How Do You Read a Bubble Chart?

 

Proper data visualization is more important than ever before. Being able to clearly display insights brought on by dimensions of data is important to have a better picture of the findings of all of this information. There is a type of chart suited to just about every version of these datasets. Bubble charts have emerged as a way of displaying these findings in certain scenarios to provide a clearer look at the facts that can lead to better business decisions.

What are bubble charts?

A bubble chart, also referred to as a bubble plot or bubble graph, is used when data needs a third dimension to provide richer information. It’s designed to compare three variables. But unlike other three-dimensional charts that process data across three axes, bubble charts are represented on two axes with the size of the bubble communicating a third, vital piece of information. These charts visualize that critical third dimension of data, which may not be directly dependent on the first two dimensions.

Where a standard line chart may show a particular form of data, bubble graphs include extra information. And where a line graph would show how much is spent on a manufactured good, a bubble plot would highlight not only the manufacturing costs but the sales numbers across the items hitting the market. These charts are meant for studying relationships but not for representing exact data. The growth rate of a bubble’s size alone cannot provide accurate information on the rate of quantitative growth, but it does provide readers with an estimate to set the context of these quantities.

How do I read bubble charts?

A bubble chart, like every two-dimensional chart, starts with plotting X and Y axes. These variables are chosen for pre-existing relationships or to determine if there is a correlation among the chosen variables. The size of the bubble on a chart is used to represent the gravity of a parameter. For representing large data sets that need to be broken down, bubbles of different colors are used to mark differences across these sources. Just like any other graph, it’s all about implementing the best practices to emphasize important details across a set of values.

Every bubble chart can vary in its features, highlighting certain elements like outliers, bubbles that don’t behave like others on the chart. These outliers provide vital information whether it’s regarding supply chain development or understanding market share. Opposite to outliers are clusters on a bubble plot. These are groups of bubbles that are around the same, overlapping space on the chart based on a particular variable. Bubble charts may also feature gaps that warrant further investigation to understand if data is missing.

Why are these charts used?

A bubble chart is best for answering binary questions, simply “yes” or “no.” This is usually done by highlighting patterns that could derail if there is a connection between three variables or not. For example, if you were trying to understand population growth, you could look at bubble size in comparison to certain developments like an increase in schooling in the area or the availability of affordable housing. This allows for an overview that will call for additional information to explain a population shift beyond bubble size.

Bubble charts are also useful in the business sector, turned to for core financial processes like valuation and investment. For example, the cost of valuation can be studied against risk by using standard axes to represent cost and value, and the bubble sizes to represent risk.

Uncovering patterns based on different bubbles and different metrics allows for a greater sense of clarity and efficiency to then focus analytics for a full delve into the details an organization needs.