Tips for Designing Bubble Charts

What’s a Bubble Chart?

Bubble Charts are versatile charts that allow the visualization of data sets made of two to four dimensions. Their most basic form, illustrate two dimensions of data: the first, a numerical value visualized as circular bubbles, and the second being what each bubble represents, where the larger the bubbles the larger the values. When three dimensions of data need to be visualized, Bubble Charts add functionalities to Scatter Plot Charts. Three dimensions Bubble Charts combine different-sized bubbles with the x and y axis; they are also known as “bubble plots”. When four dimensions of data need to be visualized different colors can differentiate categories.

When to Use Bubble Charts

Two dimensions Bubble Charts represent data sets made for example of percentages, illustrated as the size of the bubbles, and ranges visualized in the chart axis, they are great alternatives to bar charts. Three dimensions Bubble Charts represent the two data sets mentioned and a third one that is illustrated with varying bubble sizes; they are great for showing a clear correlation between expenses and sales as time advances. Four dimensions Bubble Charts, include the three data sets dimensions mentioned, plus a label for the bubbles; for example, they can compare birth rates in specific regions with low income and total world population.

Tips for Creating Bubble Charts

1. Make sure Bubble Charts labes are visible. This applies for every kind of chart. You won’t like your audience to miss your message.
2. Make sure bubble sizes are proportional. If you have a bubble with size x and another with 2x, the second should be twice as bigger to the first, not less or more.
3. Replacing bubbles with icons of other figures makes no good. This may cause confussion and your message may be misunderstood. Stick with bubbles.