gave examples of the background and other links about this type of diagram.

At the 2013 Presentation Summit, fellow PowerPoint MVP Glenna Shaw of visualology.net suggested that what I had created was good, but needed to go further.

Glenna had written about the online tool in blog posts for Microsoft (see my newsletter above for links), but she wanted it to do more. She wanted the tool to calculate the sizes of more than two shapes. This would allow it to be used when you have more than two values to compare visually. She also wanted it to be more generic, so the sizes could apply to any shape or image, not just squares, rectangles, and circles.

Of course her ideas made perfect sense. So I went to work in my hotel room that day and created a new tool, the Proportional Object Collection Calculator. It allows you to create slides like this:

This example of a proportional object collection shows one of the shapes only partially on the slide. When one of the values is much larger than the rest of the values, this approach can work well because it allows the shapes for the smaller values to be more easily seen on the slide. The audience still understands the magnitude of the large shape because more than half of it is on the slide.

To use the calculator, enter the height and width of the largest object you want to create (in inches or centimeters). Then you enter the values you want to represent with proportional objects. Enter the values in order from largest to smallest.

In the Results section, you will see exact measurements for each object. Use the entry fields in the Size group for the object to enter the height and width shown in the Results table.

I have found it easiest to copy the results table of object sizes onto my slide so it is easy to see when entering the sizes for each shape or image. You can make the table smaller if it is taking up too much room, and move it to one of the top corners of the slide so it is out of the way of where you are placing the objects.

When you’re done, you can delete the table or move it to the Notes section of the slide if you need to keep the dimensions of the objects.

Instead of a column or bar graph, consider using a proportional object collection in your next presentation. It tells the story of the numbers visually in a way the audience will understand and remember.

About the Author: