Bar charts can be ideal data visualization tools due to their simplicity, but sometimes the standard bar chart is actually too simple for the type of information you want to highlight. That’s when a variation of the bar chart, known as the stacked bar chart, can come into play.
Standard Bar Chart
Standard bar charts are excellent for illustrating straight-up comparisons, like comparing how many people make contact with your store using the phone, visiting in person or heading online to your website.
Visualizing the above data using a standard bar chart may look something like this:
While the standard chart works well for standard information, let’s say you wanted to dive deeper. Perhaps you want to know what means of contact people chose to perform various activities. For example, how frequently do people use the phone, visit in person or visit online to perform tasks such as:
- Researching items
- Purchasing items
- Requesting Returns
- Using coupons
While you could certainly attempt to map out the various activities on the standard bar chart, you would end up with a chart that was complicated and difficult to understand.
You would still have the phone, in person and online categories across the bottom of the chart, but each category would require four separate or columns, one for each activity. Instead of three main columns, your chart would feature 12 columns. Add the different colors and labels, and you’re adding yet another layer of complexity to what should be fairly straightforward data.
Enter the Stacked Bar Chart
With a stacked bar chart, your straightforward data remains straightforward, presented in a way that’s easy to understand. As the name implies, your data is stacked within each bar in segments.
In the example below, each bar has stacked data that represents the means of contacting your shop. Here you can quickly see that most people head online to research items – but request returns and use coupons most frequently in person.
Tips for Creating a Straightforward Stacked Bar Chart
- Be careful with your data set selection. Trying to cram too much data into the chart, or adding too many variables and labels, can only lead to confusion.
- Keep your data visualization streamlined by choosing no more than three segments for each bar. In our example, the three segments are modes of contact: phone, in person and online.
- Keep labels and other text to a minimum. Too much text can easily clutter up a chart. Only label information that is essential to the point you want to make. In our stacked bar chart example, we saw no need to label all the percentages or total number of visitors. The overall information we wanted to relay was the most frequent mode of contact for each activity.
- Choose colors that are easy on the eyes. Our standard bar chart example used three distinctly different colors. For the stacked bar chart example, we chose more subdued, complementary hues for a streamlined, professional appearance.
Most crosstab software packages and other data visualization tools will have a stacked bar chart option you can explore. Experiment with different variables, data sets and time spans, and you’ll quickly discover stacked bar charts may come to the rescue time and again for straightforward, comprehensible data visualization.